Specification: Jakarta EE Platform Version: 8 Status: Final Release Release: August 26, 2019
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1. Introduction
Enterprises today need to extend their reach, reduce their costs, and lower the response times of their services to customers, employees, and suppliers.
Typically, applications that provide these services must combine existing enterprise information systems (EISs) with new business functions that deliver services to a broad range of users. The services need to be:
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Highly available, to meet the needs of today’s global business environment.
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Secure, to protect the privacy of users and the integrity of the enterprise.
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Reliable and scalable, to ensure that business transactions are accurately and promptly processed.
In most cases, enterprise services are implemented as multitier __ applications. The middle tiers integrate existing EISs with the business functions and data of the new service. Maturing web technologies are used to provide first tier users with easy access to business complexities, and eliminate or drastically reduce user administration and training.
The Jakarta™ EE Platform reduces the cost and complexity of developing multitier, enterprise services. Jakarta EE applications can be rapidly deployed and easily enhanced as the enterprise responds to competitive pressures.
Jakarta EE achieves these benefits by defining a standard architecture with the following elements:
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Jakarta EE Platform - A standard platform for hosting Jakarta EE applications.
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Jakarta EE Compatibility Test Suite - A suite of compatibility tests for verifying that a Jakarta EE platform product complies with the Jakarta EE platform standard.
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Jakarta Compatible Implementations - Certified implementations for building and deploying Jakarta EE applications.
This document is the Jakarta EE platform specification. It sets out the requirements that a Jakarta EE platform product must meet.
1.1. Acknowledgements for the Initial Version of Java EE
This specification is the work of many people. Vlada Matena wrote the first draft as well as the Transaction Management and Naming chapters. Sekhar Vajjhala, Kevin Osborn, and Ron Monzillo wrote the Security chapter. Hans Hrasna wrote the Application Assembly and Deployment chapter. Seth White wrote the JDBC API requirements. Jim Inscore, Eric Jendrock, and Beth Stearns provided editorial assistance. Shel Finkelstein, Mark Hapner, Danny Coward, Tom Kincaid, and Tony Ng provided feedback on many drafts. And of course this specification was formed and molded based on conversations with and review feedback from our many industry partners.
1.2. Acknowledgements for Java EE Version 1.3
Version 1.3 of this specification grew out of discussions with our partners during the creation of version 1.2, as well as meetings with those partners subsequent to the final release of version 1.2. Version 1.3 was created under the Java Community Process as JSR-058. The JSR-058 Expert Group included representatives from the following companies and organizations: Allaire, BEA Systems, Bluestone Software, Borland, Bull S.A., Exoffice, Fujitsu Limited, GemStone Systems, Inc., IBM, Inline Software, IONA Technologies, iPlanet, jGuru.com, Orion Application Server, Persistence, POET Software, SilverStream, Sun, and Sybase. In addition, most of the people who helped with the previous version continued to help with this version, along with Jon Ellis and Ram Jeyaraman. Alfred Towell provided significant editorial assistance with this version.
1.3. Acknowledgements for Java EE Version 1.4
Version 1.4 of this specification was created under the Java Community Process as JSR-151. The JSR-151 Expert Group included the following members: Larry W. Allen (SilverStream Software), Karl Avedal (Individual), Charlton Barreto (Borland Software Corporation), Edward Cobb (BEA), Alan Davies (SeeBeyond Technology Corporation), Sreeram Duvvuru (iPlanet), B.J. Fesq (Individual), Mark Field (Macromedia), Mark Hapner (Sun Microsystems, Inc.), Pierce Hickey (IONA), Hemant Khandelwal (Pramati Technologies), Jim Knutson (IBM), Elika S. Kohen (Individual), Ramesh Loganathan (Pramati Technologies), Jasen Minton (Oracle Corporation), Jeff Mischkinsky (Oracle Corporation), Richard Monson-Haefel (Individual), Sean Neville (Macromedia), Bill Shannon (Sun Microsystems, Inc.), Simon Tuffs (Lutris Technologies), Jeffrey Wang (Persistence Software, Inc.), and Ingo Zenz (SAP AG). My colleagues at Sun provided invaluable assistance: Umit Yalcinalp converted the deployment descriptors to XML Schema; Tony Ng and Sanjeev Krishnan helped with transaction requirements; Jonathan Bruce helped with JDBC requirements; Suzette Pelouch, Eric Jendrock, and Ian Evans provided editorial assistance. Thanks also to all the external reviewers, including Jeff Estefan (Adecco Technical Services).
1.4. Acknowledgements for Java EE Version 5
Version 5 (originally known as version 1.5) of this specification was created under the Java Community Process as JSR-244. The JSR-244 Expert Group included the following members: Kilinc Alkan (Individual), Rama Murthy Amar Pratap (Individual), Charlton Barreto (Individual), Michael Bechauf (SAP AG), Florent Benoit (INRIA), Bill Burke (JBoss, Inc.), Muralidharan Chandrasekaran (Individual), Yongmin Chen (Novell, Inc.), Jun Ho Cho (TmaxSoft), Ed Cobb (BEA), Ugo Corda (SeeBeyond Technology Corporation), Scott Crawford (Individual), Arulazi Dhesiaseelan (Hewlett-Packard Company), Bill Dudney (Individual), Francois Exertier (INRIA), Jeff Genender (The Apache Software Foundation), Evan Ireland (Sybase, Inc.), Vishy Kasar (Borland Software Corporation), Michael Keith (Oracle Corporation), Wonseok Kim (TmaxSoft, Inc.), Jim Knutson (IBM), Elika Kohen (Individual), Felipe Leme (Individual), Geir Magnusson Jr. (The Apache Software Foundation), Scott Marlow (Novell, Inc.), Jasen Minton (Oracle Corporation), Jishnu Mitra (Borland Software Corp), David Morandi (E.piphany), Nathan Pahucki (Novell, Inc.), David Morandi (E.piphany, Inc.), Ricardo Morin (Intel Corporation), Nathan Pahucki (Novell, Inc.), Matt Raible (Individual), Dirk Reinshagen (Individual), Narinder Sahota (Cap Gemini), Suneet Shah (Individual), Bill Shannon (Sun Microsystems, Inc.), Rajiv Shivane (Pramati Technologies), Scott Stark (Jboss, Inc), Hani Suleiman (Ironflare AB), Kresten Krab Thorup (Trifork), Ashish Kumar Tiwari (Individual), Sivasundaram Umapathy (Individual), Steve Weston (Cap Gemini), Seth White (BEA Systems), and Umit Yalcinalp (SAP AG). Once again, my colleagues at Sun provided invaluable assistance: Roberto Chinnici provided draft proposals for many issues related to dependency injection.
1.5. Acknowledgements for Java EE Version 6
Version 6 of this specification was created under the Java Community Process as JSR-316. The spec leads for the JSR-316 Expert Group were Bill Shannon (Sun Microsystems, Inc.) and Roberto Chinnici (Sun Microsystems, Inc.). The expert group included the following members: Florent Benoit (Inria), Adam Bien (Individual), David Blevins (Individual), Bill Burke (Red Hat Middleware LLC), Larry Cable (BEA Systems), Bongjae Chang (Tmax Soft, Inc.), Rejeev Divakaran (Individual), Francois Exertier (Inria), Jeff Genender (Individual), Antonio Goncalves (Individual), Jason Greene (Red Hat Middleware LLC), Gang Huang (Peking University), Rod Johnson (SpringSource), Werner Keil (Individual), Michael Keith (Oracle), Wonseok Kim (Tmax Soft, Inc.), Jim Knutson (IBM), Elika S. Kohen (Individual), Peter Kristiansson (Ericsson AB), Changshin Lee (NCsoft Corporation), Felipe Leme (Individual), Ming Li (TongTech Ltd.), Vladimir Pavlov (SAP AG), Dhanji R. Prasanna (Google), Reza Rahman (Individual), Rajiv Shivane (Pramati Technologies), Hani Suleiman (Individual).
1.6. Acknowledgements for Java EE Version 7
Version 7 of this specification was created under the Java Community Process as JSR-342. The Expert Group work for this specification was conducted by means of the http://javaee-spec.java.net project in order to provide transparency to the Java community. The specification leads for the JSR-342 Expert Group were Bill Shannon (Oracle) and Linda DeMichiel (Oracle). The expert group included the following members: Deepak Anupalli (Pramati Technologies), Anton Arhipov (ZeroTurnaround), Florent Benoit (OW2), Adam Bien (Individual), David Blevins (Individual), Markus Eisele (Individual), Jeff Genender (Individual), Antonio Goncalves (Individual), Jason Greene (Red Hat, Inc.), Alex Heneveld (Individual), Minehiko Iida (Fujitsu), Jevgeni Kabanov (Individual), Ingyu Kang (Tmax Soft, Inc.), Werner Keil (Individual), Jim Knutson (IBM), Ming Li (TongTech Ltd.), Pete Muir (Red Hat, Inc.), Minoru Nitta (Fujitsu), Reza Rahman (Caucho Technology, Inc), Kristoffer Sjogren (Ericsson AB), Kevin Sutter (IBM), Spike Washburn (Individual), Kyung Koo Yoon (TmaxSoft).
1.7. Acknowledgements for Java EE Version 8
Version 8 of this specification was created under the Java Community Process as JSR-366. The Expert Group work for this specification was conducted by means of the http://javaee-spec.java.net and https:javaee.github.io/javaee-spec projects in order to provide transparency to the Java community. The specification leads for the JSR-366 Expert Group were Bill Shannon (Oracle) and Linda DeMichiel (Oracle). The expert group included the following members: Florent Benoit (OW2), David Blevins (Tomitribe), Jeff Genender (Savoir Technologies), Antonio Goncalves (Individual), Jason Greene (Red Hat), Werner Keil (Individual), Moon Namkoong (TmaxSoft, Inc.) Antoine Sabot-Durand (Red Hat), Kevin Sutter (IBM), Ruslan Synytsky (Jelastic, Inc.), Markus Winkler (oparco - open architectures & consulting). Reza Rahman (Individual) participated as a contributor.
1.8. Acknowledgements for Jakarta EE 8
The Jakarta EE 8 specification was created by the Jakarta EE Working Group within the Eclipse Foundation https://jakarta.ee/
2. Platform Overview
This chapter provides an overview of the Jakarta™ EE Platform.
2.1. Architecture
The required relationships of architectural elements of the Java EE platform are shown in Jakarta EE Architecture Diagram. Note that this figure shows the logical relationships of the elements; it is not meant to imply a physical partitioning of the elements into separate machines, processes, address spaces, or virtual machines.
The Containers, denoted by the separate rectangles, are Jakarta EE runtime environments that provide required services to the application components represented in the upper half of the rectangle. The services provided are denoted by the boxes in the lower half of the rectangle. For example, the Application Client Container provides Jakarta Messaging APIs to Application Clients, as well as the other services represented. All these services are explained below. See Jakarta EE Standard Services.
The arrows represent required access to other parts of the Jakarta EE platform. The Application Client Container provides Application Clients with direct access to the Jakarta EE required Database through the Java API for connectivity with database systems, the JDBC™ API. Similar access to databases is provided to server pages, server faces applications, and servlets by the Web Container, and to enterprise beans by the Enterprise Beans Container.
As indicated, the APIs of the Java™ Platform, Standard Edition (Java SE), are supported by Java SE runtime environments for each type of application component.
The following sections describe the Jakarta EE Platform requirements for each kind of Jakarta EE platform element.
2.2. Profiles
The Java EE 6 specification introduced the notion of “profiles” (see Profiles”).
A profile is a configuration of the Jakarta EE platform targeted at a specific class of applications.
Profiles are not a new concept, nor are they unique to the Jakarta EE platform. The Jakarta EE Specification process: “A Specification that includes by reference a collection of Specifications and possibly additional requirements. APIs from the referenced Platform Edition must be included according to the referencing rules set out in that Platform Edition Specification. Other referenced specifications must be referenced in their entirety.”
All Jakarta EE profiles share a set of common features, such as naming and resource injection, packaging rules, security requirements, etc. This guarantees a degree of uniformity across all products and, indirectly, applications that fall under the “Jakarta EE platform” umbrella. This also ensures that developers who are familiar with a certain profile, or with the full platform, can move easily to other profiles, avoiding excessive compartmentalization of skills and experience.
Beyond the basic functionality outlined above, profiles are free to include any set of technologies that are part of the platform, provided that all rules in the present specification that pertain to the included technologies—either alone or in combination with others—are followed.
This last point is worth stressing. If profiles only included pointwise technologies, they would be little more than bundles of APIs with few or no tie-ins. Instead, the definition of profiles adopted here guarantees that whenever this specification defines requirements on combinations of technologies, these requirements will be honored in all products based on Jakarta EE profiles.
As a concrete example, consider the use of transactions in a servlet container. In isolation, neither the Jakarta Servlet specification nor the Jakarta Transactions specification defines a complete programming model for portable applications. This specification fills that gap by introducing its own set of requirements that pertain to the combination of servlets and Jakarta Transactions. These requirements must be satisfied by any Jakarta EE profile-based product that includes those two technologies, thus offering application developers a more complete programming model shared across all relevant Jakarta EE profiles.
A separate specification, the Jakarta EE Web Profile Specification, defines the Jakarta EE Web Profile, the first profile of the Jakarta EE platform.
Additional profiles may be defined in accordance with the rules of the Jakarta EE Specification Process and those contained in the present specification. In particular, profiles are initiated by submitting a Project Proposal to the Jakarta EE Specification Process and are released at completion on their own schedule, independently of any concurrent revision of the platform itself or of other profiles. This ensures maximum flexibility in defining and releasing a new profile or an updated version of an existing one.
In accordance with the definition of profiles given above, a profile may end up being either a proper subset or a proper superset of the platform, or it may overlap with it to a certain extent. This flexibility guarantees that future profiles will be able to cover uses well beyond those originally envisioned by the platform specification.
As the previous paragraphs made clear, creating a new profile is a significant undertaking. The decision to create a profile should take into account its potential drawbacks, especially in terms of fragmentation and developer confusion. In general, a profile should be created only when there is a natural developer constituency and a well-understood class of applications that can benefit from it. It is also recommended that a profile cast a comprehensive net on its area of interest, to minimize the occurrence of overlapping or competing profiles. Jakarta EE platform features such as optional components and extensibility can be used by profiles to achieve a better fit to their intended target.
2.3. Application Components
The Jakarta EE runtime environment defines four application component types that a Jakarta EE product must support:
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Application clients are Java programming language programs that are typically GUI programs that execute on a desktop computer. Application clients offer a user experience similar to that of native applications and have access to all of the facilities of the Jakarta EE middle tier.
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Applets are GUI components that typically execute in a web browser, but can execute in a variety of other applications or devices that support the applet programming model. Applets can be used to provide a powerful user interface for Jakarta EE applications. (Simple HTML pages can also be used to provide a more limited user interface for Jakarta EE applications.)
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servlets, server pages, server faces applications, filters, and web event listeners typically execute in a web container and may respond to HTTP requests from web clients. Servlets, server pages, server faces applications, and filters may be used to generate HTML pages that are an application’s user interface. They may also be used to generate XML or other format data that is consumed by other application components. A special kind of servlet provides support for web services using the SOAP/HTTP protocol. Servlets, pages created with the Jakarta Server Pages technology or Jakarta Server Faces technology, web filters, and web event listeners are referred to collectively in this specification as “web components.” Web applications are composed of web components and other data such as HTML pages. Web components execute in a web container. A web server includes a web container and other protocol support, security support, and so on, as required by Jakarta EE specifications.
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Jakarta Enterprise Beans components execute in a managed environment that supports transactions. Enterprise beans typically contain the business logic for a Jakarta EE application. Enterprise beans may directly provide web services using the SOAP/HTTP protocol.
2.3.1. Jakarta EE Server Support for Application Components
The Jakarta EE servers provide deployment, management, and execution support for conforming application components. Application components can be divided into three categories according to their dependence on a Jakarta EE server:
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Components that are deployed, managed, and executed on a Jakarta EE server. These components include web components and Jakarta Enterprise Beans components. See the separate specifications for these components.
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Components that are deployed and managed on a Jakarta EE server, but are loaded to and executed on a client machine. These components include web resources such as HTML pages and applets embedded in HTML pages.
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Components whose deployment and management is not completely defined by this specification. Application Clients fall into this category. Future versions of this specification may more fully define deployment and management of Application Clients. See Application Clients,” for a description of Application Clients.
2.4. Containers
Containers provide the runtime support for Jakarta EE application components. Containers provide a federated view of the underlying Jakarta EE APIs to the application components. Jakarta EE application components never interact directly with other Jakarta EE application components. They use the protocols and methods of the container for interacting with each other and with platform services. Interposing a container between the application components and the Jakarta EE services allows the container to transparently inject the services required by the component, such as declarative transaction management, security checks, resource pooling, and state management.
A typical Jakarta EE product will provide a container for each application component type: application client container, applet container, web component container, and enterprise bean container.
2.4.1. Container Requirements
This specification requires that containers provide a Java Compatible™ runtime environment, as defined by the Java Platform, Standard Edition, v8 specification (Java SE). The applet container may use the Java Plugin product to provide this environment, or it may provide it natively. The use of applet containers providing JDK™ 1.1 APIs is outside the scope of this specification.
The container tools must understand the file formats for the packaging of application components for deployment.
The containers are implemented by a Jakarta EE Product Provider. See the description of the Product Provider role in Jakarta EE Product Provider”.
This specification defines a set of standard services that each Jakarta EE product must support. These standard services are described below. The Jakarta EE containers provide the APIs that application components use to access these services. This specification also describes standard ways to extend Jakarta EE services with connectors to other non-Jakarta EE application systems, such as mainframe systems and ERP systems.
2.4.2. Jakarta EE Servers
Underlying a Jakarta EE container is the server of which it is a part. A Jakarta EE Product Provider typically implements the Jakarta EE server-side functionality using an existing transaction processing infrastructure in combination with Java Platform, Standard Edition (Java SE) technology. The Jakarta EE client functionality is typically built on Java SE technology.
2.5. Resource Adapters
A resource adapter is a system-level software component that typically implements network connectivity to an external resource manager. A resource adapter can extend the functionality of the Jakarta EE platform either by implementing one of the Java SE service APIs (such as a JDBC™ driver), or by defining and implementing a resource adapter for a connector to an external application system. Resource adapters may also provide services that are entirely local, perhaps interacting with native resources. Resource adapters interface with the Jakarta EE platform through the Jakarta EE service provider interfaces (Jakarta EE SPI). A resource adapter that uses the Jakarta EE SPIs to attach to the Jakarta EE platform will be able to work with all Jakarta EE products.
2.6. Database
The Jakarta EE platform requires a database, accessible through the JDBC API, for the storage of business data. The database is accessible from web components, enterprise beans, and application client components. The database need not be accessible from applets. The Jakarta EE Product Provider must also provide a preconfigured, default data source for use by the application in accessing this database. See Default Data Source”.
2.7. Jakarta EE Standard Services
The Jakarta EE standard services include the following (specified in more detail later in this document). Some of these standard services are actually provided by Java SE.
2.7.1. HTTP
The HTTP client-side API is defined by the java.net package. The HTTP server-side API is defined by the Jakarta Servlet, Jakarta Server Pages, and Jakarta Server Faces interfaces and by the web services support that is a part of the Jakarta EE platform.
2.7.2. HTTPS
Use of the HTTP protocol over the SSL protocol is supported by the same client and server APIs as HTTP.
2.7.3. Jakarta Transaction API (JTA)
The Jakarta Transactions consists of two parts:
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An application-level demarcation interface that is used by the container and application components to demarcate transaction boundaries.
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An interface between the transaction manager and a resource manager used at the Jakarta EE SPI level.
2.7.4. RMI-IIOP (Proposed Optional)
The RMI-IIOP subsystem is composed of APIs that allow for the use of RMI-style programming that is independent of the underlying protocol, as well as an implementation of those APIs that supports both the Java SE native RMI protocol (JRMP) and the CORBA IIOP protocol. Jakarta EE applications can use RMI-IIOP, with IIOP protocol support, to access CORBA services that are compatible with the RMI programming restrictions (see the RMI-IIOP specification for details). Such CORBA services would typically be defined by components that live outside of a Jakarta EE product, usually in a legacy system. Only Jakarta EE application clients are required to be able to define their own CORBA services directly, using the RMI-IIOP APIs. Typically such CORBA objects would be used for callbacks when accessing other CORBA objects.
Jakarta EE products must be capable of exporting Jakarta Enterprise Beans components using the IIOP protocol and accessing enterprise beans using the IIOP protocol, as specified in the Jakarta Enterprise Beans specification. The ability to use the IIOP protocol is required to enable interoperability between Jakarta EE products, however a Jakarta EE product may also use other protocols. Requirements for use of the RMI-IIOP APIs when accessing Jakarta Enterprise Beans components have been relaxed as of EJB 3.0. See the Jakarta Enterprise Beans specification for details.
Support for CORBA, including use of IIOP and Java IDL, is Proposed Optional as of Jakarta EE 8. See Pruned Java Technologies.”
2.7.5. Java IDL (Proposed Optional)
Java IDL allows Jakarta EE application components to invoke external CORBA objects using the IIOP protocol. These CORBA objects may be written in any language and typically live outside a Jakarta EE product. Jakarta EE applications may use Java IDL to act as clients of CORBA services, but only Jakarta EE application clients are required to be allowed to use Java IDL directly to present CORBA services themselves.
2.7.6. JDBC™ API
The JDBC API is the API for connectivity with relational database systems. The JDBC API has two parts: an application-level interface used by the application components to access a database, and a service provider interface to attach a JDBC driver to the Jakarta EE platform. Support for the service provider interface is not required in Jakarta EE products. Instead, JDBC drivers should be packaged as resource adapters that use the facilities of the Connector API to interface with a Jakarta EE product. The JDBC API is included in Java SE, but this specification includes additional requirements on JDBC device drivers.
2.7.7. Jakarta Persistence API
Jakarta Persistence is the standard API for the management of persistence and object/relational mapping. It provides an object/relational mapping facility for application developers using a Java domain model to manage a relational database. Jakarta Persistence is required to be supported in Jakarta EE. It can also be used in Java SE environments.
2.7.8. Jakarta™ Messaging
Jakarta Messaging is a standard API for messaging that supports reliable point-to-point messaging as well as the publish-subscribe model. This specification requires a Jakarta Messaging provider that implements both point-to-point messaging as well as publish-subscribe messaging. The Jakarta EE Product Provider must also provide a preconfigured, default Jakarta Messaging connection factory for use by the application in accessing this JMS provider. See Default Jakarta Messaging Connection Factory”.
2.7.9. Java Naming and Directory Interface™ (JNDI)
The JNDI API is the standard API for naming and directory access. The JNDI API has two parts: an application-level interface used by the application components to access naming and directory services and a service provider interface to attach a provider of a naming and directory service. The JNDI API is included in Java SE, but this specification defines additional requirements.
2.7.10. Jakarta™ Mail
Many Internet applications require the ability to send email notifications, so the Jakarta EE platform includes the Jakarta Mail API along with a Jakarta Mail service provider that allows an application component to send Internet mail. The Jakarta Mail API has two parts: an application-level interface used by the application components to send mail, and a service provider interface used at the Jakarta EE SPI level.
2.7.11. JavaBeans™ Activation Framework (JAF)
The JAF API provides a framework for handling data in different MIME types, originating in different formats and locations. The JavaMail API makes use of the JAF API. The JAF API is included in Java SE and so is available to Jakarta EE applications.
2.7.12. XML Processing
The Java™ API for XML Processing (JAXP) provides support for the industry standard SAX and DOM APIs for parsing XML documents, as well as support for XSLT transform engines. The Streaming API for XML (StAX) provides a pull-parsing API for XML. The JAXP and StAX APIs are included in Java SE and so are available to Jakarta EE applications.
2.7.13. Jakarta Connector Architecture
The Connector architecture is a Jakarta EE SPI that allows resource adapters that support access to Enterprise Information Systems to be plugged in to any Jakarta EE product. The Connector architecture defines a standard set of system-level contracts between a Jakarta EE server and a resource adapter. The standard contracts include:
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A connection management contract that lets a Jakarta EE server pool connections to an underlying EIS, and lets application components connect to an EIS. This leads to a scalable application environment that can support a large number of clients requiring access to EIS systems.
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A transaction management contract between the transaction manager and an EIS that supports transactional access to EIS resource managers. This contract lets a Jakarta EE server use a transaction manager to manage transactions across multiple resource managers. This contract also supports transactions that are managed internal to an EIS resource manager without the necessity of involving an external transaction manager.
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A security contract that enables secure access to an EIS. This contract provides support for a secure application environment, which reduces security threats to the EIS and protects valuable information resources managed by the EIS.
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A thread management contract that allows a resource adapter to delegate work to other threads and allows the application server to manage a pool of threads. The resource adapter can control the security context and transaction context used by the worker thread.
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A contract that allows a resource adapter to deliver messages to message driven beans independent of the specific messaging style, messaging semantics, and messaging infrastructure used to deliver messages. This contract also serves as the standard message provider pluggability contract that allows a message provider to be plugged into any Jakarta EE server via a resource adapter.
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A contract that allows a resource adapter to propagate an imported transaction context to the Jakarta EE server such that its interactions with the server and any application components are part of the imported transaction. This contract preserves the ACID (atomicity, consistency, isolation, durability) properties of the imported transaction.
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An optional contract providing a generic command interface between an application program and a resource adapter.
2.7.14. Security Services
The Java™ Authentication and Authorization Service (JAAS) enables services to authenticate and enforce access controls upon users. It implements a Java technology version of the standard Pluggable Authentication Module (PAM) framework and supports user-based authorization. Jakarta™ Authorization defines a contract between a Jakarta EE application server and an authorization service provider, allowing custom authorization service providers to be plugged into any Jakarta EE product. Jakarta™ Authentication defines an SPI by which authentication providers implementing message authentication mechanisms may be integrated in client or server message processing containers or runtimes. Jakarta Security leverages Jakarta Authentication, but provides an easier to use SPI for authentication of users of web applications and defines identity store APIs for authentication and authorization.
2.7.15. Web Services
Jakarta EE provides full support for both clients of web services as well as web service endpoints. Several Java technologies work together to provide support for web services. JAX-WS and Jakarta XML-based RPC both provide support for web service calls using the SOAP/HTTP protocol. JAX-WS, which is included in Java SE, is the primary API for web services and is a follow-on to Jakarta XML-based RPC. JAX-WS offers extensive web services functionality, with support for multiple bindings/protocols. JAX-WS and Jakarta XML-based RPC are fully interoperable when using the SOAP 1.1 over HTTP protocol as constrained by the WS-I Basic Profile specification. Support for Jakarta XML-based RPC has been made optional as of Java EE 7. See Pruned Java Technologies”.
JAX-WS and the Java Architecture for XML Binding (JAXB) define the mapping between Java classes and XML as used in SOAP calls, and provide support for 100% of XML Schema. JAXB is included in Java SE. The SOAP with Attachments API for Java (SAAJ), which is also included in Java SE, provides support for manipulating low level SOAP messages. The Web Services for Jakarta EE specification fully defines the deployment of web service clients and web service endpoints in Java EE, as well as the implementation of web service endpoints using enterprise beans. The Web Services Metadata specification defines Java language annotations that make it easier to develop web services. The Jakarta XML Registries provides client access to XML registry servers. Support for JAXR has been made optional as of Java EE 7. See Pruned Java Technologies”.
Jakarta JSON Processing provides a convenient way to process (parse, generate, transform, and query) JSON text. Jakarta JSON Binding provides a convenient way to convert between JSON text and Java objects. Jakarta WebSocket is a standard API for creating WebSocket applications.
Jakarta RESTful Web Services provides support for web services using the REST style. RESTful web services better match the design style of the web and are often easier to access using a wide variety of programming languages. Jakarta RESTful Web Services provides a simple high-level API for writing such web services as well as a low-level API that can be used to control the details of the web service interaction.
2.7.16. Jakarta Concurrency
Jakarta Concurrency is a standard API for providing asynchronous capabilities to Jakarta EE application components through the following types of objects: managed executor service, managed scheduled executor service, managed thread factory, and context service.
2.7.17. Jakarta Batch
The Jakarta Batch API (Batch) provides a programming model for batch applications and a runtime for scheduling and executing jobs.
2.7.18. Jakarta Management
The Jakarta Management Specification defines APIs for managing Jakarta EE servers using a special management enterprise bean. The Java™ Management Extensions (JMX) API is also used to provide some management support.
2.7.19. Jakarta Deployment
The Jakarta Deployment Specification defines a contract between deployment tools and Jakarta EE products. The Jakarta EE products provide plug-in components that run in the deployment tool and allow the deployment tool to deploy applications into the Jakarta EE product. The deployment tool provides services used by these plug-in components. Support for the Deployment Specification has been made optional as of Java EE 7. See Pruned Jakarta Technologies.”
2.8. Interoperability
Many of the APIs described above provide interoperability with components that are not a part of the Jakarta EE platform, such as external web or CORBA services.
Jakarta EE Interoperability illustrates the interoperability facilities of the Jakarta EE platform. (The directions of the arrows indicate the client/server relationships of the components.)
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2.9. Flexibility of Product Requirements
This specification doesn’t require that a Jakarta EE product be implemented by a single program, a single server, or even a single machine. In general, this specification doesn’t describe the partitioning of services or functions between machines, servers, or processes. As long as the requirements in this specification are met, Jakarta EE Product Providers can partition the functionality however they see fit. A Jakarta EE product must be able to deploy application components that execute with the semantics described by this specification.
A typical low end Jakarta EE product will support applets using the Java Plugin in one of the popular browsers, application clients each in their own Java virtual machine, and will provide a single server that supports both web components and enterprise beans. A high end Jakarta EE product might split the server components into multiple servers, each of which can be distributed and load-balanced across a collection of machines. While such machines might exist on-site in an enterprise, they might also reside, for example, in a public cloud. This specification does not prescribe or preclude any of these configurations.
A wide variety of Jakarta EE product configurations and implementations, all of which meet the requirements of this specification, are possible. A portable Jakarta EE application will function correctly when successfully deployed in any of these products.
2.10. Jakarta EE Product Packaging
This specification doesn’t include requirements for the packaging of a Jakarta EE product. A Jakarta EE product might be provided on distribution media, for download on the web, or as a service available only on the web, for example. A Jakarta EE product must include implementations of all the APIs required by this specification. These implementations might depend on other software or services not included in the Jakarta EE product. The customer may be required to combine or configure the product with other software or services that are necessary to meet the requirements of this specification. The documentation for the Jakarta EE product must fully describe all the required software and configuration.
For example, a Jakarta EE product might depend on a database server, a naming service, a mail service, and/or a messaging service. All configurations in which the product is defined to operate must include all the software and services necessary to meet the requirements of this specification.
Whether these services are available (running, accessible on the network, properly configured, operating correctly, etc.) may be controlled independently of the Jakarta EE product — they may be unavailable when the Jakarta EE server is started, or they may fail while the Jakarta EE server is running. This specification does not require the Jakarta EE product to assure the availability of these services. However, if such a service is needed to meet the requirements of this specification, the Jakarta EE product must ensure that the service has been configured for use and will be usable when it is available.
For example, this specification requires that applications can use a database. If the Jakarta EE product requires a database server to be separately installed, and requires the Jakarta EE product to be configured to use that database, such configuration must be done before applications are deployed. This ensures that the operational environment of applications includes all the required services.
2.11. Jakarta EE Product Extensions
This specification describes a minimum set of facilities available to all Jakarta EE products. A Jakarta EE profile may include some or all of these facilities, as described in Profiles”. Products implementing the full Jakarta EE platform must provide all of them (see Full Jakarta EE Product Requirements”). Most Jakarta EE products will provide facilities beyond the minimum required by this specification. This specification includes only a few limits to the ability of a product to provide extensions. In particular, it includes the same restrictions as Java SE on extensions to Java APIs. A Jakarta EE product must not add classes to the Java programming language packages included in this specification, and must not add methods or otherwise alter the signatures of the specified classes.
However, many other extensions are allowed. A Jakarta EE product may provide additional Java APIs, either other Java optional packages or other (appropriately named) packages. A Jakarta EE product may include support for additional protocols or services not specified here. A Jakarta EE product may support applications written in other languages, or may support connectivity to other platforms or applications.
Of course, portable applications will not make use of any platform extensions. Applications that do make use of facilities not required by this specification will be less portable. Depending on the facility used, the loss of portability may be minor or it may be significant.
We expect Jakarta EE products to vary widely and compete vigorously on various aspects of quality of service. Products will provide different levels of performance, scalability, robustness, availability, and security. In some cases this specification requires minimum levels of service. Future versions of this specification may allow applications to describe their requirements in these areas.
2.12. Platform Roles
This section describes typical Java Platform, Enterprise Edition roles. In an actual instance, an organization may divide role functionality differently to match that organization’s application development and deployment workflow.
The roles are described in greater detail in later sections of this specification.
2.12.1. Jakarta EE Product Provider
A Jakarta EE Product Provider is the implementor and supplier of a Jakarta EE product that includes the component containers, Jakarta EE platform APIs, and other features defined in this specification. A Jakarta EE Product Provider is typically an application server vendor, a web server vendor, a database system vendor, or an operating system vendor. A Jakarta EE Product Provider must make available the Jakarta EE APIs to the application components through containers. A Product Provider frequently bases their implementation on an existing infrastructure.
A Jakarta EE Product Provider must provide the mapping of the application components to the network protocols as specified by this specification. A Jakarta EE product is free to implement interfaces that are not specified by this specification in an implementation-specific way.
A Jakarta EE Product Provider must provide application deployment and management tools. Deployment tools enable a Deployer (see Deployer”) to deploy application components on the Jakarta EE product. Management tools allow a System Administrator (see System Administrator”) to manage the Jakarta EE product and the applications deployed on the Jakarta EE product. The form of these tools is not prescribed by this specification.
2.12.2. Application Component Provider
There are multiple roles for Application Component Providers, including, for example, HTML document designers, document programmers, and enterprise bean developers. These roles use tools to produce Jakarta EE applications and components.
2.12.3. Application Assembler
The Application Assembler takes a set of components developed by Application Component Providers and assembles them into a complete Jakarta EE application delivered in the form of an Enterprise Archive ( .ear ) file. The Application Assembler will generally use GUI tools provided by either a Platform Provider or Tool Provider. The Application Assembler is responsible for providing assembly instructions describing external dependencies of the application that the Deployer must resolve in the deployment process.
2.12.4. Deployer
The Deployer is responsible for deploying application clients, web applications, and Enterprise JavaBeans components into a specific operational environment. The Deployer uses tools supplied by the Jakarta EE Product Provider to carry out deployment tasks. Deployment is typically a three-stage process:
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During Installation the Deployer moves application media to the server, generates the additional container-specific classes and interfaces that enable the container to manage the application components at runtime, and installs application components, and additional classes and interfaces, into the appropriate Jakarta EE containers.
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During Configuration, external dependencies declared by the Application Component Provider are resolved and application assembly instructions defined by the Application Assembler are followed. For example, the Deployer is responsible for mapping security roles defined by the Application Assembler onto user groups and accounts that exist in the target operational environment.
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Finally, the Deployer starts up Execution of the newly installed and configured application.
In some cases, a specially qualified Deployer may customize the business logic of the application’s components at deployment time. For example, using tools provided with a Jakarta EE product, the Deployer may provide simple application code that wraps an enterprise bean’s business methods, or customizes the appearance of a Jakarta Server Pages or Jakarta Server Faces page.
The Deployer’s output is web applications, enterprise beans, applets, and application clients that have been customized for the target operational environment and are deployed in a specific Jakarta EE container.
For example, in the case of cloud deployments, the Deployer would be responsible for configuring the application to run in the cloud environment. The Deployer would install the application into the cloud environment, configure its external dependencies, and might handle aspects of provisioning its required resources.
2.12.5. System Administrator
The System Administrator is responsible for the configuration and administration of the enterprise’s computing and networking infrastructure. The System Administrator is also responsible for overseeing the runtime well-being of the deployed Jakarta EE applications. The System Administrator typically uses runtime monitoring and management tools provided by the Jakarta EE Product Provider to accomplish these tasks.
For example, in a cloud scenario, the System Administrator would be responsible for installing, configuring, managing, and maintaining the cloud environment, including the resources that are made available to applications running in the environment.
2.12.6. Tool Provider
A Tool Provider provides tools used for the development and packaging of application components. A variety of tools are anticipated, corresponding to the types of application components supported by the Jakarta EE platform. Platform independent tools can be used for all phases of development through the deployment of an application and the management and monitoring of an application server.
2.12.7. System Component Provider
A variety of system level components may be provided by System Component Providers. The Connector Architecture defines the primary APIs used to provide resource adapters of many types. These resource adapters may connect to existing enterprise information systems of many types, including databases and messaging systems. Another type of system component is an authorization policy provider as defined by the Jakarta Authorization specification.
2.13. Platform Contracts
This section describes the Jakarta EE contracts that must be fulfilled by a Jakarta EE Product Provider implementing the full Jakarta EE platform. Jakarta EE profiles may include some or all of these facilities, as described in Profiles”.
2.13.1. Jakarta EE APIs
The Jakarta EE APIs define the contract between the Jakarta EE application components and the Jakarta EE platform. The contract specifies both the runtime and deployment interfaces.
The Jakarta EE Product Provider must implement the Jakarta EE APIs in a way that supports the semantics and policies described in this specification. The Application Component Provider provides components that conform to these APIs and policies.
2.13.2. Jakarta EE Service Provider Interfaces (SPIs)
The Jakarta EE Service Provider Interfaces (SPIs) define the contract between the Jakarta EE platform and service providers that may be plugged into a Jakarta EE product. The connector APIs define service provider interfaces for integrating resource adapters with a Jakarta EE application server. Resource adapter components implementing the connector APIs are called Connectors. The Jakarta Authorization APIs define service provider interfaces for integrating security authorization mechanisms with a Jakarta EE application server.
The Jakarta EE Product Provider must implement the Jakarta EE SPIs in a way that supports the semantics and policies described in this specification. A provider of Service Provider components (for example, a Connector Provider) should provide components that conform to these SPIs and policies.
2.13.3. Network Protocols
This specification defines the mapping of application components to industry-standard network protocols. The mapping allows client access to the application components from systems that have not installed Jakarta EE product technology. See Interoperability,” for details on the network protocol support required for interoperability.
The Jakarta EE Product Provider is required to publish the installed application components on the industry-standard protocols. This specification defines the mapping of servlets and server pages to the HTTP and HTTPS protocols, and the mapping of Jakarta Enterprise Beans components to IIOP and SOAP protocols.
2.13.4. Deployment Descriptors and Annotations
Deployment descriptors and Java language annotations are used to communicate the needs of application components to the Deployer. The deployment descriptor and class file annotations are a contract between the Application Component Provider or Assembler and the Deployer. The Application Component Provider or Assembler is required to specify the application component’s external resource requirements, security requirements, environment parameters, and so forth in the component’s deployment descriptor or through class file annotations. The Jakarta EE Product Provider is required to provide a deployment tool that interprets the Jakarta EE deployment descriptors and class file annotations and allows the Deployer to map the application component’s requirements to the capabilities of a specific Jakarta EE product and environment.
2.14. Changes in J2EE 1.3
The J2EE 1.3 specification extends the J2EE platform with additional enterprise integration facilities. The Connector API supports integration with external enterprise information systems. A JMS provider is now required. The JAXP API provides support for processing XML documents. The JAAS API provides security support for the Connector API. The EJB specification now requires support for interoperability using the IIOP protocol.
Significant changes have been made to the EJB specification. The EJB specification has a new container-managed persistence model, support for message driven beans, and support for local enterprise beans.
Other existing J2EE APIs have been updated as well. See the individual API specifications for details. Finally, J2EE 1.3 requires support for J2SE 1.3.
2.15. Changes in J2EE 1.4
The primary focus of J2EE 1.4 is support for web services. The JAX-RPC and SAAJ APIs provide the basic web services interoperability support. The Web Services for J2EE specification describes the packaging and deployment requirements for J2EE applications that provide and use web services. The EJB specification was also extended to support implementing web services using stateless session beans. The JAXR API supports access to registries and repositories.
Several other APIs have been added to J2EE 1.4. The J2EE Management and J2EE Deployment APIs enable enhanced tool support for J2EE products. The JMX API supports the J2EE Management API. The J2EE Authorization Contract for Containers provides an SPI for security providers.
Many of the existing J2EE APIs have been enhanced in J2EE 1.4. J2EE 1.4 builds on J2SE 1.4. The JSP specification has been enhanced to simplify the development of web applications. The Connector API now supports integration with asynchronous messaging systems, including the ability to plug in JMS providers.
Changes in this J2EE platform specification include support for deploying class libraries independently of any application and the conversion of deployment descriptor DTDs to XML Schemas.
Other J2EE APIs have been enhanced as well. For additional details, see each of the referenced specifications.
2.16. Changes in Java EE 5
With this release, the platform has a new name – Java Platform, Enterprise Edition, or Java EE for short. This new name gets rid of the confusing “2” while emphasizing even in the short name that this is a Java platform. Previous versions are still referred to using the old name “J2EE”.
The focus of Java EE 5 is ease of development. To simplify the development process for programmers just starting with Java EE, or developing small to medium applications, Java EE 5 makes extensive use of Java language annotations, which were introduced by J2SE 5.0. Annotations reduce or eliminate the need to deal with Java EE deployment descriptors in many cases. Even large applications can benefit from the simplifications provided by annotations.
One of the major uses of annotations is to specify injection of resources and other dependencies into Java EE components. Injection augments the existing JNDI lookup capability to provide a new simplified model for applications to gain access to the resources needed from the operational environment. Injection also works with deployment descriptors to allow the deployer to customize or override resource settings specified in the application’s source code.
The use of annotations is made even more effective by providing better defaults. Better default behavior and better default configuration allows most applications to get the behavior they want most of the time, without the use of either annotations or deployment descriptors in many cases. When the default is not what the application wants, a simple annotation can be used to specify the required behavior or configuration.
The combination of annotations and better defaults has greatly simplified the development of applications using Enterprise JavaBeans technology and applications defining or using web services. Enterprise beans are now dramatically simpler to develop. Web services are much easier to develop using the annotations defined by the Web Services Metadata specification.
The area of web services continues to evolve at a rapid pace. To provide the latest web services support, the JAX-RPC technology has evolved into the JAX-WS technology, which makes heavy use of the JAXB technology to bind Java objects to XML data. Both JAX-WS and JAXB are new to this version of the platform.
Major additions to Java EE 5 include the JSTL and JSF technologies that simplify development of web applications, and the Java Persistence API developed by the EJB 3.0 expert group, which greatly simplifies mapping Java objects to databases.
Minor additions include the StAX API for XML parsing. Most APIs from previous versions have been updated with small to medium improvements.
2.17. Changes in Java EE 6
Java EE 6 continues the “ease of development” focus of Java EE 5.
One of the major improvements introduced in Java EE 6 is the Contexts and Dependency Injection (CDI) technology, which provides a uniform framework for the dependency injection and lifecycle management of “managed beans”.
The Java EE 6 Managed Bean specification defines the commonalities across the spectrum of Java EE managed objects, extending from basic managed beans through EJB components.
The Bean Validation specification, introduced in this release, provides a facility for validation of managed objects. Bean Validation is integrated into the Java Persistence API, where it provides an automated facility for the validation of JPA entities.
Java EE 6 adds the JAX-RS API as a required technology of the Java EE Platform. JAX-RS is the API for the development of Web services built according to the Representational State Transfer (REST) architectural style.
Java EE 6 also introduces the Java EE Web Profile, the first new profile of the Java EE Platform.
2.18. Changes in Java EE 7
Since its inception, the Java EE platform has been targeted at offloading the developer from common infrastructure tasks through its container-based model and abstraction of resource access. In recent releases the platform has considerably simplified the APIs for access to container services while broadening the range of the services available. In this release we continue the direction of improved simplification, while extending the range of the Java EE platform to encompass emerging technologies in the web space.
The Java EE 7 platform adds first-class support for recent developments in web standards, including Web Sockets and JSON, which provide the underpinnings for HTML 5 support in Java EE. Java EE 7 also adds a modern HTTP client API as defined by JAX-RS 2.0.
Also new in the Java EE 7 platform is the Batch API, which provides a programming model for batch applications and a runtime for scheduling and executing jobs, and the Concurrency Utilities API, which provides asynchronous capabilities by means of managed executor service, managed scheduled executor service, managed thread factory, and context service.
The CDI dependency injection facility introduced in Java EE 6 is enhanced as well as more broadly utilized by the Java EE 7 platform technologies, and the managed bean model is further aligned to remove inconsistencies among Java EE component classes in aspects of CDI injection and interceptor support. The declarative transaction functionality introduced by EJB is been made available in a more general way through CDI interceptors, so that it may be leveraged by other managed beans. The Bean Validation facility is extended to the automatic validation of method invocations and likewise made available via CDI interceptors.
Java EE 7 also continues the "ease of development" focus of Java EE 5 and Java EE 6. Most notably, Java EE 7 includes a revised and greatly simplified JMS 2.0 API. Ease of development encompasses ease of configuration as well. To that end, Java EE 7 broadens the resource definition facilities introduced in Java EE 6 to encompass more of the standard platform resource types, and also provides default database and JMS connection factory resources. It also improves the configuration of application security, including new descriptors for security permissions. Java EE 7 further simplifies the platform by making optional the technologies that were identified as candidates for pruning in Java EE 6, namely: EJB Entity Beans, JAX-RPC 1.1, JAXR 1.0, and JSR-88 1.2.
Finally, Java EE 7 lays groundwork for enhancements to the platform for use in cloud environments in a future release. Such features include resource definition metadata, improved security configuration, and support for database schema generation via the Java Persistence API.
2.19. Changes in Java EE 8
Java EE 8 continues the focus on modern web applications of Java EE 7 and broadening the range of such applications. Java EE 8 introduces the JSON Binding API (JSON-B) for mapping between JSON text and Java objects, building on the JSON Processing API (JSON-P) introduced in Java EE 7. The JSON Processing API itself is updated to reflect additional JSON standards. Servlet undergoes major enhancement with the addition of support for the new HTTP/2 protocol. JAX-RS adds support for server-sent events and, building on concurrency facilities added in Java SE 8, a reactive client API. The new Java EE Security API provides enhanced support for authentication and authorization in web modules, and also introduces APIs for access to identity stores. The Bean Validation facility is updated to reflect enhancements made in Java SE 8 and to extend the range of validated objects. While the focus of CDI in this release is to extend its scope beyond Java EE with the introduction of a bootstrapping API, CDI also includes enhancements for event processing and alignment on Java SE 8 features.
2.20. Changes in Jakarta EE 8
Jakarta EE 8 is the migration of Java EE 8 from the JCP to the Eclipse Foundation. Reference the "Specification Comparison" and “Revision History" appendices for more information.
3. Security
This chapter describes the security requirements for the Jakarta™ Enterprise Edition (Jakarta EE) that must be satisfied by Jakarta EE products.
In addition to the Jakarta EE requirements, each Jakarta EE Product Provider will determine the level of security and security assurances that will be provided by their implementation.
3.1. Introduction
Almost every enterprise has security requirements and specific mechanisms and infrastructure to meet them. Sensitive resources that can be accessed by many users or that often traverse unprotected open networks (such as the Internet) need to be protected.
Although the quality assurances and implementation details may vary, they all share some of the following characteristics:
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Authentication : The means by which communicating entities (for example, client and server) prove to one another that they are acting on behalf of specific identities that are authorized for access.
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Access control for resources : The means by which interactions with resources are limited to collections of users or programs for the purpose of enforcing integrity, confidentiality, or availability constraints.
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Data integrity : The means used to prove that information has not been modified by a third party (some entity other than the source of the information). For example, a recipient of data sent over an open network must be able to detect and discard messages that were modified after they were sent.
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Confidentiality or Data Privacy : The means used to ensure that information is made available only to users who are authorized to access it.
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Non-repudiation : The means used to prove that a user performed some action such that the user cannot reasonably deny having done so.
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Auditing : The means used to capture a tamper-resistant record of security related events for the purpose of being able to evaluate the effectiveness of security policies and mechanisms.
This chapter specifies how Jakarta EE platform requirements address security requirements, and identifies requirements that may be addressed by Jakarta EE Product Providers. Finally, issues being considered for future versions of this specification are briefly mentioned in Future Directions.
3.2. A Simple Example
The security behavior of a Jakarta EE environment may be better understood by examining what happens in a simple application with a web client, a JSP user interface, and enterprise bean business logic. (The example is not meant to specify requirements.)
In this example, the web client relies on the web server to act as its authentication proxy by collecting user authentication data from the client and using it to establish an authenticated session.
- Initial Request
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The web client requests the main application URL, shown in Initial Request .
Since the client has not yet authenticated itself to the application environment, the server responsible for delivering the web portion of the application (hereafter referred to as “web server”) detects this and invokes the appropriate authentication mechanism for this resource.
- Initial Authentication
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The web server returns a form that the web client uses to collect authentication data (for example, username and password) from the user. The web client forwards the authentication data to the web server, where it is validated by the web server, as shown in Initial Authentication .
The validation mechanism may be local to the server, or it may leverage the underlying security services. On the basis of the validation, the web server sets a credential for the user.
- URL Authorization
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The credential is used for future determinations of whether the user is authorized to access restricted resources it may request. The web server consults the security policy (derived from the deployment descriptor) associated with the web resource to determine the security roles that are permitted access to the resource. The web container then tests the user’s credential against each role to determine if it can map the user to the role. URL Authorization shows this process.
The web server’s evaluation stops with an “is authorized” outcome when the web server is able to map the user to a role. A “not authorized” outcome is reached if the web server is unable to map the user to any of the permitted roles.
- Fulfilling the Original Request
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If the user is authorized, the web server returns the result of the original URLrequest, as shown in Fulfilling the Original Request .
In our example, the response URL of a JSP page is returned, enabling the user to post form data that needs to be handled by the business logic component of the application.
- Invoking Enterprise Bean Business Methods
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The JSP page performs the remote method call to the enterprise bean, using the user’s credential to establish a secure association between the JSP page and the enterprise bean (as shown in Invoking an Enterprise Bean Business Method ). The association is implemented as two related security contexts, one in the web server and one in the Jakarta Enterprise Beans container.
The Jakarta Enterprise Beans container is responsible for enforcing access control on the enterprise bean method. It consults the security policy (derived from the deployment descriptor) associated with the enterprise bean to determine the security roles that are permitted access to the method. For each role, the Jakarta Enterprise Beans container uses the security context associated with the call to determine if it can map the caller to the role.
The container’s evaluation stops with an “is authorized” outcome when the container is able to map the caller’s credential to a role. A “not authorized” outcome is reached if the container is unable to map the caller to any of the permitted roles. A “not authorized” result causes an exception to be thrown by the container, and propagated back to the calling JSP page.
If the call “is authorized”, the container dispatches control to the enterprise bean method. The result of the bean’s execution of the call is returned to the JSP, and ultimately to the user by the web server and the web client.
3.3. Security Architecture
This section describes the Jakarta EE security architecture on which the security requirements defined by this specification are based.
3.3.1. Goals
The following are goals for the Jakarta EE security architecture:
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Portability: The Jakarta EE security architecture must support the Write Once, Run Anywhere™ application property.
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Transparency: Application Component Providers should not have to know anything about security to write an application.
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Isolation: The Jakarta EE platform should be able to perform authentication and access control according to instructions established by the Deployer using deployment attributes, and managed by the System Administrator.
Note that divorcing the application from responsibility for security ensures greater portability of Jakarta EE applications.
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Extensibility: The use of platform services by security-aware applications must not compromise application portability.
This specification provides APIs in the component programming model for interacting with container/server security information. Applications that restrict their interactions to the provided APIs will retain portability.
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Flexibility: The security mechanisms and declarations used by applications under this specification should not impose a particular security policy, but facilitate the implementation of security policies specific to the particular Jakarta EE installation or application.
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Abstraction: An application component’s security requirements will be logically specified using Java language annotations or deployment descriptors. Java language annotations or deployment descriptors will specify how security roles and access requirements are to be mapped into environment-specific security roles, users, and policies. A Deployer may choose to modify the security properties in ways consistent with the deployment environment. The annotations or deployment descriptor should document which security properties can be modified and which cannot.
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Independence: Required security behaviors and deployment contracts should be implementable using a variety of popular security technologies.
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Compatibility testing: The Jakarta EE security requirements architecture must be expressed in a manner that allows for an unambiguous determination of whether or not an implementation is compatible.
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Secure interoperability: Application components executing in a Jakarta EE product must be able to invoke services provided in a Jakarta EE product from a different vendor, whether with the same or a different security policy. The services may be provided by web components or enterprise beans.
3.3.2. Non Goals
The following are not goals for the Jakarta EE security architecture:
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This specification does not dictate a specific security policy. Security policies for applications and for enterprise information systems vary for many reasons unconnected with this specification. Product Providers can provide the technology needed to implement and administer desired security policies while adhering to the requirements of this specification.
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This specification does not mandate a specific security technology, such as Kerberos, PK, NIS+, or NTLM.
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This specification does not require that the Jakarta EE security behaviors be universally implementable using any or all security technologies.
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This specification does not provide any warranty or assurance of the effective security of a Jakarta EE product.
3.3.3. Terminology
This section introduces the terminology that is used to describe the security requirements of the Jakarta EE platform.
- Principal
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A principal is an entity that can be authenticated by an authentication protocol in a security service that is deployed in an enterprise. A principal is identified using a principal name and authenticated using authentication data. The content and format of the principal name and the authentication data can vary depending upon the authentication protocol.
- Security Policy Domain
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A security policy domain, also referred to as a security domain, is a scope over which a common security policy is defined and enforced by the security administrator of the security service.
A security policy domain is also sometimes referred to as a realm. This specification uses the security policy domain, or security domain, terminology.
- Security Technology Domain
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A security technology domain is the scope over which the same security mechanism (for example Kerberos) is used to enforce a security policy.
A single security technology domain may include multiple security policy domains, for example.
- Security Attributes
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A set of security attributes is associated with every principal. The security attributes have many uses (for example, access to protected resources and auditing of users). Security attributes can be associated with a principal by an authentication protocol and/or by the Jakarta EE Product Provider.
The Jakarta EE platform does not specify what security attributes are associated with a principal.
- Credential
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A credential contains or references information (security attributes) used to authenticate a principal for Jakarta EE product services. A principal acquires a credential upon authentication, or from another principal that allows its credential to be used (delegation).
This specification does not specify the contents or the format of a credential. The contents and format of a credential can vary widely.
3.3.4. Container Based Security
Security for components is provided by their containers in order to achieve the goals for security specified above in a Jakarta EE environment. A container provides two kinds of security (discussed in the following sections):
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Declarative security
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Programmatic security
3.3.4.1. Declarative Security
Declarative security refers to the means of expressing an application’s security structure, including security roles, access control, and authentication requirements in non-programmatic form. Java language annotations and the deployment descriptor are the primary vehicles for declarative security in the Jakarta EE platform.
Java language annotations and the deployment descriptor are a contract between an Application Component Provider and a Deployer or Application Assembler. They can be used by an application programmer to represent an application’s security related environmental requirements. A deployment descriptor can be associated with groups of components.
A Deployer maps the declarative representation of the application’s security policy to a security structure specific to the particular environment. A Deployer uses a deployment tool to process the annotations and deployment descriptor.
At runtime, the container uses the security policy security structure derived from the declarative security information expressed in annotations and the deployment descriptor and configured by the Deployer to enforce authorization (see Authorization Model).
3.3.4.2. Programmatic Security
Programmatic security refers to security decisions made by security aware applications. Programmatic security is useful when declarative security alone is not sufficient to express the security model of the application. The API for programmatic security consists of methods of the Jakarta Security SecurityContext interface, and methods of the Jakarta Enterprise Beans EJBContext interface and the servlet HttpServletRequest interface. The methods of the Jakarta Security SecurityContext interface are intended to supersede the corresponding methods of the EJBContext and HttpServletRequest interfaces.
These methods allow components to make business logic decisions based on the security role of the caller or remote user. For example they allow the component to determine the principal name of the caller or remote user to use as a database key. (Note that the form and content of principal names will vary widely between products and enterprises, and portable components will not depend on the actual contents of a principal name. Due to principal name mapping, the same logical principal may have different names in different containers, although usually it will be possible to configure a single product to use consistent principal names. In particular, if a principal name is used as a key into a database table, and that database table is accessed from multiple components, containers, or products, the same logical principal may map to different entries in the database.)
3.3.5. Distributed Security
Some Product Providers may produce Jakarta EE products in which the containers for various component types are distributed. In a distributed environment, communication between Jakarta EE components can be subject to security attacks (for example, data modification and replay attacks).
Such threats can be countered by using a secure association to secure communications. A secure association is shared security state information that establishes the basis of a secure communication between components. Establishing a secure association could involve several steps, such as:
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Authenticating the target principal to the client and/or authenticating the client to the target principal.
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Negotiating a quality of protection, such as confidentiality or integrity.
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Setting up a security context for the association between the components.
Since a container provides security in Jakarta EE, secure associations for a component are typically established by a container. Secure associations for web access are specified here. Secure associations for access to enterprise beans are described in the Jakarta Enterprise Beans specification.
Product Providers may allow for control over the quality of protection or other aspects of secure association at deployment time. Applications can specify their requirements for access to web resources using annotations or elements in their deployment descriptor.
This specification does not define mechanisms that an Application Component Provider can use to communicate requirements for secure associations with an enterprise bean.
3.3.6. Authorization Model
The Jakarta EE authorization model is based on the concept of security roles. A security role is a logical grouping of users that is defined by an Application Component Provider or Assembler. A Deployer maps roles to security identities (for example principals, and groups) in the operational environment. Security roles are used with both declarative security and programmatic security.
Declarative authorization can be used to control access to an enterprise bean method and is specified in annotations or in the enterprise bean deployment descriptor. The RolesAllows , PermitAll , and DenyAll annotations are used to specify method permissions. An enterprise bean method can also be associated with a method-permission element in the deployment descriptor. The method-permission element contains a list of methods that can be accessed by a given security role. If the calling principal is in one of the security roles allowed access to a method, the principal is allowed to execute the method. Conversely, if the calling principal is in none of the roles, the caller is not allowed to execute the method. Access to web resources can be protected in a similar manner.
Security roles are used in the SecurityContext method isCallerInRole , the EJBContext method isCallerInRole , and the HttpServletRequest method isUserInRole . Each method returns true if the calling principal is in the specified security role.
3.3.6.1. Role Mapping
Enforcement of security constraints on web resources or enterprise beans, whether programmatic or declarative, depends upon determination of whether the principal associated with an incoming request is in a given security role. A container makes this determination based on the security attributes of the calling principal. For example,
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A Deployer may have mapped a security role to a user group in the operational environment or may depend on the default mapping of security roles to user groups as defined by the Jakarta Security specification. In this case, the user group of the calling principal is retrieved from its security attributes. The principal is in the security role if the principal’s user group matches a user group to which the security role has been mapped.
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A Deployer may have mapped a security role to a principal name in a security policy domain. In this case, the principal name of the calling principal is retrieved from its security attributes. If this principal name is the same as a principal name to which the security role was mapped, the calling principal is in the security role.
The source of security attributes may vary across implementations of the Jakarta EE platform. Security attributes may be transmitted in the calling principal’s credential or in the security context. In other cases, security attributes may be retrieved from an identity store, or from a trusted third party, such as a directory service or a security service.
3.3.7. HTTP Login Gateways
Secure interoperability between enterprise beans in different security policy domains is addressed in the Jakarta Enterprise Beans specification. In addition, a component may choose to log in to a foreign server via HTTP. An application component can be configured to use SSL mutual authentication for security when accessing a remote resource using HTTP. Applications using HTTP in this way may choose to use XML or some other structured format, rather than HTML.
We call the use of HTTP with SSL mutual authentication to access a remote service an HTTP Login Gateway. Requirements in this area are specified in Authentication by Web Clients.
3.3.8. User Authentication
User authentication is the process by which a user proves his or her identity to the system. This authenticated identity is then used to perform authorization decisions for accessing Jakarta EE application components. An end user can authenticate using either of the two supported client types:
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Web client
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Application client
3.3.8.1. Authentication by Web Clients
It is required that a web client be able to authenticate a user to a web server using any of the following mechanisms. The Deployer or System Administrator determines which method to apply to an application or to a group of applications.
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HTTP Basic Authentication
HTTP Basic Authentication is the authentication mechanism supported by the HTTP protocol. This mechanism is based on a username and password. A web server requests a web client to authenticate the user. As part of the request, the web server passes the realm in which the user is to be authenticated. The web client obtains the username and the password from the user and transmits them to the web server. The web server then authenticates the user in the specified realm (referred to as HTTP Realm in this document).
HTTP Basic Authentication is not secure. Passwords are sent in simple base64 encoding. The target server is not authenticated. Additional protection can be applied to overcome these weaknesses. The password may be protected by applying security at the transport layer (for example HTTPS) or at the network layer (for example, IPSEC or VPN).
Despite its limitations, the HTTP Basic Authentication mechanism is included in this specification because it is widely used in form based applications.
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HTTPS Client Authentication
End user authentication using HTTPS (HTTP over SSL) is a strong authentication mechanism. This mechanism requires the user to possess a Public Key Certificate (PKC). Currently, a PKC is rarely used by end users on the Internet. However, it is useful for e-commerce applications and also for a single-signon from within the browser. For these reasons, HTTPS client authentication is a required feature of the Jakarta EE platform.
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Form Based Authentication
The look and feel of a login screen cannot be varied using the web browser’s built-in authentication mechanisms. This specification introduces the ability to package standard HTML or servlet/JSP/JSF based forms for logging in, allowing customization of the user interface. The form based authentication mechanism introduced by this specification is described in the Servlet specification.
HTTP Digest Authentication is not widely supported by web browsers and hence is not required.
A web client can employ a web server as its authentication proxy. In this case, a client’s credential is established in the server, where it may be used by the server for various purposes: to perform authorization decisions, to act as the client in calls to enterprise beans, or to negotiate secure associations with resources. Current web browsers commonly rely on proxy authentication.
3.3.8.2. Web Single Signon
HTTP is a stateless protocol. However, many web applications need support for sessions that can maintain state across multiple requests from a client. Therefore, it is desirable to:
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Make login mechanisms and policies a property of the environment the web application is deployed in.
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Be able to use the same login session to represent a user to all the applications that he or she accesses.
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Require re-authentication of users only when a security policy domain boundary has been crossed.
Credentials that are acquired through a web login process are associated with a session. The container uses the credentials to establish a security context for the session. The container uses the security context to determine authorization for access to web resources and for the establishment of secure associations with other components (including enterprise beans).
3.3.8.3. Login Session
In the Jakarta EE platform, login session support is provided by a web container. When a user successfully authenticates with a web server, the container establishes a login session context for the user. The login session contains the credentials associated with the user.[1]
3.3.8.4. Authentication by Application Clients
Application clients (described in detail in Application Clients) are client programs that may interact with enterprise beans directly (that is, without the help of a web browser and without traversing a web server). Application clients may also access web resources.
Application clients, like the other Jakarta EE application component types, execute in a managed environment that is provided by an appropriate container. Application clients are expected to have access to a graphical display and input device, and are expected to communicate with a human user.
Application clients are used to authenticate end users to the Jakarta EE platform, when the users access protected web resources or enterprise beans.
3.3.9. Lazy Authentication
There is a cost associated with authentication. For example, an authentication process may require exchanging multiple messages across the network. Therefore, it is desirable to use lazy authentication, that is, to perform authentication only when it is needed. With lazy authentication, a user is not required to authenticate until there is a request to access a protected resource.
Lazy authentication can be used with first-tier clients (applets, application clients) when they request access to protected resources that require authentication. At that point the user can be asked to provide appropriate authentication data. If a user is successfully authenticated, the user is allowed to access the resource.
3.4. User Authentication Requirements
The Jakarta EE Product Provider must meet the following requirements concerning user authentication.
3.4.1. Login Sessions
All Jakarta EE web servers must maintain a login session for each web user. It must be possible for a login session to span more than one application, allowing a user to log in once and access multiple applications. The required login session support is described in the Servlet specification. This requirement of a session for each web user supports single signon.
Applications can remain independent of the details of implementing the security and maintenance of login information. The Jakarta EE Product Provider has the flexibility to choose authentication mechanisms independent of the applications secured by these mechanisms.
Lazy authentication must be supported by web servers for protected web resources. When authentication is required, one of the three required login mechanisms listed in the next section may be used.
3.4.2. Required Login Mechanisms
All Jakarta EE products are required to support three login mechanisms: HTTP basic authentication, SSL mutual authentication, and form-based login. An application is not required to use any of these mechanisms, but they are required to be available for any application’s use.
3.4.2.1. HTTP Basic Authentication
All Jakarta EE products are required to support HTTP basic authentication (RFC2068). Platform Providers are also required to support basic authentication over SSL.
3.4.2.2. SSL Mutual Authentication
TLS 1.2 and the means to perform mutual (client and server) certificate-based authentication are required by this specification.
All Jakarta EE products must also support TLS 1.1 and TLS 1.0, to ensure interoperable secure communications with clients; however, TLS 1.0 should be disabled if not needed for a given deployment, and TLS 1.1 may be disabled if not needed.
Similarly, all Jakarta EE products must support the following cipher suites, to ensure interoperable secure communications with clients:
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TLS_RSA_WITH_AES_128_CBC_SHA
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TLS_DHE_RSA_WITH_AES_128_CBC_SHA
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TLS_ECDH_RSA_WITH_AES_128_CBC_SHA
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TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA
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TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
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TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
However, it is recommended to use the strongest possible cipher suite that can be negotiated between client and server, and the above cipher suites may be disabled in favor of stronger cipher suites, if not needed for a given deployment.
Note that previous versions of this specification required support for SSL 3.0, and for the following cipher suites:
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TLS_RSA_WITH_RC4_128_MD5
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SSL_RSA_WITH_RC4_128_MD5
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TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA
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SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA
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TLS_RSA_EXPORT_WITH_RC4_40_MD5
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SSL_RSA_EXPORT_WITH_RC4_40_MD5
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TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA
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SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA
SSL 3.0 was officially deprecated by RFC 7568 in 2015, and is unsupported or disabled by default in many TLS implementations. None of the above cipher suites is currently considered secure, and may be unsupported or disabled by default. In extreme cases, it may be necessary to use SSL 3.0, or to negotiate one of the above cipher suites, in order to interoperate with an older client or a previous version of Jakarta EE. However, it is recommended to use TLS 1.0 or higher, and to negotiate a stronger cipher suite, whenever possible. SSL 3.0, and the above listed cipher suites, should be disabled if not needed for interoperability in a given deployment.
3.4.2.3. Form Based Login
The web application deployment descriptor contains an element that causes a Jakarta EE product to associate an HTML form resource (perhaps dynamically generated) with the web application. If the Deployer chooses this form of authentication (over HTTP basic, or SSL certificate based authentication), this form must be used as the user interface for login to the application.
The form based login mechanism and web application deployment descriptors are described in the Servlet specification.
3.4.3. Unauthenticated Users
Web containers are required to support access to web resources by clients that have not authenticated themselves to the container. This is the common mode of access to web resources on the Internet.
A web container reports that no user has been authenticated by returning null from the SecurityContext method getCallerPrincipal or the HttpServletRequest method getUserPrincipal . This is different than the result of the EJBContext method getCallerPrincipal . The Jakarta Enterprise Beans specification requires that the EJBContext method getCallerPrincipal always return a valid Principal object. This method can never return null . The SecurityContext method getCallerPrincipal can also be called in the Jakarta Enterprise Beans container, and still returns null for anonymous users.
In Jakarta EE products that contain both a web container and an Jakarta Enterprise Beans container, components running in a web container must be able to call enterprise beans even when no user has been authenticated in the web container. When a call is made in such a case from a component in a web container to an enterprise bean, a Jakarta EE product must provide a principal for use in the call.
A Jakarta EE product may provide a principal for use by unauthenticated callers using many approaches, including, but not limited to:
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Always use a single distinguished principal.
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Use a different distinguished principal per server, or per session, or per application.
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Allow the deployer or system administrator to choose which principal to use through the Run As capability of the web and enterprise bean containers.
This specification does not specify how a Jakarta EE product should choose a principal to represent unauthenticated users, although future versions of this specification may add requirements in this area. Note that the Jakarta Enterprise Beans specification does include requirements in this area when using the Jakarta Enterprise Beans interoperability protocol. Applications are encouraged to use the Run As capability in cases where the web component may be unauthenticated and needs to call Jakarta Enterprise Beans components.
3.4.4. Application Client User Authentication
The application client container must provide authentication of application users to satisfy the authentication and authorization constraints enforced by the enterprise bean containers and web containers. The techniques used may vary with the implementation of the application client container, and are beyond the control of the application. The application client container may integrate with a Jakarta EE product’s authentication system, to provide a single signon capability, or the container may authenticate the user when the application is started. The container may delay authentication until there is a request to access a protected resource or enterprise bean.
The container will provide an appropriate user interface for interactions with the user to gather authentication data. In addition, an application client may provide a class that implements the javax.security.auth.callback.CallbackHandler interface and specify the class name in its deployment descriptor (see Jakarta EE Application Client XML Schema for details). The Deployer may override the callback handler specified by the application and require use of the container’s default authentication user interface instead.
If use of a callback handler has been configured by the Deployer, the application client container must instantiate an object of this class and use it for all authentication interactions with the user. The application’s callback handler must support all the Callback objects specified in the javax.security.auth.callback package.
Application clients may execute in an environment controlled by a Java SE security manager and are subject to the security permissions defined in Java Platform, Standard Edition (Java SE) Requirements. Although this specification does not define the relationship between the operating system identity associated with a running application client and the authenticated user identity, support for single signon requires that the Jakarta EE product be able to relate these identities. Additional application client requirements are described in CHApter of this specification.
3.4.5. Resource Authentication Requirements
Resources within an enterprise are often deployed in security policy domains different from the security policy domain of the application component. The wide variance of authentication mechanisms used to authenticate the caller to resources leads to the requirement that a Jakarta EE product provide the means to authenticate in the security policy domain of the resource.
A Product Provider must support both of the following:
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Configured Identity. A Jakarta EE container must be able to authenticate for access to the resource using a principal and authentication data specified by a Deployer at deployment time.The authentication must not depend in any way on data provided by the application components. Providing for the confidential storage of the authentication information is the responsibility of the Product Provider.
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Programmatic Authentication. The Jakarta EE product must provide for specification of the principal and authentication data for a resource by the application component at runtime using appropriate APIs. The application may obtain the principal and authentication data through a variety of mechanisms, including receiving them as parameters, obtaining them from the component’s environment, and so forth.
In addition, the following techniques are recommended but not required by this specification:
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Principal Mapping. A resource can have a principal and attributes that are determined by a mapping from the identity and security attributes of the requesting principal. In this case, a resource principal is not based on inheritance of the identity or security attributes from a requesting principal, but gets its identity and security attributes based on the mapping.
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Caller Impersonation. A resource principal acts on behalf of a requesting principal. Acting on behalf of a caller principal requires delegation of the caller’s identity and credentials to the underlying resource manager. In some scenarios, a requesting principal can be a delegate of an initiating principal and the resource principal is transitively impersonating an initiating principal.
The support for principal delegation is typically specific to a security mechanism. For example, Kerberos supports a mechanism for the delegation of authentication. (Refer to the Kerberos v5 specification for more details.)
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Credentials Mapping. This technique may be used when an application server and an EIS support different authentication domains. For example:
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The initiating principal may have been authenticated and have public key certificate-based credentials.
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The security environment for the resource manager may be configured with the Kerberos authentication service.
The application server is configured to map the public key certificate-based credentials associated with the initiating principal to the Kerberos credentials.
Additional information on resource authentication requirements can be found in the Connector specification.
3.5. Authorization Requirements
To support the authorization models described in this chapter, the following requirements are imposed on Jakarta EE products.
3.5.1. Code Authorization
A Jakarta EE product may restrict the use of certain Java SE classes and methods to secure and ensure proper operation of the system. The minimum set of permissions that a Jakarta EE product is required to grant to a Jakarta EE application is defined in Java Platform, Standard Edition (Java SE) Requirements. All Jakarta EE products must be capable of deploying application components with exactly these permissions.
A Jakarta EE Product Provider may choose to enable selective access to resources using the Java protection model. The mechanism used is Jakarta EE product dependent.
The permissions.xml descriptor (see Declaring Permissions Required by Application Components) makes it possible to express permissions that a component needs for access.
3.5.2. Caller Authorization
A Jakarta EE product must enforce the access control rules specified at deployment time (see Deployment Requirements) and more fully described in the Jakarta Enterprise Beans and Servlet specifications.
3.5.3. Propagated Caller Identities.
In a Jakarta EE product that contains an Jakarta Enterprise Beans container, it must be possible to configure the Jakarta EE product so that a propagated caller identity is used in all authorization decisions. With this configuration, for all calls to all enterprise beans from a single application within a single Jakarta EE product, the principal name returned by the EJBContext method getCallerPrincipal or the SecurityContext method getCallerPrincipal must be the same as that returned by the first enterprise bean in the call chain. If the first enterprise bean in the call chain is called by a servlet or JSP page, the principal name must be the same as that returned by the HttpServletRequest method getUserPrincipal or the SecurityContext method getCallerPrincipal in the calling servlet or JSP page. (However, if the HttpServletRequest or SecurityContext method getCallerPrincipal returns null , the principal used in calls to enterprise beans is not specified by this specification, although it must still be possible to configure enterprise beans to be callable by such components.)
Note that this does not require delegation of credentials, only identification of the caller. A single principal must be the principal used in authorization decisions for access to all enterprise beans in the call chain. The requirements in this section apply only when a Jakarta EE product has been configured to propagate caller identity.
3.5.4. Run As Identities
Jakarta EE products must also support the Run As capability that allows the Application Component Provider and the Deployer to specify an identity under which an enterprise bean or web component must run. In this case it is the Run As identity that is propagated to subsequent Jakarta Enterprise Beans components, rather than the original caller identity.
Note that this specification doesn’t specify any relationship between the Run As identity and any underlying operating system identity that may be used to access system resources such as files. However, the Jakarta Authorization specification does specify the relationship between the Run As identity and the access control context used by the Java SE security manager.
3.6. Deployment Requirements
All Jakarta EE products must implement the access control semantics described in all included component specifications, such as the Jakarta Enterprise Beans, Jakarta Server Pages, and Jakarta Servlet specifications; provide a means of mapping the security roles specified in metadata annotations or the deployment descriptor to the actual roles exposed by a Jakarta EE product; and support the default mapping from user groups to roles defined by the Jakarta Security specification.
While most Jakarta EE products will allow the Deployer to customize the role mappings and change the assignment of roles to methods, all Jakarta EE products must support the ability to deploy applications and components using exactly the mappings and assignments specified in their metadata annotations or deployment descriptors.
As described in the Jakarta Enterprise Beans specification and the Servlet specification, a Jakarta EE product must provide a deployment tool or tools capable of assigning the security roles in metadata annotations or deployment descriptors to the entities that are used to determine role membership at authorization time.
Application developers will need to specify (in the application’s metadata annotations or deployment descriptors) the security requirements of an application in which some components may be accessed by unauthenticated users as well as authenticated users (as described above in Unauthenticated Users). Applications express their security requirements in terms of security roles, which the Deployer maps to users (principals) in the operational environment at deployment time. An application might define a role representing all authenticated and unauthenticated users and configure some enterprise bean methods to be accessible by this role.
To support such usage, this specification requires that it be possible to map an application defined security role to the universal set of application principals independent of authentication. __
3.7. Future Directions
3.7.1. Auditing
This specification does not specify requirements for the auditing of security relevant events, nor APIs for application components to generate audit records. A future version of this specification may include such a specification for products that choose to provide auditing.
3.7.2. Instance-based Access Control
Some applications need to control access to their data based on the content of the data, rather than simply the type of the data. We refer to this as “instance-based” rather than “class-based” access control. We hope to address this in a future release.
3.7.3. User Registration
Web-based internet applications often need to manage a set of customers dynamically, allowing users to register themselves as new customers. This scenario was widely discussed in the Servlet expert group (JSR-53) but we were unable to achieve consensus on the appropriate solution. We had to abandon this work for J2EE 1.3, and were not able to address it for J2EE 1.4, but hope to pursue it further in a future release.
4. Transaction Management
This chapter describes the required Jakarta Enterprise Edition (Jakarta EE) transaction management and runtime environment.
Product Providers must transparently support transactions that involve multiple components and transactional resources within a single Jakarta EE product, as described in this chapter. This requirement must be met regardless of whether the Jakarta EE product is implemented as a single process, multiple processes on the same network node, or multiple processes on multiple network nodes.
If the following components are included in a Jakarta EE product, they are considered transactional resources and must behave as specified here:
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JDBC connections
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Jakarta Messaging sessions
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Resource adapter connections for resource adapters specifying the XATransaction transaction level
4.1. Overview
A Jakarta EE Product that includes both a servlet container and an enterprise bean container must support a transactional application comprised of combinations of web application components accessing multiple enterprise beans within a single transaction. If the Jakarta EE product also includes support for the Connectors specification, each component may also acquire one or more connections to access one or more transactional resource managers.
For example, in Servlets/Server Pages Accessing Enterprise Beans , the call tree starts from a servlet or server pages accessing multiple enterprise beans, which in turn may access other enterprise beans. The components access resource managers via connections.
The Application Component Provider specifies, using a combination of programmatic and declarative transaction demarcation APIs, how the platform must manage transactions on behalf of the application.
For example, the application may require that all the components in Servlets/Server Pages Accessing Enterprise Beans access resources as part of a single transaction. The Platform Provider must provide the transaction capabilities to support such a scenario.
This specification does not define how the components and the resources are partitioned or distributed within a single Jakarta EE product. In order to achieve the transactional semantics required by the application, the Jakarta EE Product Provider is free to execute the application components sharing a transaction in the same Java virtual machine, or distribute them across multiple virtual machines, in accordance with the requirements of the component specifications.
The rest of this chapter describes the transactional requirements for a Jakarta EE product in more detail.
4.2. Requirements
This section defines the transaction support requirements of Jakarta EE Products that must be supported by Product Providers.
4.2.1. Web Components
Web components may demarcate transactions using the javax.transaction.UserTransaction interface or transactional interceptors, which are defined in the Jakarta Transactions specification. They may access multiple resource managers and invoke multiple enterprise beans within a single transaction. The specified transaction context is automatically propagated to the enterprise beans and transactional resource managers. The result of the propagation may be subject to the enterprise bean transaction attributes (for example, a bean may be required to use Container Managed Transactions).
Web application event listeners and upgrade handlers must not demarcate transactions using the javax.transaction.UserTransaction interface or transactional interceptors. Servlet filters may use transactional resources within their doFilter methods but should not use any transactional resources in the methods of any objects used to wrap the request or response objects.
4.2.1.1. Transaction Requirements
The Jakarta EE platform must meet the following requirements:
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The Jakarta EE platform must provide an object implementing the javax.transaction.UserTransaction interface to all web components. The platform must publish the UserTransaction object in the Java™ Naming and Directory Interface (JNDI) name space available to web components under the name java:comp/UserTransaction.
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The Jakarta EE platform must provide classes that implement the transactional interceptors, as defined by the Jakarta Transactions specification.
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If a web component invokes an enterprise bean from a thread associated with a transaction defined by the Jakarta Transactions specification, the Jakarta EE platform must propagate the transaction context with the enterprise bean invocation. Whether the target enterprise bean will be invoked in this transaction context or not is determined by the rules defined in the Jakarta Enterprise Beans specification.
Note that this transaction propagation requirement applies only to invocations of enterprise beans in the same Jakarta EE product instance [2] as the invoking component. Invocations of enterprise beans in another Jakarta EE product instance (for example, using the Jakarta Enterprise Beans interoperability protocol) need not propagate the transaction context. See the Jakarta Enterprise Beans specification for details.
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If a web component accesses a transactional resource manager from a thread associated with a transaction defined by the Jakarta Transactions specification, the Jakarta EE platform must ensure that the resource access is included as part of the transaction defined by the Jakarta Transactions specification.
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If a web component creates a thread, the Jakarta EE platform must ensure that the newly created thread is not associated with any transaction defined by the Jakarta Transactions specification.
4.2.1.2. Transaction Non-Requirements
The Product Provider is not required to support the importing of a transaction context from a client to a web component.
The Product Provider is not required to support transaction context propagation via an HTTP request across web components. The HTTP protocol does not support such transaction context propagation. When a web component associated with a transaction makes an HTTP request to another web component, the transaction context is not propagated to the target servlet or page.
However, when a web component is invoked through the RequestDispatcher interface, any active transaction context must be propagated to the called servlet or server pages.
4.2.2. Transactions in Web Component Life Cycles
Transactions may not span web requests from a client on the network. If a web component starts a transaction in the service or doFilter method (or transactional interceptor of service or doFilter method), it must be completed before the service or doFilter method returns to the network client.[3] Returning from the service or doFilter method to the network client with an active transaction context is an error. The web container is required to detect this error and abort the transaction.
As specified above in Transaction Non-Requirements, requests made within a web container using the RequestDispatcher must propagate any transaction context to the called class. Unless the called class commits or aborts the transaction, the transaction must remain active when the called class returns.
If a servlet that is called via the RequestDispatcher starts a transaction, the behavior of the container with regard to that transaction is unspecified when the servlet returns from its service method. The web container may throw an exception to the caller, abort the transaction and return to the caller without error, or propagate the transaction context back to the caller. Portable servlets will complete any transaction they start before returning from the service method.
4.2.3. Transactions and Threads
There are many subtle and complex interactions between the use of transactional resources and threads. To ensure correct operation, web components should obey the following guidelines, and the web container must support at least these usages.
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Transactions defined by the Jakarta Transactions specification should be started and completed in the thread in which the service method is called. Additional threads that are created for any purpose should not attempt to start transactions defined by the Jakarta Transactions specification.
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Transactional resources may be acquired and released by a thread other than the service method thread, but should not be shared between threads.
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Transactional resource objects (for example, JDBC Connection objects) should not be stored in static fields. Such objects can only be associated with one transaction at a time. Storing them in static fields would make it easy to erroneously share them between threads in different transactions.
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Web components implementing SingleThreadModel may store top-level transactional resource objects in class instance fields. A top-level object is one acquired directly from a container managed connection factory object (for example, a JDBC Connection acquired from a JDBC ConnectionFactory ), as opposed to other objects acquired from these top-level objects (for example, a JDBC Statement acquired from a JDBC Connection ). The web container ensures that requests to a SingleThreadModel servlet are serialized and thus only one thread and one transaction will be able to use the object at a time, and that the top-level object will be enlisted in any new transaction started by the component.
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In web components not implementing SingleThreadModel , transactional resource objects, as well as Java Persistence EntityManager objects, should not be stored in class instance fields, and should be acquired and released within the same invocation of the service method.
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Web components that are called by other web components (using the forward or include methods) should not store transactional resource objects in class instance fields.
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Enterprise beans may be invoked from any thread used by a web component. Transaction context propagation requirements are described above and in the Jakarta Enterprise Beans specification.
4.2.4. Jakarta Enterprise Beans Components
The Jakarta EE Product Provider must provide support for transactions as defined in the Jakarta Enterprise Beans specification.
4.2.5. Application Clients
The Jakarta EE Product Provider is not required to provide transaction management support for application clients.
4.2.6. Applet Clients
The Jakarta EE Product Provider is not required to provide transaction management support for applets.
4.2.7. Transactional JDBC™ Technology Support
A Jakarta EE product must support a JDBC technology database as a transactional resource manager. The platform must enable transactional JDBC API access from web components and enterprise beans.
It must be possible to access the JDBC technology database from multiple application components within a single transaction. For example, a servlet may wish to start a transaction, access a database, invoke an enterprise bean that accesses the same database as part of the same transaction, and, finally, commit the transaction.
A Jakarta EE product must provide a transaction manager that is capable of coordinating two-phase commit operations across multiple XA-capable JDBC databases. If a JDBC driver supports the Jakarta Transactions API’s XA interfaces (in the javax.transaction.xa package), then the Jakarta EE product must be capable of using the XA interfaces provided by the JDBC driver to accomplish two-phase commit operations. The Jakarta EE product may discover the XA capabilities of JDBC drivers through product-specific means, although normally such JDBC drivers would be delivered as resource adapters using the Connector API.
4.2.8. Transactional Jakarta Messaging Support
A Jakarta EE product must support a Jakarta Messaging provider as a transactional resource manager. The platform must enable transactional Jakarta Messaging access from servlets, server pages, and enterprise beans.
It must be possible to access the Jakarta Messaging provider from multiple application components within a single transaction. For example, a servlet may wish to start a transaction, send a Jakarta Messaging message, invoke an enterprise bean that also sends a Jakarta Messaging message as part of the same transaction, and, finally, commit the transaction.
4.2.9. Transactional Resource Adapter (Connector) Support
A Jakarta EE product must support resource adapters that use XATransaction mode as transactional resource managers. The platform must enable transactional access to the resource adapter from servlets, server pages, and enterprise beans.
It must be possible to access the resource adapter from multiple application components within a single transaction. For example, a servlet may wish to start a transaction, access the resource adapter, invoke an enterprise bean that also accesses the resource adapter as part of the same transaction, and, finally, commit the transaction.
4.3. Transaction Interoperability
4.3.1. Multiple Jakarta EE Platform Interoperability
This specification does not require the Product Provider to implement any particular protocol for transaction interoperability across multiple Jakarta EE products. Jakarta EE compatibility requires neither interoperability among identical Jakarta EE products from the same Product Provider, nor among heterogeneous Jakarta EE products from multiple Product Providers.
We recommend that Jakarta EE Product Providers use the IIOP transaction propagation protocol defined by OMG and described in the OTS specification, transaction interoperability when using the Jakarta Enterprise Beans interoperability protocol based on RMI-IIOP.
4.3.2. Support for Transactional Resource Managers
This specification requires all Jakarta EE products to support the javax.transaction.xa.XAResource interface, as specified in the Connector specification. This specification also requires all Jakarta EE products to support the javax.transaction.xa.XAResource interface for performing two-phase commit operations on JDBC drivers that support the JTA XA APIs. This specification does not require that JDBC drivers or Jakarta Messaging providers use the javax.transaction.xa.XAResource interface, although they may use this interface and in all cases they must meet the transactional resource manager requirements described in this chapter. In particular, it must be possible to combine operations on one or more JDBC databases, one or more Jakarta Messaging sessions, one or more enterprise beans, and multiple resource adapters supporting the XATransaction mode in a single transaction defined by the Jakarta Transactions specification.
4.4. Local Transaction Optimization
4.4.1. Requirements
If a transaction uses a single resource manager, performance may be improved by using a resource manager specific local optimization. A local transaction is typically more efficient than a global transaction and provides better performance. Local optimization is not available for transactions that are imported from a different container.
Containers may choose to provide local transaction optimization, but are not required to do so. Local transaction optimization must be transparent to a Jakarta EE application.
The following section describes a possible mechanism for local transaction optimization by containers.
4.4.2. A Possible Design
This section illustrates how the previously described requirements might be implemented.
When the first connection to a resource manager is established as part of the transaction, a resource manager specific local transaction is started on the connection. Any subsequent connection acquired as part of the transaction that can share the local transaction on the first connection is allowed to share the local transaction.
A global transaction is started lazily under the following conditions:
-
When a subsequent connection cannot share the resource manager local transaction on the first connection, or if it uses a different resource manager.
-
When a transaction is exported to a different container.
After the lazy start of a global transaction, any subsequent connection acquired may either share the local transaction on the first connection, or be part of the global transaction, depending on the resource manager it accesses.
When a transaction completion (commit or rollback) is attempted, there are two possibilities:
-
If only a single resource manager had been accessed as part of the transaction, the transaction is completed using the resource manager specific local transaction mechanism.
-
If a global transaction had been started, the transaction is completed treating the resource manager local transaction as a last resource in the global 2-phase commit protocol, that is using the last resource 2-phase commit optimization.
4.5. Connection Sharing
When multiple connections acquired by a Jakarta EE application use the same resource manager, containers may choose to provide connection sharing within the same transaction scope. Sharing connections typically results in efficient usage of resources and better performance. Containers are required to provide connection sharing in certain situations; see the Connector specification for details.
Connections to resource managers acquired by Jakarta EE applications are considered potentially shared or shareable. A Jakarta EE application component that intends to use a connection in an unshareable way must provide deployment information to that effect, to prevent the connection from being shared by the container. Examples of when this may be needed include situations with changed security attributes, isolation levels, character settings, and localization configuration. Containers must not attempt to share connections that are marked unshareable. If a connection is not marked unshareable, it must be transparent to the application whether the connection is actually shared or not.
Jakarta EE application components may use the optional shareable element of the Resource annotation or the optional deployment descriptor element res-sharing-scope to indicate whether a connection to a resource manager is shareable or unshareable. Containers must assume connections to be shareable if no deployment hint is provided. Jakarta EE Application Client XML Schema, the Jakarta Enterprise Beans specification, and the Servlet specification provide descriptions of the deployment descriptor element.
Jakarta EE application components may cache connection objects and reuse them across multiple transactions. Containers that provide connection sharing must transparently switch such cached connection objects (at dispatch time) to point to an appropriate shared connection with the correct transaction scope. Refer to the Connector specification for a detailed description of connection sharing.
4.6. JDBC and Jakarta Messaging Deployment Issues
The JDBC transaction requirements in Transactional JDBC™ Technology Support and the Jakarta Messaging transaction requirements in Transactional Jakarta Messaging Support may impose some restrictions on a Deployer’s configuration of an application’s JDBC and Jakarta Messaging resources. Jakarta EE Product Providers may impose the restrictions described in this section to meet these requirements.
If the deployer configures a non-XA-capable JDBC resource manager in a transaction, then a Jakarta EE Product Provider may restrict all JDBC access within that transaction to that non-XA-capable JDBC resource manager. Otherwise, a Jakarta EE Product Provider must support use of multiple XA-capable JDBC resource managers within a transaction. In addition, a Jakarta EE Product Provider may restrict the security configuration of all JDBC connections within a transaction to a single user identity. A Jakarta EE Product Provider is not required to support transactions where more than one JDBC identity is used. Specifically, this means that transactions that require the use of more than one JDBC security identity (which can be done explicitly via component provided user name and password) may not be portable.
A Jakarta EE Product Provider may make the same restrictions as above, resulting in a transaction being restricted to a single Jakarta Messaging resource manager and user identity.
In addition, when both a JDBC resource manager and a Jakarta Messaging resource manager are used in the same transaction, a Jakarta EE Product Provider may restrict both to a pairing that allows their combination to deliver the full transactional semantics required by the application, and may restrict the security identity of both to a single identity. To fully support such usage, portable applications that wish to include JDBC and Jakarta Messaging access in a single global transaction must not mark the corresponding transactional resources as “unshareable”.
Although these restrictions are allowed, it is recommended that Jakarta EE Product Providers support JDBC and Jakarta Messaging resource managers that provide full two-phase commit functionality and, as a result, do not impose these restrictions.
4.7. Two-Phase Commit Support
A Jakarta EE product must support the use of multiple XA-capable resource adapters in a single transaction. To support such a scenario, full two-phase commit support is required. A Jakarta Messaging provider may be provided as an XA-capable resource adapter. In such a case, it must be possible to include Jakarta Messaging operations in the same global transaction as other resource adapters. While JDBC drivers are not required to be XA-capable, a JDBC driver may be delivered as an XA-capable resource adapter. In such a case, it must be possible to include JDBC operations in the same global transaction as other XA-capable resource adapters. See also Transactional JDBC™ Technology Support.
4.8. System Administration Tools
Although there are no compatibility requirements for system administration capabilities, the Jakarta EE Product Provider will typically include tools that allow the System Administrator to perform the following tasks:
-
Integrate transactional resource managers with the platform.
-
Configure the transaction management parts of the platform.
-
Monitor transactions at runtime.
-
Receive notifications of abnormal transaction processing conditions (such as abnormally high number of transaction rollbacks).
5. Resources, Naming, and Injection
This chapter describes how applications declare dependencies on external resources and configuration parameters, and how those items are represented in the Jakarta EE naming system and can be injected into application components. These requirements are based on annotations defined in the Java Metadata specification and features defined in the Java Naming and Directory Interface™ (JNDI) specification. The Resource annotation described here is defined in more detail in the Jakarta Annotations specification. The EJB annotation described here is defined in more detail in the Enterprise JavaBeans specification. The PersistenceUnit and PersistenceContext annotations described here are defined in more detail in the Java Persistence specification. The Inject annotation described here is defined in the Dependency Injection for Java specification, and its usage in Jakarta EE applications is defined in the CDI specification.
5.1. Overview
The requirements defined in this chapter address the following two issues:
-
The Application Assembler and Deployer should be able to customize the behavior of an application’s business logic without accessing the application’s source code. Typically this will involve specification of parameter values, connection to external resources, and so on. Deployment descriptors provide this capability
-
Applications must be able to access resources and external information in their operational environment without knowledge of how the external information is named and organized in that environment. The JNDI naming context and Java language annotations provide this capability.
5.1.1. Chapter Organization
The following sections contain the Jakarta EE platform solutions to the above issues:
-
JNDI Naming Context,” defines general rules for the use of the JNDI naming context and its interaction with Java language annotations that reference entries in the naming context.
-
Responsibilities by Jakarta EE Role,” defines the general responsibilities for each of the Jakarta EE roles such as Application Component Provider, Application Assembler, Deployer, and Jakarta EE Product Provider.
-
Simple Environment Entries,” defines the basic interfaces that specify and access the application component’s naming environment. The section illustrates the use of the application component’s naming environment for generic customization of the application component’s business logic.
-
Jakarta Enterprise Beans References,” defines the interfaces for obtaining the business interface, no-interface view, or home interface of an enterprise bean using a Jakarta Enterprise Bean reference. A Jakarta Enterprise Bean reference is a special entry in the application component’s environment.
-
Web Service References,” refers to the specification for web service references.
-
Resource Manager Connection Factory References,” defines the interfaces for obtaining a resource manager connection factory using a resource manager connection factory reference. A resource manager connection factory reference is a special entry in the application component’s environment.
-
Resource Environment References,” defines the interfaces for obtaining an administered object that is associated with a resource using a resource environment reference. A resource environment reference is a special entry in the application component’s environment.
-
Message Destination References,” defines the interfaces for declaring and using message destination references.
-
UserTransaction References,” describes the use by eligible application components of references to a UserTransaction object in the component’s environment to start, commit, and abort transactions.
-
TransactionSynchronizationRegistry References,” describes the use by eligible application components of references to a TransactionSynchronizationRegistry object in the component’s environment.
-
ORB References,” describes the use by eligible application components of references to a CORBA ORB object in the component’s environment.
-
Persistence Unit References,” describes the use by eligible application components of references to an EntityManagerFactory object in the component’s environment.
-
Persistence Context References,” describes the use by eligible application components of references to an EntityManager object in the component’s environment.
-
Application Name and Module Name References,” describes the use by eligible application components of references to the names of the current application and module.
-
Application Client Container Property,” describes the use by eligible application components of references to the application client container property.
-
Validator and Validator Factory References,” describes the use by eligible application components of references to the Validator and ValidatorFactory objects in the component’s environment.
-
Resource Definition and Configuration,” describes the use by eligible application components of metadata that may be used to define resources in the component’s environment.
-
DataSource Resource Definition,” describes the use by eligible application components of references to DataSource resources in the component’s environment.
-
Jakarta Messaging Connection Factory Resource Definition,” describes the use by eligible application components of references to Jakarta Messaging ConnectionFactory resources in the component’s environment.
-
Jakarta Messaging Destination Definition,” describes the use by eligible application components of references to Jakarta Messaging Destination resources in the component’s environment.
-
Mail Session Definition,” describes the use by eligible application components of references to Mail Session resources in the component’s environment.
-
Connector Connection Factory Definition,” describes the use by eligible application components of references to Connector connection factory resources in the component’s environment.
-
Connector Administered Object Definition,” describes the use by eligible application components of references to Connector administered object resources in the component’s environment.
-
Default Data Source,” describes the use by eligible application components of references to the default DataSource in the component’s environment.
-
Default Jakarta Messaging Connection Factory,” describes the use by eligible application components of references to the default Jakarta Messaging ConnectionFactory in the component’s environment.
-
Default Jakarta Concurrency Objects,” describes the use by eligible application components of references to the default Jakarta Concurrency objects in the component’s environment.
-
Managed Bean References,” describes the use by eligible application components of references to Managed Beans.
-
Bean Manager References,” describes the use by eligible application components of references to a BeanManager object in the component’s environment.
-
Support for Dependency Injection,” describes support for the use of the Dependency Injection APIs.
5.1.2. Required Access to the JNDI Naming Environment
Jakarta EE application clients, enterprise beans, and web components are required to have access to a JNDI naming environment.[4] The containers for these application component types are required to provide the naming environment support described here.
Annotations and deployment descriptors are the main vehicles for conveying access information to the Application Assembler and Deployer about application components’ requirements for customization of business logic and access to external information. The annotations described here are available for use by all application component types. The deployment descriptor entries described here are present in identical form in the deployment descriptor schemas for each of these application component types. See the corresponding specification of each application component type for the details.
5.2. JNDI Naming Context
The application component’s naming environment is a mechanism that allows customization of the application component’s business logic during deployment or assembly. Use of the application component’s environment allows the application component to be customized without the need to access or change the application component’s source code.
5.2.1. The Application Component’s Environment
The container implements the application component’s environment, and provides it to the application component instance as a JNDI naming context. The application component’s environment is used as follows:
-
The application component’s business methods make use of entries from the environment. The business methods may access the environment using the JNDI interfaces or lookup methods on component-specific context objects. Also, entries from the environment may be injected into the application component’s fields or methods. The Application Component Provider declares in the deployment descriptor, or via annotations, all the environment entries that the application component expects to be provided in its environment at runtime. For each environment entry, the Application Component Provider can also specify in the deployment descriptor, or via annotations, the JNDI name of another environment entry whose value should be used to initialize the environment entry being defined (“lookup” functionality).
-
The container provides an implementation of the JNDI naming context that stores the application component environment. The container also provides the tools that allow the Deployer to create and manage the environment of each application component.
-
The Deployer uses the tools provided by the container to initialize the environment entries that are declared in the application component’s deployment descriptor or via annotations. The Deployer can set and modify the values of the environment entries. As part of this process, the Deployer is allowed to override any “lookup” information associated with the application component.
-
The container injects entries from the environment into application component fields or methods as specified by the application component’s deployment descriptor or by annotations on the application component class.
-
The container also makes the environment naming context available to the application component instances at runtime. The application component’s instances may use the JNDI interfaces or component context lookup methods to obtain the values of the environment entries. __
5.2.2. Application Component Environment Namespaces
The application component’s naming environment is composed of four logical namespaces, representing naming environments with different scopes. The four namespaces are: __
-
java:comp – Names in this namespace are per-component (for example, per enterprise bean). Except for components in a web module, each component gets its own java:comp namespace, not shared with any other component. Components in a web module do not have their own private component namespace. __ See note below.
-
java:module – Names in this namespace are shared by all components in a module (for example, all enterprise beans in a single enterprise bean module, or all components in a web module). __
-
java:app – Names in this namespace are shared by all components in all modules in a single application, where “single application” means a single deployment unit, such as a single ear file, a single module deployed standalone, etc. For example, a war file and a Jakarta Enterprise Beans jar file in the same ear file would both have access to resources in the java:app namespace. __
-
java:global – Names in this namespace are shared by all applications deployed in an application server instance. Note that an application server instance may represent a single server, a cluster of servers, an administrative domain containing many servers, or even more. The scope of an application server instance is product-dependent, but it must be possible to deploy multiple applications to a single application server instance.
Note that in environments in which an application is deployed multiple times—such as, for example, in cloud environments, where multiple instances of the same application might be deployed on behalf of multiple tenants—the namespace for each application instance would be disjoint from the namespace of any other instance of that same application.
For historical reasons, the java:comp namespace is shared by all components in a web module. To preserve compatibility, this specification doesn’t change that. In a web module, java:comp refers to the same namespace as java:module . It is recommended that resources in a web module that are intended to be shared by more than one component be declared in the java:module/env namespace.
Note that an application client is a module with only a single component.
Note also that resource adapter (connector) modules may not define resources in any of the component namespaces, but may look up resources defined by other components. All the java: namespaces accessible in a resource adapter are the namespaces of the component that called the resource adapter (when called in the context of a component).
If multiple application components declare an environment entry in one of the shared namespaces, all attributes of that entry must be identical in each declaration. For example, if multiple components declare a resource reference with the same java:app name, the authentication and shareable attributes must be identical.
If all attributes of each declaration of a shared environment entry are not identical, this must be reported as a deployment error to the Deployer. The deployment tool may allow the Deployer to correct the error and continue deployment.
The default JNDI namespace for resource references and resource definitions must always be java:comp/env . Note that this applies to both the case where no name has been supplied so the rules for choosing a default name are used, and the case where a name has been supplied explicitly but the name does not specify a java: namespace. Since the java:comp namespace is not available in some contexts, use of that namespace in such a context should result in a deployment error. Likewise, the java:module namespace is not valid in some contexts; use of that namespace in such contexts should result in a deployment error. Environment entries may be declared in any one of the defined namespaces by explicitly including the namespace prefix before the name.
It is recommended but not required that environment entries be created in the env subcontext of the corresponding naming context. For example, entries shared within a module should be declared in the java:module/env context. Note that names that are not under the env subcontext may conflict with the current or future versions of this specification, with server-defined names, such as the names of applications or modules, or with server-defined resources. Names in the env subcontexts of any of the namespaces must only be created by an explicit declaration in an application or by an explicit action by an administrator; the application server must not predefine any names in the env subcontext of any of the namespaces, or in any subcontext of any such env context.
An environment entry declared in the application.xml descriptor must specify a JNDI name in the java:app or java:global namespace, for example: java:app/env/myString or java:global/someValue . The specification of a java:comp or java:module name for an environment entry declared in the application.xml descriptor must be reported as a deployment error to the Deployer.
A Jakarta EE product may impose security restrictions on access of resources in the shared namespaces. However, it must be possible to deploy applications that define resources in the shared namespaces that are usable by different entities at the given scope. For example, it must be possible to deploy an application that defines a resource, using various forms of metadata declaration, in the java:global namespace that is usable by a separate application.
5.2.3. Accessibility of Environment Entry Types
All objects defined in environment entries of any kind (either in deployment descriptors or through annotations) must be specified to be of a Java type that is accessible to the component. Accessibility of Java classes is specified in section Class Loading Requirements.” If the object is of type java.lang.Class , the Class object must refer to a class that is accessible to the component. Note that in cases where the container may return an implementation subtype of the requested type, the implementation subtype might not be accessible to the component.
5.2.4. Sharing of Environment Entries
Each application component defines its own set of dependencies that must appear as entries in the application component’s environment. All instances of an application component within the same application instance within the same container share the same environment entries. Application component instances are not allowed to modify the environment at runtime.
In general, lookups of objects in the JNDI java: namespace are required to return a new instance of the requested object every time. Exceptions are allowed for the following:
-
The container knows the object is immutable (for example, objects of type java.lang.String ), or knows that the application can’t change the state of the object.
-
The object is defined to be a singleton, such that only one instance of the object may exist in the JVM.
-
The name used for the lookup is defined to return an instance of the object that might be shared. The names java:comp/ORB , java:comp/ValidatorFactory , and java:comp/BeanManager are such names.
In these cases, a shared instance of the object may be returned. In all other cases, a new instance of the requested object must be returned on each lookup. Note that, in the case of resource adapter connection objects, it is the resource adapter’s ManagedConnectionFactory implementation that is responsible for satisfying this requirement.
Each injection of an object corresponds to a JNDI lookup. Whether a new instance of the requested object is injected, or whether a shared instance is injected, is determined by the rules described above. __
5.2.5. Annotations and Injection
As described in the following sections, a field or method of certain container-managed component classes may be annotated to request that an entry from the application component’s environment be injected into the class. The specifications for the different containers indicate which classes are considered container-managed classes; not all classes of a given type are necessarily managed by the container.
Any of the types of resources described in this chapter may be injected. Injection may also be requested using entries in the deployment descriptor corresponding to each of these resource types. The field or method may have any access qualifier ( public , private , etc.). For all classes except application client main classes, the fields or methods must not be static . Because application clients use the same lifecycle as Java SE applications, no instance of the application client main class is created by the application client container. Instead, the static main method is invoked. To support injection for the application client main class, the fields or methods annotated for injection must be static .
A field of a class may be the target of injection. The field must not be final . By default, the name of the field is combined with the fully qualified name of the class and used directly as the name in the application component’s naming context. For example, a field named myDatabase in the class MyApp in the package com.example would correspond to the JNDI name java:comp/env/com.example.MyApp/myDatabase . The annotation also allows the JNDI name to be specified explicitly. When a deployment descriptor entry is used to specify injection, the JNDI name and the field name are both specified explicitly. Note that, by default, the JNDI name is relative to the java:comp/env naming context.
Environment entries may also be injected into a class through methods that follow the naming conventions for JavaBeans properties. The annotation is applied to the set method for the property, which is the method that is called to inject the environment entry into the class. The JavaBeans property name (not the method name) is used as the default JNDI name. For example, a method named setMyDatabase in the same MyApp class would correspond to the same JNDI name java:comp/env/com.example.MyApp/myDatabase as the field myDatabase .
Each resource may only be injected into a single field or method of a given name in a given class. Requesting injection of the java:comp/env/com.example.MyApp/myDatabase resource into both the setMyDatabase method and the myDatabase field is an error. Note, however, that either the field or the method could request injection of a resource of a different (non-default) name. By explicitly specifying the JNDI name of a resource, a single resource may be injected into multiple fields or methods of multiple classes.
The specifications for the various application component types describe which classes may be annotated for injection, as summarized in Component classes supporting injection.
The component classes listed in Component classes supporting injection with support level “Standard” all support Jakarta EE resource injection, as well as PostConstruct and PreDestroy callbacks. In addition, if CDI is enabled—which it is by default—these classes also support CDI injection, as described in Support for Dependency Injection”, and the use of interceptors.[5] The component classes listed with support level “Limited” only support Jakarta EE field injection and the PostConstruct callback. Note that these are application client main classes, where field injection is into static fields.
The specifications for the various application component types also describe when injection occurs in the lifecycle of the component. Typically injection will occur after an instance of the class is constructed, but before any business methods are called. If the container fails to find a resource needed for injection, initialization of the class must fail, and the class must not be put into service.
Spec | Classes supporting injection | Support level |
---|---|---|
Servlet |
servlets servlet filters event listeners HTTP upgrade handlers |
Standard Standard Standard Standard |
Jakarta Server Pages |
tag handlers tag library event listeners |
Standard Standard |
Jakarta Server Faces |
managed classes [6] |
Standard |
JAX-WS |
service endpoints handlers |
Standard Standard |
Jakarta RESTful Web Services |
Jakarta RESTful Web Services components [7] |
Standard |
WebSocket |
endpoints |
Standard |
Jakarta Enterprise Beans |
beans |
Standard |
Interceptor |
interceptors [8] |
Standard |
Java Persistence |
entity listeners |
Standard |
Managed Beans |
managed beans |
Standard |
CDI [9] |
CDI-style managed beans [10] decorators [11] |
Standard Standard |
Jakarta EE platform |
main class (static) login callback handler |
Limited Standard |
Annotations may also be applied to the class itself. These annotations declare an entry in the application component’s environment but do not cause the resource to be injected. Instead, the application component is expected to use JNDI or a component context lookup method to lookup the entry. When the annotation is applied to the class, the JNDI name and the environment entry type must be specified explicitly. __
Resource annotations may appear on any of the classes listed above, or on any superclass of any class listed above. A resource annotation on any class in the inheritance hierarchy defines a resource needed by the application component. However, injection of resources follows the Java language overriding rules for visibility of fields and methods. A method definition that overrides a method on a superclass defines the resource, if any, to be injected into that method. An overriding method may request injection even though the superclass method does not request injection, it may request injection of a different resource than is requested by the superclass, or it may request no injection even though the superclass method requests injection.
In addition, fields or methods that are not visible in or are hidden (as opposed to overridden) by a subclass may still request injection. This allows, for example, a private field to be the target of injection and that field to be used in the implementation of the superclass, even though the subclass has no visibility into that field and doesn’t know that the implementation of the superclass is using an injected resource. Note a declaration of a field in a subclass with the same name as a field in a superclass always causes the field in the superclass to be hidden.
In some cases a class may need to perform initialization of its own after all resources have been injected. To support this case, one method of the class may be annotated with the PostConstruct annotation (or, equivalently, specified using the post-construct entry of a deployment descriptor). This method will be called after all injections have occured and before the class is put into service. This method will be called even if the class doesn’t request any resources to be injected. Similarly, for classes whose lifecycle is managed by the container, the PreDestroy annotation (or, equivalently, the pre-destroy entry of a deployment descriptor) may be applied to one method that will be called when the class is taken out of service and will no longer be used by the container. Each class in a class hierarchy may have PostConstruct and PreDestroy methods. The order in which the methods are called matches the order of the class hierarchy with methods on a superclass being called before methods on a subclass.
The PostConstruct and PreDestroy annotations are specified by the Jakarta Annotations specification. All classes that support injection also support the PostConstruct annotation. All classes for which the container manages the full lifecycle of the object also support the PreDestroy annotation.
Starting with Java EE 7, CDI support is enabled by default. CDI bean-defining annotations and the beans.xml descriptor are used to determine which classes are CDI beans and eligible for injection into other objects. Similarly, the annotation metadata and the beans.xml descriptor are used by CDI to determine which interceptors are eligible to be applied. See the CDI specification and the Interceptors specification for the rules that determine which classes are CDI beans and the treatment of interceptors.
5.2.6. Annotations and Deployment Descriptors
Environment entries may be declared by use of annotations, without need for any deployment descriptor entries. Environment entries may also be declared by deployment descriptor entries. The same environment entry may be declared using both an annotation and a deployment descriptor entry. In this case, the information in the deployment descriptor entry may be used to override some of the information provided in the annotation. This approach may be used by an Application Assembler or Deployer to override information provided by the Application Component Developer. Applications should not use deployment descriptor entries to request injection of a resource into a field or method that has not been designed for injection.
The following list describes the rules for how a deployment descriptor entry may override a Resource annotation.
-
The relevant deployment descriptor entry is located based on the JNDI name used with the annotation (either defaulted or provided explicitly).
-
The type specified in the deployment descriptor must be assignable to the type of the field or property.
-
The description, if specified, overrides the description element of the annotation.
-
The injection target, if specified, defines additional injection points for the resource.
-
The mapped-name element, if specified, overrides the mappedName element of the annotation.
-
The res-sharing-scope element, if specified, overrides the shareable element of the annotation. In general, the Application Assembler or Deployer should not change this value as doing so is likely to break the application.
-
The res-auth element, if specified, overrides the authenticationType element of the annotation. In general, the Application Assembler or Deployer should not change this value as doing so is likely to break the application.
-
The lookup-name element, if specified, overrides the lookup element of the annotation.
It is an error to request injection of two resources into the same target. The behavior of an application that does so is undefined.
The rules for how a deployment descriptor entry may override an EJB annotation are included in the Jakarta Enterprise Beans specification. The rules for how a deployment descriptor entry may override a WebServiceRef annotation are included in the Web Services for Jakarta EE specification.
A PostConstruct method may be specified using either the PostConstruct annotation on the method or the post-construct deployment descriptor entry. Similarly, a PreDestroy method may be specified using either the PreDestroy annotation on the method or the pre-destroy deployment descriptor entry.
5.2.7. Other Naming Context Entries
In addition to environment entries declared by application components, other items will appear in the naming context, as specified by this and other specifications. Following are some of these entries. This is not an exhaustive list; consult the corresponding specification for details.
-
All enterprise beans in an application are given entries in the shared namespaces. See the Jakarta Enterprise Beans specification for details.
-
All web applications are given names in the shared namespaces. The names correspond to the complete URL of the web application. See the Servlet specification for details.
-
Objects representing several container services are defined in the java:comp namespace. See, for example, UserTransaction References,” TransactionSynchronizationRegistry References,” and ORB References.”
-
Strings providing the current module name and application name are defined in the java:comp namespace. See Application Name and Module Name References.”
5.3. Responsibilities by Jakarta EE Role
This section describes the responsibilities for each Jakarta EE role that apply to all uses of the Jakarta EE naming context. The sections that follow describe the responsibilities that are specific to the different types of objects that may be stored in the naming context.
5.3.1. Application Component Provider’s Responsibilities
The Application Component Provider may make use of three techniques for accessing and managing the naming context. First, the Application Component Provider may use Java language annotations to request injection of a resource from the naming context, or to declare elements that are needed in the naming context. Second, the component may use the JNDI APIs to access entries in the naming context. Third, deployment descriptor entries may be used to declare entries needed in the naming context, and to request injection of these entries into application components. Deployment descriptor entries may also be used to override information provided by annotations.
As part of the declaration of elements in the naming context, the Application Component Provider can specify the JNDI name of a resource to be looked up in the naming context to initialize the element being declared. The JNDI name in question may belong to any of the namespaces that compose the application component environment.
To ensure that it has access to the correct javax.naming.InitialContext implementation provided by the container, a portable application component must not specify the java.naming.factory.initial property, must not specify a URLContextFactory for the “java” scheme-id, and must not call the javax.naming.spi.NamingManager.setInitialContextFactoryBuilder method.
5.3.2. Application Assembler’s Responsibilities
The Application Assembler is allowed to modify the entries in the naming context set by the Application Component Provider, and is allowed to set the values of those entries for which the Application Component Provider has not specified any values. The Application Assembler may use the deployment descriptor to override settings made by the Application Component Provider in the source code using annotations.
5.3.3. Deployer’s Responsibilities
The Deployer must ensure that all the entries declared by an application component are created and properly initialized.
The Deployer can modify the entries that have been previously set by the Application Component Provider and/or Application Assembler, and must set the values of those entries for which a required value has not been specified. If an annotation contains the lookup element or a deployment descriptor entry includes the lookup-name element, the Deployer should bind it to the entry specified as the target of the lookup. Deployment should fail if the lookup element of an annotation or the lookup-name element in a deployment descriptor entry does not specify a name with an explicit java: namespace. The Deployer may also use product-specific resource mapping tools, deployment descriptors, rules, or capabilities to bind resource reference entries to resources in the target operational environment.
The description deployment descriptor elements and annotation elements provided by the Application Component Provider or Application Assembler help the Deployer with this task.
5.3.4. Jakarta EE Product Provider’s Responsibilities
The Jakarta EE Product Provider has the following responsibilities:
-
Provide a deployment tool that allows the Deployer to set and modify the entries of the application component’s naming context.
-
Implement the java:comp , java:module , java:app and java:global environment naming contexts, and provide them to the application component instances at runtime. The naming context must include all the entries declared by the Application Component Provider, with their values supplied in the deployment descriptor or set by the Deployer. The environment naming context must allow the Deployer to create subcontexts if they are needed by an application component. Certain entries in the naming context may have to be initialized with the values of other entries, specifically when the “lookup” facility is used. In this case, it is an error if there are any circular dependencies between entries. Similarly, it is an error if looking up the specified JNDI name results in a resource whose type is not compatible with the entry being created. The deployment tool may allow the deployer to correct either of these classes of errors and continue the deployment.
-
Ensure that, in the absence of any properties specified by the application, the javax.naming.InitialContext implementation meets the requirements described in this specification.
-
Inject entries from the naming environment into the application component, as specified by the deployment descriptor or annotations on the application component classes.
-
The container must ensure that the application component instances have only read access to their naming context. The container must throw the javax.naming.OperationNotSupportedException from all the methods of the javax.naming.Context interface that modify the environment naming context and its subcontexts.
5.4. Simple Environment Entries
A simple environment entry is a configuration parameter used to customize an application component’s business logic. The environment entry values may be one of the following Java types: String , Character , Byte , Short , Integer , Long , Boolean , Double , Float , Class , and any subclass of Enum .
The following subsections describe the responsibilities of each Jakarta EE Role.
5.4.1. Application Component Provider’s Responsibilities
This section describes the Application Component Provider’s view of the application component’s environment, and defines his or her responsibilities. It does so in three sections, the first describing annotations for injecting environment entries, the second describing the API for accessing environment entries, and the third describing syntax for declaring the environment entries in a deployment descriptor.
Injection of Simple Environment Entries
A field or a method of an application component may be annotated with the Resource annotation. The name and type of the environment entry are as described above. Note that the container will unbox the environment entry as required to match it to a primitive type used for the injection field or method. The authenticationType and shareable elements of the Resource annotation must not be specified; simple environment entries are not shareable and do not require authentication.
The following code example illustrates how an application component uses annotations to declare environment entries.
// The maximum number of tax exemptions, configured by the Deployer.
@Resource int maxExemptions;
// The minimum number of tax exemptions, configured by the Deployer.
@Resource int minExemptions;
public void setTaxInfo(int numberOfExemptions,...)
throws InvalidNumberOfExemptionsException {
...
// Use the environment entries to
// customize business logic.
if (numberOfExemptions > maxExemptions ||
numberOfExemptions < minExemptions)
throw new InvalidNumberOfExemptionsException();
...
}
The following code example illustrates how an environment entry can be assigned a value by referring to another entry, potentially in a different namespace.
// an entry that gets its value from an application-wide entry
@Resource(lookup="java:app/env/timeout") int timeout;
Programming Interfaces for Accessing Simple Environment Entries
In addition to the injection based approach described above, an application component may access environment entries dynamically. An application component instance locates the environment naming context using the JNDI interfaces. An instance creates a javax.naming.InitialContext object by using the constructor with no arguments, and looks up the naming environment via the InitialContext under the name java:comp/env . The application component’s environment entries are stored directly in the environment naming context, or in its direct or indirect subcontexts.
Environment entries have the Java programming language type declared by the Application Component Provider in the deployment descriptor.
The following code example illustrates how an application component accesses its environment entries.
public void setTaxInfo(int numberOfExemptions,...)
throws InvalidNumberOfExemptionsException {
...
// Obtain the application component’s
// environment naming context.
Context initCtx = new InitialContext();
Context myEnv = (Context)initCtx.lookup("java:comp/env");
// Obtain the maximum number of tax exemptions
// configured by the Deployer.
Integer max = (Integer)myEnv.lookup("maxExemptions");
// Obtain the minimum number of tax exemptions
// configured by the Deployer.
Integer min = (Integer)myEnv.lookup("minExemptions");
// Use the environment entries to
// customize business logic.
if (numberOfExemptions > max.intValue() ||
numberOfExemptions < min.intValue())
throw new InvalidNumberOfExemptionsException();
// Get some more environment entries. These environment
// entries are stored in subcontexts.
String val1 = (String)myEnv.lookup("foo/name1");
Boolean val2 = (Boolean)myEnv.lookup("foo/bar/name2");
// The application component can also
// lookup using full pathnames.
Integer val3 = (Integer)initCtx.lookup("java:comp/env/name3");
Integer val4 = (Integer)initCtx.lookup("java:comp/env/foo/name4");
...
}
Declaration of Simple Environment Entries
The Application Component Provider must declare all the environment entries accessed from the application component’s code. The environment entries are declared using either annotations on the application component’s code, or using the env-entry elements in the deployment descriptor. Each env-entry element describes a single environment entry. The env-entry element consists of an optional description of the environment entry, the environment entry name, which by default is relative to the java:comp/env context, the expected Java programming language type of the environment entry value (the type of the object returned from the JNDI lookup method), and an optional environment entry value.
An environment entry is scoped to the application component whose declaration contains the env-entry element. This means that the environment entry is not accessible from other application components at runtime, and that other application components may define env-entry elements with the same env-entry-name without causing a name conflict.
If the Application Component Provider provides a value for an environment entry using the env-entry-value element, the value can be changed later by the Application Assembler or Deployer. The value must be a string that is valid for the constructor of the specified type that takes a single String parameter, or in the case of Character , a single character.
The following example is the declaration of environment entries used by the application component whose code was illustrated in the previous subsection.
...
<env-entry>
<description>
The maximum number of tax exemptions
allowed to be set.
</description>
<env-entry-name>maxExemptions</env-entry-name>
<env-entry-type>java.lang.Integer</env-entry-type>
<env-entry-value>15</env-entry-value>
</env-entry>
<env-entry>
<description>
The minimum number of tax exemptions allowed to
be set.
</description>
<env-entry-name>minExemptions</env-entry-name>
<env-entry-type>java.lang.Integer</env-entry-type>
<env-entry-value>1</env-entry-value>
</env-entry>
<env-entry>
<env-entry-name>foo/name1</env-entry-name>
<env-entry-type>java.lang.String</env-entry-type>
<env-entry-value>value1</env-entry-value>
</env-entry>
<env-entry>
<env-entry-name>foo/bar/name2</env-entry-name>
<env-entry-type>java.lang.Boolean</env-entry-type>
<env-entry-value>true</env-entry-value>
</env-entry>
<env-entry>
<description>Some description.</description>
<env-entry-name>name3</env-entry-name>
<env-entry-type>java.lang.Integer</env-entry-type>
</env-entry>
<env-entry>
<env-entry-name>foo/name4</env-entry-name>
<env-entry-type>java.lang.Integer</env-entry-type>
<env-entry-value>10</env-entry-value>
</env-entry>
<env-entry>
<env-entry-name>helperClass</env-entry-name>
<env-entry-type>java.lang.Class</env-entry-type>
<env-entry-value>com.acme.helper.Helper</env-entry-value>
</env-entry>
<env-entry>
<env-entry-name>timeUnit</env-entry-name>
<env-entry-type>java.util.concurrent.TimeUnit</env-entry-type>
<env-entry-value>NANOSECONDS</env-entry-value>
</env-entry>
<env-entry>
<env-entry-name>bar</env-entry-name>
<env-entry-type>java.lang.Integer</env-entry-type>
<lookup-name>java:app/env/appBar</lookup-name>
</env-entry>
...
Injection of environment entries may also be specified using the deployment descriptor, without need for Java language annotations. The following example is the declaration of environment entries corresponding to the earlier injection example.
...
<env-entry>
<description>
The maximum number of tax exemptions
allowed to be set.
</description>
<env-entry-name>
com.example.PayrollService/maxExemptions
</env-entry-name>
<env-entry-type>java.lang.Integer</env-entry-type>
<env-entry-value>15</env-entry-value>
<injection-target>
<injection-target-class>
com.example.PayrollService
</injection-target-class>
<injection-target-name>
maxExemptions
</injection-target-name>
</injection-target>
</env-entry>
<env-entry>
<description>
The minimum number of tax exemptions
allowed to be set.
</description>
<env-entry-name>
com.example.PayrollService/minExemptions
</env-entry-name>
<env-entry-type>java.lang.Integer</env-entry-type>
<env-entry-value>1</env-entry-value>
<injection-target>
<injection-target-class>
com.example.PayrollService
</injection-target-class>
<injection-target-name>
minExemptions
</injection-target-name>
</injection-target>
</env-entry>
...
It’s often convenient to declare a field or method as an injection target, but specify a default value in the code, as illustrated in the following example.
// The maximum number of tax exemptions, configured by the Deployer.
@Resource int maxExemptions = 4; // defaults to 4
To support this case, the container must only inject a value for this resource if the deployer has specified a value to override the default value. The env-entry-value element in the deployment descriptor is optional when an injection target is specified. If the element is not specified, no value will be injected. In addition, if the element is not specified, the named resource is not initialized in the naming context; explicit lookups of the named resource will fail.
The deployment descriptor equivalent of the lookup element of the @Resource annotation is lookup-name . The following deployment descriptor fragment is equivalent to the earlier example that used lookup .
<env-entry>
<env-entry-name>somePackage.SomeClass/timeout</env-entry-name>
<env-entry-type>java.lang.Integer</env-entry-type>
<injection-target>
<injection-target-class>
somePackage.SomeClass
</injection-target-class>
<injection-target-name>timeout</injection-target-name>
</injection-target>
<lookup-name>java:app/env/timeout</lookup-name>
</env-entry>
It is an error for both the env-entry-value and lookup-name elements to be specified for a given env-entry element. If either element exists, an eventual lookup element of the corresponding Resource annotation (if any) must be ignored. In other words, assignment of a value to an environment entry via a deployment descriptor, either directly ( env-entry-value ) or indirectly ( lookup-name ), overrides any assignments made via annotations.
5.5. Jakarta Enterprise Beans References
This section describes the programming and deployment descriptor interfaces that allow the Application Component Provider to refer to the homes of enterprise beans or to enterprise bean instances using “logical” names called Jakarta Enterprise Beans references. The Jakarta Enterprise Beans references are special entries in the application component’s naming environment. The Deployer binds the Jakarta Enterprise Beans reference to the enterprise bean’s business interface, no-interface view, or home interface in the target operational environment.
The deployment descriptor also allows the Application Assembler to link a Jakarta Enterprise Bean reference declared in one application component to an enterprise bean contained in an ejb-jar file in the same Jakarta EE application. The link is an instruction to the tools used by the Deployer describing the binding of the Jakarta Enterprise Beans reference to the business interface, no-interface view, or home interface of the specified target enterprise bean. The same linking can also be specified by the Application Component Provider using annotations in the source code of the component.
The requirements in this section only apply to Jakarta EE products that include a Jakarta Enterprise Beans container.
5.5.1. Application Component Provider’s Responsibilities
This subsection describes the Application Component Provider’s view and responsibilities with respect to Jakarta Enterprise Beans references. It does so in three sections, the first describing annotations for injecting Jakarta Enterprise Beans references, the second describing the API for accessing Jakarta Enterprise Beans references, and the third describing the syntax for declaring the Jakarta Enterprise Beans references in a deployment descriptor
5.5.1.1. Injection of Jakarta Enterprise Beans Entries
A field or a method of an application component may be annotated with the EJB annotation. The EJB annotation represents a reference to a Jakarta Enterprise Beans session bean or entity bean. The reference may be to a session bean’s business interface, to a session bean’s no-interface view, or to the local or remote home interface of a session bean or entity bean.
The following example illustrates how an application component uses the EJB annotation to reference an instance of an enterprise bean. The referenced bean is a stateful session bean. The enterprise bean reference will have the name java:comp/env/com.example.ExampleBean/myCart in the naming context, where ExampleBean is the name of the class of the referencing bean and com.acme.example is its package. The target of the reference is not named and must be resolved by the Deployer, unless there is only one session bean component within the application that exposes a client view type that matches the Jakarta Enterprise Bean reference.
package com.acme.example;
@Stateless public class ExampleBean implements Example {
...
@EJB private ShoppingCart myCart;
...
}
The following example illustrates use of almost all elements of the EJB annotation.
@EJB(
name = "ejb/shopping-cart",
beanName = "cart1",
beanInterface = ShoppingCart.class,
description = "The shopping cart for this application"
)
private ShoppingCart myCart;
As an alternative to beanName , a reference to an enterprise bean can use the global JNDI name for that enterprise bean, or any of the other names mandated by the Jakarta Enterprise Beans specifications, by means of the lookup annotation element. The following example uses a JNDI name in the application namespace.
@EJB(
lookup="java:app/cartModule/ShoppingCart",
description = "The shopping cart for this application"
)
private ShoppingCart myOtherCart;
If the ShoppingCart bean were instead written to the Jakarta Enterprise Beans 2.x client view, the Jakarta Enterprise Bean reference would be to the bean’s home interface. For example:
@EJB(
name="ejb/shopping-cart",
beanInterface=ShoppingCartHome.class,
beanName="cart1",
description="The shopping cart for this application"
)
private ShoppingCartHome myCartHome;
If the ShoppingCart bean were instead written to the no-interface client view and implemented by bean class ShoppingCartBean.class , the Jakarta Enterprise Bean reference would have type ShoppingCartBean.class . For example:
@EJB(
name="ejb/shopping-cart",
beanInterface=ShoppingCartBean.class,
beanName="cart1",
description="The shopping cart for this application"
)
private ShoppingCartBean myCart;
5.5.1.2. Programming Interfaces for Jakarta Enterprise Beans References
The Application Component Provider may use Jakarta Enterprise Beans references to locate the business interface, no-interface view, or home interface of an enterprise bean as follows.
-
Assign an entry in the application component’s environment to the reference. (See subsection Declaration of Jakarta Enterprise Beans References for information on how Jakarta Enterprise Beans references are declared in the deployment descriptor.)
-
This specification recommends, but does not require, that references to enterprise beans be organized in the ejb subcontext of the application component’s environment (that is, in the java:comp/env/ejb JNDI context). Note that enterprise bean references declared via annotations will not, by default, be in any subcontext.
-
Look up the business interface, no-interface view, or home interface of the referenced enterprise bean in the application component’s environment using JNDI.
The following example illustrates how an application component uses a Jakarta Enterprise Bean reference to locate the home interface of an enterprise bean.
public void changePhoneNumber(...) {
...
// Obtain the default initial JNDI context.
Context initCtx = new InitialContext();
// Look up the home interface of the EmployeeRecord
// enterprise bean in the environment.
Object result = initCtx.lookup("java:comp/env/ejb/EmplRecord");
// Convert the result to the proper type.
EmployeeRecordHome emplRecordHome = (EmployeeRecordHome)
javax.rmi.PortableRemoteObject.narrow(result,
EmployeeRecordHome.class);
...
}
In the example, the Application Component Provider assigned the environment entry ejb/EmplRecord as the Jakarta Enterprise Bean reference name to refer to the remote home interface of an enterprise bean.
5.5.1.3. Declaration of Jakarta Enterprise Beans References
Although the Jakarta Enterprise Bean reference is an entry in the application component’s environment, the Application Component Provider must not use a env-entry element to declare it. Instead, the Application Component Provider must declare all the Jakarta Enterprise Beans references using either annotations on the application component’s code or the ejb-ref or ejb-local-ref elements of the deployment descriptor. This allows the consumer of the application component’s JAR file (the Application Assembler or Deployer) to discover all the Jakarta Enterprise Beans references used by the application component. Deployment descriptor entries may also be used to specify injection of a Jakarta Enterprise Bean reference into an application component.
Each ejb-ref or ejb-local-ref element describes the interface requirements that the referencing application component has for the referenced enterprise bean. The ejb-ref element is used for referencing an enterprise bean that is accessed through its remote business interface or remote home and component interfaces. The ejb-local-ref element is used for referencing an enterprise bean that is accessed through its local business interface, no-interface view, or local home and component interfaces. The ejb-ref element contains a description element and the ejb-ref-name , ejb-ref-type , home , and remote elements. The ejb-local-ref element contains a description element and the ejb-ref-name , ejb-ref-type , local-home , and local elements
The ejb-ref-name element specifies the Jakarta Enterprise Bean reference name. Its value is the environment entry name used in the application component code. The optional ejb-ref-type element specifies the expected type of the enterprise bean. Its value must be either Entity or Session . The home and remote or local-home and local elements specify the expected Java programming language types of the referenced enterprise bean’s interface(s). If the reference is to a Jakarta Enterprise Beans 2.x remote client view interface, the home element is required. Likewise, if the reference is to a Jakarta Enterprise Beans 2.x local client view interface, the local-home element is required. The remote element of the ejb-ref element refers to either the business interface type or the component interface, depending on whether the reference is to a bean’s Jakarta Enterprise Beans 3.x or Jakarta Enterprise Beans 2.x remote client view. Likewise, the local element of the ejb-local-ref element refers to either the business interface type, bean class type, or the component interface type, depending on whether the reference is to a bean’s Jakarta Enterprise Beans 3.x local business interface, no-interface view, or Jakarta Enterprise Beans 2.x local client view respectively.
A Jakarta Enterprise Bean reference is scoped to the application component whose declaration contains the ejb-ref or ejb-local-ref element. This means that the Jakarta Enterprise Bean reference is not accessible from other application components at runtime and that other application components may define ejb-ref or ejb-local-ref elements with the same ejb-ref-name without causing a name conflict.
The lookup-name element specifies the JNDI name of an environment entry that provides a value for the reference.
The following example illustrates the declaration of Jakarta Enterprise Beans references in the deployment descriptor.
...
<ejb-ref>
<description>
This is a reference to the entity bean that
encapsulates access to employee records.
</description>
<ejb-ref-name>ejb/EmplRecord</ejb-ref-name>
<ejb-ref-type>Entity</ejb-ref-type>
<home>com.wombat.empl.EmployeeRecordHome</home>
<remote>com.wombat.empl.EmployeeRecord</remote>
</ejb-ref>
<ejb-ref>
<ejb-ref-name>ejb/Payroll</ejb-ref-name>
<ejb-ref-type>Entity</ejb-ref-type>
<home>com.aardvark.payroll.PayrollHome</home>
<remote>com.aardvark.payroll.Payroll</remote>
</ejb-ref>
<ejb-ref>
<ejb-ref-name>ejb/PensionPlan</ejb-ref-name>
<ejb-ref-type>Session</ejb-ref-type>
<home>com.wombat.empl.PensionPlanHome</home>
<remote>com.wombat.empl.PensionPlan</remote>
<lookup-name>java:global/personnel/retirement/PensionPlan</lookup-name>
</ejb-ref>
...
5.5.2. Application Assembler’s Responsibilities
The Application Assembler can use the ejb-link element in the deployment descriptor to link a Jakarta Enterprise Beans reference to a target enterprise bean.
The Application Assembler specifies the link to an enterprise bean as follows:
-
The Application Assembler uses the optional ejb-link element of the ejb-ref or ejb-local-ref element of the referencing application component. The value of the ejb-link element is the name of the target enterprise bean. This is the name as defined by the metadata annotation (or default) on the bean class or in the ejb-name element for the target enterprise bean. The target enterprise bean can be in any ejb-jar file or war file in the same Jakarta EE application as the referencing application component.
-
Alternatively, to avoid the need to rename enterprise beans to have unique names within an entire Jakarta EE application, the Application Assembler may use either of the following two syntaxes in the ejb-link element of the referencing application component.
-
The Application Assembler specifies the module name of the ejb-jar file or war file containing the referenced enterprise bean and appends the ejb-name of the target bean separated by “/”. The module name is the base name of the bundle with no filename extension, unless specified in the deployment descriptor.
-
The Application Assembler specifies the path name of the ejb-jar file containing the referenced enterprise bean and appends the ejb-name of the target bean separated from the path name by “ # ”. The path name is relative to the referencing application component JAR file. In this manner, multiple beans with the same ejb-name may be uniquely identified when the Application Assembler cannot change _ejb-name_s.
-
Alternatively to the use of ejb-link , the Application Assembler may use the lookup-name element to reference the target enterprise bean component by means of one of its JNDI names. It is an error for both ejb-link and lookup-name to appear inside an ejb-ref element.
-
The Application Assembler must ensure that the target enterprise bean is type-compatible with the declared Jakarta Enterprise Beans reference. This means that the target enterprise bean must be of the type indicated in the ejb-ref-type element, if present, and that the business interface, no-interface view, or home and remote interfaces of the target enterprise bean must be Java type-compatible with the type declared in the Jakarta Enterprise Bean reference.
The following example illustrates the use of the ejb-link element in the deployment descriptor. The enterprise bean reference should be satisfied by the bean named EmployeeRecord . The EmployeeRecord enterprise bean may be packaged in the same module as the component making this reference, or it may be packaged in another module within the same Jakarta EE application as the component making this reference.
...
<ejb-ref>
<description>
This is a reference to the entity bean that
encapsulates access to employee records. It
has been linked to the entity bean named
EmployeeRecord in this application.
</description>
<ejb-ref-name>ejb/EmplRecord</ejb-ref-name>
<ejb-ref-type>Entity</ejb-ref-type>
<home>com.wombat.empl.EmployeeRecordHome</home>
<remote>com.wombat.empl.EmployeeRecord</remote>
<ejb-link>EmployeeRecord</ejb-link>
</ejb-ref>
...
The following example illustrates using the ejb-link element to indicate an enterprise bean reference to the ProductEJB enterprise bean that is in the same Jakarta EE application unit but in a different ejb-jar file.
...
<ejb-ref>
<description>
This is a reference to the entity bean that
encapsulates access to a product. It
has been linked to the entity bean named
ProductEJB in the product.jar file in this
application.
</description>
<ejb-ref-name>ejb/Product</ejb-ref-name>
<ejb-ref-type>Entity</ejb-ref-type>
<home>com.acme.products.ProductHome</home>
<remote>com.acme.products.Product</remote>
<ejb-link>../products/product.jar#ProductEJB</ejb-link>
</ejb-ref>
...
The following example illustrates using the ejb-link element to indicate an enterprise bean reference to the ShoppingCart enterprise bean that is in the same Jakarta EE application unit but in a different ejb-jar file. The reference was originally declared in the application component’s code using an annotation. The Assembler provides only the link to the bean.
...
<ejb-ref>
<ejb-ref-name>ShoppingService/myCart</ejb-ref-name>
<ejb-link>../products/product.jar#ShoppingCart</ejb-link>
</ejb-ref>
...
The same effect can be obtained by using the lookup-name element instead, using an appropriate JNDI name for the target bean.
...
<ejb-ref>
<ejb-ref-name>ShoppingService/myCart</ejb-ref-name>
<lookup-name>java:app/products/ShoppingCart</lookup-name>
</ejb-ref>
...
5.5.3. Deployer’s Responsibilities
The Deployer is responsible for the following:
-
The Deployer must ensure that all the declared Jakarta Enterprise Beans references are bound to the business interfaces, no-interface views, or home interfaces of enterprise beans that exist in the operational environment. The Deployer may use, for example, the JNDI LinkRef mechanism to create a symbolic link to the actual JNDI name of the target enterprise bean.
-
The Deployer must ensure that the target enterprise bean is type-compatible with the types declared for the Jakarta Enterprise Bean reference. This means that the target enterprise bean must be of the type indicated in the ejb-ref-type element or specified via the EJB annotation, and that the business interface, no-interface view, or home and remote interfaces of the target enterprise bean must be Java type-compatible with the type declared in the Jakarta Enterprise Bean reference (if specified).
-
If a Jakarta Enterprise Bean reference declaration includes the ejb-link element, the Deployer should bind the enterprise bean reference to the enterprise bean specified as the link’s target. If an EJB annotation includes the lookup element or the Jakarta Enterprise Beans reference declaration includes the lookup-name element, the Deployer should bind the enterprise bean reference to the enterprise bean specified as the target of the lookup. It is an error for a Jakarta Enterprise Bean reference declaration to include both an ejb-link and a lookup-name element.
The following example illustrates the use of the lookup-name element to bind an ejb-ref to a target enterprise bean in the operational environment. The reference was originally declared in the bean’s code using an annotation. The target enterprise bean has ejb-name ShoppingCart and is deployed in the stand-alone module products.jar .
...
<ejb-ref>
<ejb-ref-name>ShoppingService/myCart</ejb-ref-name>
<lookup-name>java:global/products/ShoppingCart</lookup-name>
</ejb-ref>
5.5.4. Jakarta EE Product Provider’s Responsibilities
The Jakarta EE Product Provider must provide the deployment tools that allow the Deployer to perform the tasks described in the previous subsection. The deployment tools provided by the Jakarta EE Product Provider must be able to process the information supplied in class file annotations and in the ejb-ref and ejb-local-ref elements in the deployment descriptor.
At the minimum, the tools must be able to:
-
Preserve the application assembly information in annotations or in the ejb-link elements by binding a Jakarta Enterprise Bean reference to the business interface, no-interface view, or home interface of the specified target enterprise bean.
-
Inform the Deployer of any unresolved Jakarta Enterprise Beans references, and allow him or her to resolve a Jakarta Enterprise Bean reference by binding it to a specified compatible target enterprise bean.
5.6. Web Service References
A web service reference is similar to an Jakarta Enterprise Bean reference, but is used to reference a web service. Web service references are fully specified in the Web Service specification and the JAX-WS specification.
5.7. Resource Manager Connection Factory References
A resource manager connection factory is an object that is used to create connections to a resource manager. For example, an object that implements the javax.sql.DataSource interface is a resource manager connection factory for java.sql.Connection objects that implement connections to a database management system.
This section describes the application component programming and deployment descriptor interfaces that allow the application component code to refer to resource factories using logical names called resource manager connection factory references. The resource manager connection factory references are special entries in the application component’s environment. The Deployer binds the resource manager connection factory references to the actual resource manager connection factories that exist in the target operational environment. Because these resource manager connection factories allow the Container to affect resource management, the connections acquired through the resource manager connection factory references are called managed resources (for example, these resource manager connection factories allow the Container to implement connection pooling and automatic enlistment of the connection with a transaction).
Resource manager connection factory objects accessed through the naming environment are only valid within the component instance that performed the lookup. See the individual component specifications for additional restrictions that may apply.
5.7.1. Application Component Provider’s Responsibilities
This subsection describes the Application Component Provider’s view of locating resource factories and defines his or her responsibilities. It does so in three sections, the first describing the annotations used to inject resource manager connection factory references, the second describing the API for accessing resource manager connection factory references, and the third describing the syntax for declaring the factory references in a deployment descriptor
5.7.1.1. Injection of Resource Manager Connection Factory References
A field or a method of an application component may be annotated with the Resource annotation. The name and type of the factory are as described above. The authenticationType and shareable elements of the Resource annotation may be used to control the type of authentication desired for the resource and the shareability of connection acquired from the factory, as described in the following sections.
The following code example illustrates how an application component uses annotations to declare resource manager connection factory references.
// The employee database.
@Resource javax.sql.DataSource employeeAppDB;
public void changePhoneNumber(...) {
...
// Invoke factory to obtain a resource. The security
// principal for the resource is not given, and
// therefore it will be configured by the Deployer.
java.sql.Connection con = employeeAppDB.getConnection();
...
}
It is possible to specify as part of the @Resource annotation the JNDI name of an entry to which the resource being defined will be bound.
// The customer database, looked up in the application environment.
@Resource(lookup="java:app/env/customerDB")
javax.sql.DataSource customerAppDB;
The data source object being looked up in the previous example may have been declared as follows.
@Resource(name="java:app/env/customerDB",
type=javax.sql.DataSource.class)
public class AnApplicationClass {
...
}
From a practical standpoint, declaring a commonly used data source at the application level and referring to it using lookup from multiple components may simplify the task of deploying the application, since now the Deployer will have to perform a single binding operation for the application-level resource, instead of multiple ones. The task can be further simplified by using a data source resource definition, see DataSource Resource Definition”. Of course, nothing prevents the Deployer from separately binding each data source reference if necessary.
5.7.1.2. Programming Interfaces for Resource Manager Connection Factory References
The Application Component Provider may use resource manager connection factory references to obtain connections to resources as follows.
-
Assign an entry in the application component’s naming environment to the resource manager connection factory reference. (See subsection Declaration of Resource Manager Connection Factory References in Deployment Descriptor for information on how resource manager connection factory references are declared in the deployment descriptor.)
-
This specification recommends, but does not require, that all resource manager connection factory references be organized in the subcontexts of the application component’s environment, using a different subcontext for each resource manager type. For example, all JDBC™ DataSource references should be declared in the java:comp/env/jdbc subcontext, all Jakarta Messaging connection factories in the java:comp/env/jms subcontext, all Jakarta Mail connection factories in the java:comp/env/mail subcontext, and all URL connection factories in the java:comp/env/url subcontext. Note that resource manager connection factory references declared via annotations will not, by default, appear in any subcontext.
-
Lookup the resource manager connection factory object in the application component’s environment using the JNDI interface.
-
Invoke the appropriate method on the resource manager connection factory object to obtain a connection to the resource. The factory method is specific to the resource type. It is possible to obtain multiple connections by calling the factory object multiple times.
The Application Component Provider can control the shareability of the connections acquired from the resource manager connection factory. By default, connections to a resource manager are shareable across other application components in the application that use the same resource in the same transaction context. The Application Component Provider can specify that connections obtained from a resource manager connection factory reference are not shareable by specifying the value of the shareable annotation element to false or the res-sharing-scope deployment descriptor element to be Unshareable . The sharing of connections to a resource manager allows the container to optimize the use of connections and enables the container’s use of local transaction optimizations.
The Application Component Provider has two choices with respect to dealing with associating a principal with the resource manager access:
-
Allow the Deployer to set up principal mapping or resource manager sign on information. In this case, the application component code invokes a resource manager connection factory method that has no security-related parameters.
-
Sign on to the resource from the application component code. In this case, the application component invokes the appropriate resource manager connection factory method that takes the sign on information as method parameters.
The Application Component Provider uses the authenticationType annotation element or the res-auth deployment descriptor element to indicate which of the two resource authentication approaches is used.
We expect that the first form (that is letting the Deployer set up the resource sign on information) will be the approach used by most application components.
The following code sample illustrates obtaining a JDBC connection.
public void changePhoneNumber(...) {
...
// obtain the initial JNDI context
Context initCtx = new InitialContext();
// perform JNDI lookup to obtain resource manager
// connection factory
javax.sql.DataSource ds = (javax.sql.DataSource)
initCtx.lookup("java:comp/env/jdbc/EmployeeAppDB");
// Invoke factory to obtain a resource. The security
// principal for the resource is not given, and
// therefore it will be configured by the Deployer.
java.sql.Connection con = ds.getConnection();
...
}
5.7.1.3. Declaration of Resource Manager Connection Factory References in Deployment Descriptor
Although a resource manager connection factory reference is an entry in the application component’s environment, the Application Component Provider must not use an env-entry element to declare it.
Instead, the Application Component Provider must declare all the resource manager connection factory references using either annotations on the application component’s code or in the deployment descriptor using the resource-ref elements. This allows the consumer of the application component’s JAR file (the Application Assembler or Deployer) to discover all the resource manager connection factory references used by an application component. Deployment descriptor entries may also be used to specify injection of a resource manager connection factory reference into an application component.
Each resource-ref element describes a single resource manager connection factory reference. The resource-ref element consists of the description element, the mandatory res-ref-name element, and the optional res-sharing-scope , res-type , and res-auth elements. The res-ref-name element contains the name of the environment entry used in the application component’s code. The name of the environment entry is relative to the java:comp/env context (for example, the name should be jdbc/EmployeeAppDB rather than java:comp/env/jdbc/EmployeeAppDB ). The res-type element contains the Java programming language type of the resource manager connection factory that the application component code expects. The res-type element is optional if an injection target is specified for this resource; in this case the res-type defaults to the type of the injection target. The res-auth element indicates whether the application component code performs resource sign on programmatically, or whether the container signs on to the resource based on the principal mapping information supplied by the Deployer. The Application Component Provider indicates the sign on responsibility by setting the value of the res-auth element to Application or Container . If not specified, the default is Container . The res-sharing-scope element indicates whether connections to the resource manager obtained through the given resource manager connection factory reference can be shared or whether connections are unshareable. The value of the res-sharing-scope element is Shareable or Unshareable . If the res-sharing-scope element is not specified, connections are assumed to be shareable.
A resource manager connection factory reference is scoped to the application component whose declaration contains the resource-ref element. This means that the resource manager connection factory reference is not accessible from other application components at runtime, and that other application components may define resource-ref elements with the same res-ref-name without causing a name conflict.
The type declaration allows the Deployer to identify the type of the resource manager connection factory.
Note that the indicated type is the Java programming language type of the resource manager connection factory, not the type of the connection.
The following example is the declaration of the resource reference used by the application component illustrated in the previous subsection.
...
<resource-ref>
<description>
A data source for the database in which
the EmployeeService enterprise bean will
record a log of all transactions.
</description>
<res-ref-name>jdbc/EmployeeAppDB</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
...
The following example modifies the previous one by linking the resource reference being defined to another one, using a well-known JNDI name for the latter.
<resource-ref>
<res-ref-name>jdbc/EmployeeAppDB</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
<lookup-name>java:app/env/TheEmployeeDB</lookup-name>
</resource-ref>
5.7.1.4. Standard Resource Manager Connection Factory Types
The Application Component Provider must use the javax.sql.DataSource resource manager connection factory type for obtaining JDBC API connections.
The Application Component Provider must use the javax.jms.ConnectionFactory , the javax.jms.QueueConnectionFactory , or the javax.jms.TopicConnectionFactory for obtaining Jakarta Messaging connections.
The Application Component Provider must use the javax.mail.Session resource manager connection factory type for obtaining Jakarta Mail API connections.
The Application Component Provider must use the java.net.URL resource manager connection factory type for obtaining URL connections.
It is recommended that the Application Component Provider name JDBC API data sources in the java:comp/env/jdbc subcontext, all Jakarta Messaging connection factories in the java:comp/env/jms subcontext, all Jakarta Mail API connection factories in the java:comp/env/mail subcontext, and all URL connection factories in the java:comp/env/url subcontext. Note that resource manager connection factory references declared via annotations will not, by default, appear in any subcontext.
The Jakarta EE Connector Architecture allows an application component to use the annotation or API described in this section to obtain resource objects that provide access to additional back-end systems.
5.7.2. Deployer’s Responsibilities
The Deployer uses deployment tools to bind the resource manager connection factory references to the actual resource factories configured in the target operational environment.
The Deployer must perform the following tasks for each resource manager connection factory reference declared in the deployment descriptor:
-
Bind the resource manager connection factory reference to a resource manager connection factory that exists in the operational environment. The Deployer may use, for example, the JNDI LinkRef mechanism to create a symbolic link to the actual JNDI name of the resource manager connection factory. The resource manager connection factory type must be compatible with the type declared in the source code or in the res-type element. If the resource manager connection factory references includes a lookup annotation element or a lookup-name deployment descriptor element, the Deployer may choose whether to honor it and have the corresponding lookup be performed, or override it with a binding of his or her own choosing.
-
Provide any additional configuration information that the resource manager needs for opening and managing the resource. The configuration mechanism is resource manager specific, and is beyond the scope of this specification.
-
If the value of the Resource annotation authenticationType element is AuthenticationType.CONTAINER or the deployment descriptor’s res-auth element is Container , the Deployer is responsible for configuring the sign on information for the resource manager. This is performed in a manner specific to the container and resource manager; it is beyond the scope of this specification.
For example, if principals must be mapped from the security domain and principal realm used at the application component level to the security domain and principal realm of the resource manager, the Deployer or System Administrator must define the mapping. The mapping is performed in a manner specific to the container and resource manager; it is beyond the scope of this specification.
5.7.3. Jakarta EE Product Provider’s Responsibilities
The Jakarta EE Product Provider is responsible for the following:
-
Provide the deployment tools that allow the Deployer to perform the tasks described in the previous subsection.
-
Provide the implementation of the resource manager connection factory classes that are required by this specification.
-
If the Application Component Provider sets the authenticationType element of the Resource annotation to AuthenticationType.APPLICATION or the res-auth of a resource reference to Application , the container must allow the application component to perform explicit programmatic sign on using the resource manager’s API.
-
If the Application Component Provider sets the shareable element of the Resource annotation to false or sets the res-sharing-scope of a resource manager connection factory reference to Unshareable , the container must not attempt to share the connections obtained from the resource manager connection factory reference.[12]
-
The container must provide tools that allow the Deployer to set up resource sign on information for the resource manager references whose authenticationType is set to AuthenticationType.CONTAINER or whose res-auth element is set to Container . The minimum requirement is that the Deployer must be able to specify the username/password information for each resource manager connection factory reference declared by the application component, and the container must be able to use the username/password combination for user authentication when obtaining a connection by invoking the resource manager connection factory.
Although not required by this specification, we expect that containers will support some form of a single sign on mechanism that spans the application server and the resource managers. The container will allow the Deployer to set up the resources such that the principal can be propagated (directly or through principal mapping) to a resource manager, if required by the application.
While not required by this specification, most Jakarta EE products will provide the following features:
-
A tool to allow the System Administrator to add, remove, and configure a resource manager for the Jakarta EE Server.
-
A mechanism to pool resources for the application components and otherwise manage the use of resources by the container. The pooling must be transparent to the application components.
5.8. Resource Environment References
This section describes the programming and deployment descriptor interfaces that allow the Application Component Provider to refer to administered objects that are associated with a resource (for example, a Connector CCI InteractionSpec instance) by using “logical” names called resource environment references. The resource environment references are special entries in the application component’s environment. The Deployer binds the resource environment references to administered objects in the target operational environment.
5.8.1. Application Component Provider’s Responsibilities
This subsection describes the Application Component Provider’s view and responsibilities with respect to resource environment references.
5.8.1.1. Injection of Resource Environment References
A field or a method of an application component may be annotated with the Resource annotation to request injection of a resouce environment reference. The name and type of the resource environment reference are as described earlier. The authenticationType and shareable elements of the Resource annotation must not be specified; resource environment entries are not shareable and do not require authentication. The use of the Resource annotation to declare a resource environment reference differs from the use of the Resource annotation to declare other environment references only in that the type of a resource environment reference is not one of the Java language types used for other environment references.
5.8.1.2. Resource Environment Reference Programming Interfaces
The Application Component Provider may use resource environment references to locate administered objects that are associated with resources as follows.
-
Assign an entry in the application component’s environment to the reference. (See subsection Declaration of Resource Environment References in Deployment Descriptor for information on how resource environment references are declared in the deployment descriptor.)
-
This specification recommends, but does not require, that all resource environment references be organized in the appropriate subcontext of the component’s environment for the resource type. Note that resource environment references declared via annotations will not, by default, appear in any subcontext.
-
Look up the administered object in the application component’s environment using JNDI.
5.8.1.3. Declaration of Resource Environment References in Deployment Descriptor
Although the resource environment reference is an entry in the application component’s environment, the Application Component Provider must not use a env-entry element to declare it. Instead, the Application Component Provider must declare all references to administered objects associated with resources using either annotations on the application component’s code or the resource-env-ref elements of the deployment descriptor. This allows the application component’s JAR file consumer to discover all the resource environment references used by the application component. Deployment descriptor entries may also be used to specify injection of a resource environment reference into an application component.
Each resource-env-ref element describes the requirements that the referencing application component has for the referenced administered object. The resource-env-ref element contains optional description and resource-env-ref-type elements and the mandatory resource-env-ref-name element. The resource-env-ref-type element is optional if an injection target is specified for this resource; in this case the resource-env-ref-type defaults to the type of the injection target.
The resource-env-ref-name element specifies the resource environment reference name. Its value is the environment entry name used in the application component code. The name of the resource environment reference is relative to the java:comp/env context. The resource-env-ref-type element specifies the expected type of the referenced object.
A resource environment reference is scoped to the application component whose declaration contains the resource-env-ref element. This means that the resource environment reference is not accessible to other application components at runtime, and that other application components may define resource-env-ref elements with the same resource-env-ref-name without causing a name conflict.
A resource environment reference may specify a lookup-name to link the reference being defined to another one via a JNDI name.
5.8.2. Deployer’s Responsibilities
The Deployer is responsible for the following:
-
The Deployer must ensure that all the declared resource environment references are bound to administered objects that exist in the operational environment. The Deployer may use, for example, the JNDI LinkRef mechanism to create a symbolic link to the actual JNDI name of the target object. The Deployer may override the linkage preferences of a resource environment reference that includes a lookup annotation element or lookup-name deployment descriptor element.
-
The Deployer must ensure that the target object is type-compatible with the type declared for the resource environment reference. This means that the target object must be of the type indicated in the Resource annotation or the resource-env-ref-type element.
5.8.3. Jakarta EE Product Provider’s Responsibilities
The Jakarta EE Product Provider must provide the deployment tools that allow the Deployer to perform the tasks described in the previous subsection. The deployment tools provided by the Jakarta EE Product Provider must be able to process the information supplied in the class file annotations and the resource-env-ref elements in the deployment descriptor.
At the minimum, the tools must be able to inform the Deployer of any unresolved resource environment references, and allow him or her to resolve a resource environment reference by binding it to a specified compatible target object in the environment.
5.9. Message Destination References
This section describes the programming and deployment descriptor interfaces that allow the Application Component Provider to refer to message destination objects by using “logical” names called message destination references. Message destination references are special entries in the application component’s environment. The Deployer binds the message destination references to administered message destinations in the target operational environment.
The requirements in this section only apply to Jakarta EE products that include support for Jakarta Messaging.
5.9.1. Application Component Provider’s Responsibilities
This subsection describes the Application Component Provider’s view and responsibilities with respect to message destination references.
5.9.1.1. Injection of Message Destination References
A field or a method of an application component may be annotated with the Resource annotation to request injection of a message destination reference. The name and type of the resource environment reference are as described earlier. The authenticationType and shareable elements of the Resource annotation must not be specified; message destination references are not shareable and do not require authentication.
Note that when using the Resource annotation to declare a message destination reference it is not possible to link the reference to other references to the same message destination or to specify whether the message destination is used to produce or consume messages. The deployment descriptor entries described later do provide a way to associate many message destination references with a single message destination and to specify whether each message destination reference is used to produce, consume, or both produce and consume messages, so that the entire message flow of an application may be specified. The Application Assembler may use these message destination links to link together message destination references that have been declared using the Resource annotation. A message destination reference declared via the Resource annotation is assumed to be used to both produce and consume messages; this default may be overridden using a deployment descriptor entry.
The following example illustrates how an application component uses the Resource annotation to request injection of a message destination reference.
@Resource javax.jms.Queue stockQueue;
The following example illustrates how a message destination reference can be linked to another one by specifying its JNDI name, perhaps in a different namespace, as a value for the lookup element.
@Resource(lookup="java:app/env/TheOrderQueue")
javax.jms.Queue orderQueue;
5.9.1.2. Message Destination Reference Programming Interfaces
The Application Component Provider may use message destination references to locate message destinations, as follows.
-
Assign an entry in the application component’s environment to the reference. (See subsection Declaration of Message Destination References in Deployment Descriptor for information on how message destination references are declared in the deployment descriptor.)
-
This specification recommends, but does not require, that all message destination references be organized in the appropriate subcontext of the component’s environment for the resource type (for example, in the java:comp/env/jms JNDI context for Jakarta Messaging Destinations). Note that message destination references declared via annotations will not, by default, appear in any subcontext.
-
Look up the administered object in the application component’s environment using JNDI.
The following example illustrates how an application component uses a message destination reference to locate a Jakarta Messaging Destination.
// Obtain the default initial JNDI context.
Context initCtx = new InitialContext();
// Look up the Jakarta Messaging StockQueue in the environment.
Object result = initCtx.lookup("java:comp/env/jms/StockQueue");
// Convert the result to the proper type.
javax.jms.Queue queue = (javax.jms.Queue)result;
In the example, the Application Component Provider assigned the environment entry jms/StockQueue as the message destination reference name to refer to a Jakarta Messaging queue.
5.9.1.3. Declaration of Message Destination References in Deployment Descriptor
Although the message destination reference is an entry in the application component’s environment, the Application Component Provider must not use a env-entry element to declare it. Instead, the Application Component Provider should declare all references to message destinations using either the Resource annotation in the application component’s code or the message-destination-ref elements of the deployment descriptor. This allows the application component’s JAR file consumer to discover all the message destination references used by the application component. Deployment descriptor entries may also be used to specify injection of a message destination reference into an application component.
Each message-destination-ref element describes the requirements that the referencing application component has for the referenced destination. The message-destination-ref element contains optional description , message-destination-type , and message-destination-usage elements and the mandatory message-destination-ref-name element.
The message-destination-ref-name element specifies the message destination reference name. Its value is the environment entry name used in the application component code. By default, the name of the message destination reference is relative to the java:comp/env context (for example, the name should be jms/StockQueue rather than java:comp/env/jms/StockQueue ). The message-destination-type element specifies the expected type of the referenced destination. For example, in the case of a Jakarta Messaging Destination, its value might be javax.jms.Queue . The message-destination-type element is optional if an injection target is specified for this message destination reference; in this case the message-destination-type defaults to the type of the injection target. The message-destination-usage element specifies whether messages are consumed from the message destination, produced for the destination, or both. If not specified, messages are assumed to be both consumed and produced.
A message destination reference is scoped to the application component whose declaration contains the message-destination-ref element. This means that the message destination reference is not accessible to other application components at runtime, and that other application components may define message-destination-ref elements with the same message-destination-ref-name without causing a name conflict.
The following example illustrates the declaration of message destination references in the deployment descriptor.
...
<message-destination-ref>
<description>
This is a reference to a Jakarta Messaging queue used in the
processing of Stock info
</description>
<message-destination-ref-name>
jms/StockInfo
</message-destination-ref-name>
<message-destination-type>
javax.jms.Queue
</message-destination-type>
<message-destination-usage>
Produces
</message-destination-usage>
</message-destination-ref>
...
5.9.2. Application Assembler’s Responsibilities
By means of linking message consumers and producers to one or more common logical destinations specified in the enterprise bean deployment descriptor, the Application Assembler can specify the flow of messages within an application. The Application Assembler uses the message-destination element, the message-destination-link element of the message-destination-ref element, and the message-destination-link element of an ejb-jar’s message-driven element to link message destination references to a common logical destination.
The Application Assembler specifies the link between message consumers and producers as follows:
-
The Application Assembler uses the message-destination element to specify a logical message destination within the application. The message-destination element defines a message-destination-name , which is used for the purpose of linking.
-
The Application Assembler uses the message-destination-link element of the message-destination-ref element of an application component that produces messages to link it to the target destination. The value of the message-destination-link element is the name of the target destination, as defined in the message-destination-name element of the message-destination element. The message-destination element can be in any module in the same Jakarta EE application as the referencing component. The Application Assembler uses the message-destination-usage element of the message-destination-ref element to indicate that the referencing application component produces messages to the referenced destination.
-
If the consumer of messages from the common destination is a message-driven bean, the Application Assembler uses the message-destination-link element of the message-driven element to reference the logical destination. If the Application Assembler links a message-driven bean to its source destination, he or she should use the message-destination-type element of the message-driven element to specify the expected destination type. Otherwise, the Application Assembler uses the message-destination-link element of the message-destination-ref element of the application component that consumes messages to link to the common destination. In the latter case, the Application Assembler uses the message-destination-usage element of the message-destination-ref element to indicate that the application component consumes messages from the referenced destination.
-
To avoid the need to rename message destinations to have unique names within an entire Jakarta EE application, the Application Assembler may use the following syntax in the message-destination-link element of the referencing application component. The Application Assembler specifies the path name of the JAR file containing the referenced message destination and appends the message-destination-name of the target destination separated from the path name by #. The path name is relative to the referencing application component JAR file. In this manner, multiple destinations with the same message-destination-name may be uniquely identified.
-
When linking message destinations, the Application Assembler must ensure that the consumers and producers for the destination require a message destination of the same or compatible type, as determined by the messaging system.
5.9.3. Deployer’s Responsibilities
The Deployer is responsible for the following:
-
The Deployer must ensure that all the declared message destination references are bound to administered objects that exist in the operational environment. The Deployer may use, for example, the JNDI LinkRef mechanism to create a symbolic link to the actual JNDI name of the target object. The Deployer may override the linkage preferences of a message destination reference that includes a lookup-name element.
-
The Deployer must ensure that the target object is type-compatible with the type declared for the message destination reference. This means that the target object must be of the type indicated in the message-destination-type element.
-
The Deployer must observe the message destination links specified by the Application Assembler.
5.9.4. Jakarta EE Product Provider’s Responsibilities
The Jakarta EE Product Provider must provide the deployment tools that allow the Deployer to perform the tasks described in the previous subsection. The deployment tools provided by the Jakarta EE Product Provider must be able to process the information supplied in the message-destination-ref elements in the deployment descriptor.
At the minimum, the tools must be able to inform the Deployer of any unresolved message destination references, and allow him or her to resolve a message destination reference by binding it to a specified compatible target object in the environment.
5.10. UserTransaction References
Certain Jakarta EE application component types are allowed to use the Jakarta Transactions UserTransaction interface to start, commit, and abort transactions. Such application components can find an appropriate object implementing the UserTransaction interface by looking up the JNDI name java:comp/UserTransaction or by requesting injection of a UserTransaction object using the Resource annotation. The authenticationType and shareable elements of the Resource annotation must not be specified. The container is only required to provide the java:comp/UserTransaction name, or inject a UserTransaction object, for those components that can validly make use of it. Any such reference to a UserTransaction object is only valid within the component instance that performed the lookup. See the individual component definitions for further information.
The following example illustrates how an application component acquires and uses a UserTransaction object via injection.
@Resource UserTransaction tx;
public void updateData(...) {
...
// Start a transaction.
tx.begin();
...
// Perform transactional operations on data.
...
// Commit the transaction.
tx.commit();
...
}
The following example illustrates how an application component acquires and uses a UserTransaction object using a JNDI lookup.
public void updateData(...) {
...
// Obtain the default initial JNDI context.
Context initCtx = new InitialContext();
// Look up the UserTransaction object.
UserTransaction tx = (UserTransaction)initCtx.lookup(
"java:comp/UserTransaction");
// Start a transaction.
tx.begin();
...
// Perform transactional operations on data.
...
// Commit the transaction.
tx.commit();
...
}
A UserTransaction object reference may also be declared in a deployment descriptor in the same way as a resource environment reference. Such a deployment descriptor entry may be used to specify injection of a UserTransaction object.
The requirements in this section only apply to Jakarta EE products that include support for Jakarta Transactions.
5.10.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for requesting injection of a UserTransaction object using a Resource annotation, or using the defined name to look up the UserTransaction object.
Only some application component types are required to be able to access a UserTransaction object; see Jakarta EE Technologies in this specification and the Jakarta Enterprise Beans specification for details.
5.11. TransactionSynchronizationRegistry References
The Jakarta Transactions TransactionSynchronizationRegistry interface may be used by system level components such as persistence managers that may be packaged with enterprise bean or web application components. Such components can find an appropriate object implementing the TransactionSynchronizationRegistry interface by looking up the JNDI name java:comp/TransactionSynchronizationRegistry or by requesting injection of a TransactionSynchronizationRegistry object using the Resource annotation. The authenticationType and shareable elements of the Resource annotation must not be specified. The container is only required to provide the java:comp/TransactionSynchronizationRegistry name, or inject a TransactionSynchronizationRegistry object, for those components that can validly make use of it. Any such reference to a TransactionSynchronizationRegistry object is only valid within the component instance that performed the lookup. See the individual component definitions for further information.
A TransactionSynchronizationRegistry object reference may also be declared in a deployment descriptor in the same way as a resource environment reference. Such a deployment descriptor entry may be used to specify injection of a TransactionSynchronizationRegistry object.
The requirements in this section only apply to Jakarta EE products that include support for Jakarta Transactions.
5.11.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for requesting injection of a TransactionSynchronizationRegistry object using a Resource annotation, or using the defined name to look up the TransactionSynchronizationRegistry object.
Only some application component types are required to be able to access a TransactionSynchronizationRegistry object; see Jakarta EE Technologies in this specification for details.
5.12. ORB References
Some Jakarta EE applications will need to make use of the CORBA ORB to perform certain operations. Such applications can find an appropriate object implementing the ORB interface by looking up the JNDI name java:comp/ORB or by requesting injection of an ORB object. The container is required to provide the java:comp/ORB name for all components except applets. Any such reference to a ORB object is only valid within the component instance that performed the lookup.
The following example illustrates how an application component acquires and uses an ORB object via injection.
@Resource ORB orb;
public void method(...) {
...
// Get the POA to use when creating object references.
POA rootPOA = (POA)orb.resolve_initial_references("RootPOA");
...
}
The following example illustrates how an application component acquires and uses an ORB object using a JNDI lookup.
public void method(...) {
...
// Obtain the default initial JNDI context.
Context initCtx = new InitialContext();
// Look up the ORB object.
ORB orb = (ORB)initCtx.lookup("java:comp/ORB");
// Get the POA to use when creating object references.
POA rootPOA = (POA)orb.resolve_initial_references("RootPOA");
...
}
An ORB object reference may also be declared in a deployment descriptor in the same way as a resource manager connection factory reference. Such a deployment descriptor entry may be used to specify injection of an ORB object.
The ORB instance available under the JNDI name java:comp/ORB may always be a shared instance. By default, the ORB instance injected into a component or declared via a deployment descriptor entry may also be a shared instance. However, the application may set the shareable element of the Resource annotation to false , or may set the res-sharing-scope element in the deployment descriptor to Unshareable , to request a non-shared ORB instance.
The requirements in this section only apply to Jakarta EE products that include support for interoperability using CORBA.
5.12.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for requesting injection of the ORB object using the Resource annotation, or using the defined name to look up the ORB object. If the shareable element of the Resource annotation is set to false , the ORB object injected will not be the shared instance used by other components in the application but instead will be a private ORB instance used only by this component.
5.13. Persistence Unit References
This section describes the metadata annotations and deployment descriptor elements that allow the application component code to refer to the entity manager factory for a persistence unit using a logical name called a persistence unit reference . Persistence unit references are special entries in the application component’s environment. The Deployer binds the persistence unit references to entity manager factories that are configured in accordance with the persistence.xml specification for the persistence unit, as described in the Java Persistence specification.
The requirements in this section only apply to Jakarta EE products that include support for the Java Persistence API.
5.13.1. Application Component Provider’s Responsibilities
This subsection describes the Application Component Provider’s view of locating the entity manager factory for a persistence unit and defines his or her responsibilities. The first subsection describes annotations for injecting references to an entity manager factory for a persistence unit; the second describes the API for accessing an entity manager factory using a persistence unit reference; and the third describes syntax for declaring persistence unit references in a deployment descriptor.
5.13.1.1. Injection of Persistence Unit References
A field or a method of an application component may be annotated with the PersistenceUnit annotation. The name element specifies the name under which the entity manager factory for the referenced persistence unit may be located in the JNDI naming context. The optional unitName element specifies the name of the persistence unit as declared in the persistence.xml file that defines the persistence unit.
The following code example illustrates how an application component uses annotations to declare persistence unit references.
@PersistenceUnit
EntityManagerFactory emf;
@PersistenceUnit(unitName="InventoryManagement")
EntityManagerFactory inventoryEMF;
5.13.1.2. Programming Interfaces for Persistence Unit References
The Application Component Provider must use persistence unit references to obtain references to entity manager factories as follows.
-
Assign an entry in the application component’s environment to the persistence unit reference. (See subsection Declaration of Persistence Unit References in Deployment Descriptor for information on how persistence unit references are declared in the deployment descriptor.) It is recommended that the Application Component Provider organize all persistence unit references in the java:comp/env/persistence subcontext of the component’s environment.
-
Lookup the entity manager factory for the persistence unit in the application component’s environment using JNDI.
-
Invoke the appropriate method on the entity manager factory to obtain an entity manager instance.
The following code sample illustrates obtaining an entity manager factory.
@PersistenceUnit(name="persistence/InventoryAppDB")
@Stateless
public class InventoryManagerBean implements InventoryManager {
EJBContext ejbContext;
...
public void updateInventory(...) {
...
// obtain the initial JNDI context
Context initCtx = new InitialContext();
// perform JNDI lookup to obtain entity manager factory
EntityManagerFactory = (EntityManagerFactory)
initCtx.lookup(
"java:comp/env/persistence/InventoryAppDB");
// use factory to obtain application-managed entity manager
EntityManager em = emf.createEntityManager();
...
}
}
5.13.1.3. Declaration of Persistence Unit References in Deployment Descriptor
Although a persistence unit reference is an entry in the application component’s environment, the Application Component Provider must not use an env-entry element to declare it.
Instead, if metadata annotations are not used, the Application Component Provider must declare all the persistence unit references in the deployment descriptor using the persistence-unit-ref elements. This allows the Application Assembler or Deployer to discover all the persistence unit references used by an application component. Deployment descriptor entries may also be used to specify injection of a persistence unit reference into an application component.
Each persistence-unit-ref element describes a single entity manager factory reference for the persistence unit. The persistence-unit-ref element consists of the optional description and persistence-unit-name elements, and the mandatory persistence-unit-ref-name element.
The persistence-unit-ref-name element contains the name of the environment entry used in the application component’s code. The name of the environment entry is relative to the java:comp/env context (e.g., the name should be persistence/InventoryAppDB rather than java:comp/env/persistence/InventoryAppDB ). The persistence-unit-name element is the name of the persistence unit, as specified in the persistence.xml file for the persistence unit.
The following example is the declaration of a persistence unit reference used by the InventoryManager enterprise bean illustrated in the previous subsection.
...
<persistence-unit-ref>
<description>
Persistence unit for the inventory management
application.
</description>
<persistence-unit-ref-name>
persistence/InventoryAppDB
</persistence-unit-ref-name>
<persistence-unit-name>
InventoryManagement
</persistence-unit-name>
</persistence-unit-ref>
...
5.13.2. Application Assembler’s Responsibilities
The Application Assembler can use the persistence-unit-name element in the deployment descriptor to disambiguate a reference to a persistence unit.The Application Assembler (or Application Component Provider) may use the following syntax in the persistence-unit-name element of the referencing application component to avoid the need to rename persistence units to have unique names within a Jakarta EE application. The Application Assembler specifies the path name of the root of the persistence.xml file for the referenced persistence unit and appends the name of the persistence unit separated from the path name by # . The path name is relative to the referencing application component jar file. In this manner, multiple persistence units with the same persistence unit name may be uniquely identified when the Application Assembler cannot change persistence unit names.
For example,
...
<persistence-unit-ref>
<description>
Persistence unit for the inventory management
application.
</description>
<persistence-unit-ref-name>
persistence/InventoryAppDB
</persistence-unit-ref-name>
<persistence-unit-name>
../lib/inventory.jar#InventoryManagement
</persistence-unit-name>
</persistence-unit-ref>
...
The Application Assembler uses the persistence-unit-name element to link the persistence unit name InventoryManagement declared in the InventoryManagerBean to the persistence unit named InventoryManagement defined in inventory.jar .
The following rules apply to how a deployment descriptor entry may override a PersistenceUnit annotation:
-
The relevant deployment descriptor entry is located based on the JNDI name used with the annotation (either defaulted or provided explicitly).
-
The persistence-unit-name overrides the unitName element of the annotation. The Application Assembler or Deployer should exercise caution in changing this value, if specified, as doing so is likely to break the application.
-
The injection target, if specified, must name exactly the annotated field or property method.
5.13.3. Deployer’s Responsibility
The Deployer uses deployment tools to bind a persistence unit reference to the actual entity manager factory configured for the persistence unit in the target operational environment.
The Deployer must perform the following tasks for each persistence unit reference declared in the metadata annotations or deployment descriptor:
-
Bind the persistence unit reference to an entity manager factory configured for the persistence unit that exists in the operational environment. The Deployer may use, for example, the JNDI LinkRef mechanism to create a symbolic link to the actual JNDI name of the entity manager factory.
-
If the persistence unit name is specified, the Deployer should bind the persistence unit reference to the entity manager factory for the persistence unit specified as the target.
-
Provide any additional configuration information that the entity manager factory needs for managing the persistence unit, as described in the Java Persistence specification.
5.13.4. Jakarta EE Product Provider’s Responsibility
The Jakarta EE Product Provider is responsible for the following:
-
Provide the deployment tools that allow the Deployer to perform the tasks described in the previous subsection.
-
Provide the implementation of the entity manager factory classes for the persistence units that are configured with the container. The implementation of the entity manager factory classes may be provided by the container directly or by the container in conjunction with a third-party persistence provider, as described in the Java Persistence specification.
5.14. Persistence Context References
This section describes the metadata annotations and deployment descriptor elements that allow the application component code to refer to a container-managed entity manager of a specified persistence context type using a logical name called a persistence context reference . Persistence context references are special entries in the application component’s environment. The Deployer binds the persistence context references to container-managed entity managers for persistence contexts of the specified type and configured in accordance with their persistence unit, as described in the Java Persistence specification.
The requirements in this section only apply to Jakarta EE products that include support for the Java Persistence API.
5.14.1. Application Component Provider’s Responsibilities
This subsection describes the Application Component Provider’s view of locating container-managed entity managers and defines his or her responsibilities. The first subsection describes annotations for injecting references to container-managed entity managers; the second describes the API for accessing references to container-managed entity managers; and the third describes syntax for declaring these references in a deployment descriptor.
5.14.1.1. Injection of Persistence Context References
A field or a method of an application component may be annotated with the PersistenceContext annotation. The name element specifies the name under which a container-managed entity manager for the referenced persistence unit may be located in the JNDI naming context. The optional unitName element specifies the name of the persistence unit as declared in the persistence.xml file that defines the persistence unit. The optional type element specifies whether a transaction-scoped or extended persistence context is to be used. If the type is not specified, a transaction-scoped persistence context will be used. References to container-managed entity managers with extended persistence contexts can only be injected into stateful session beans. The optional synchronization element specifies whether the persistence context is always automatically synchronized with the current transaction or whether it must be explicitly joined to the transaction. If the synchronization element is not specified, the persistence context will be automatically synchronized. The optional properties element specifies configuration properties to be passed to the persistence provider when the entity manager is created.
The following code example illustrates how an application component uses annotations to declare persistence context references.
@PersistenceContext(type=EXTENDED)
EntityManager em;
Programming Interfaces for Persistence Context References
The Application Component Provider may use a persistence context reference to obtain a reference to a container-managed entity manager configured for a persistence unit as follows:
-
Assign an entry in the application component’s environment to the persistence context reference. (See subsection Declaration of Persistence Context References in Deployment Descriptor for information on how persistence context references are declared in the deployment descriptor.) It is recommended that the Application Component Provider organize all persistence context references in the java:comp/env/persistence subcontext of the component’s environment.
-
Lookup the container-managed entity manager for the persistence unit in the application component’s environment using the JNDI API.
The following code sample illustrates obtaining an entity manager for a persistence context.
@PersistenceContext(name="persistence/InventoryAppMgr")
@Stateless
public class InventoryManagerBean implements InventoryManager {
public void updateInventory(...) {
...
// obtain the initial JNDI context
Context initCtx = new InitialContext();
// JNDI lookup to obtain container-managed entity manager
EntityManager = (EntityManager)
initCtx.lookup(
"java:comp/env/persistence/InventoryAppMgr");
...
}
}
5.14.1.2. Declaration of Persistence Context References in Deployment Descriptor
Although a persistence context reference is an entry in the application component’s environment, the Application Component Provider must not use an env-entry element to declare it.
Instead, if metadata annotations are not used, the Application Component Provider must declare all the persistence context references in the deployment descriptor using the persistence-context-ref elements. This allows the Application Assembler or Deployer to discover all the persistence context references used by an application component. Deployment descriptor entries may also be used to specify injection of a persistence context reference into a bean.
Each persistence-context-ref element describes a single container-managed entity manager reference. The persistence-context-ref element consists of the optional description , persistence-unit-name , persistence-context-type , persistence-context-synchronization , and persistence-property elements, and the mandatory persistence-context-ref-name element.
The persistence-context-ref-name element contains the name of the environment entry used in the application component’s code. The name of the environment entry is relative to the java:comp/env context (e.g., the name should be persistence/InventoryAppMgr rather than java:comp/env/persistence/InventoryAppMgr ). The persistence-unit-name element is the name of the persistence unit, as specified in the persistence.xml file for the persistence unit. The persistence-context-type element specifies whether a transaction-scoped or extended persistence context is to be used. Its value is either Transaction or Extended . If the persistence context type is not specified, a transaction-scoped persistence context will be used. The optional persistence-context-synchronization element specifies whether the persistence context is automatically synchronized with the current transaction. Its value is either Synchronized or Unsynchronized . If the persistence context synchronization is not specified, the persistence context will be automatically synchronized. The optional persistence-property elements specify configuration properties that are passed to the persistence provider when the entity manager is created.
The following example is the declaration of a persistence context reference used by the InventoryManager enterprise bean illustrated in the previous subsection.
...
<persistence-context-ref>
<description>
Persistence context for the inventory management
application.
</description>
<persistence-context-ref-name>
persistence/InventoryAppDB
</persistence-context-ref-name>
<persistence-unit-name>
InventoryManagement
</persistence-unit-name>
</persistence-context-ref>
...
5.14.2. Application Assembler’s Responsibilities
The Application Assembler can use the persistence-unit-name element in the deployment descriptor to specify a reference to a persistence unit using the syntax described in Application Assembler’s Responsibilities.” In this manner, multiple persistence units with the same persistence unit name may be uniquely identified when the persistence unit names cannot be changed.
For example,
...
<persistence-context-ref>
<description>
Persistence context for the inventory management
application.
</description>
<persistence-context-ref-name>
persistence/InventoryAppDB
</persistence-context-ref-name>
<persistence-unit-name>
../lib/inventory.jar#InventoryManagement
</persistence-unit-name>
</persistence-context-ref>
...
The Application Assembler uses the persistence-unit-name element to link the persistence unit name InventoryManagement declared in the InventoryManagerBean to the persistence unit named InventoryManagement defined in inventory.jar .
The following rules apply to how a deployment descriptor entry may override a PersistenceContext annotation:
-
The relevant deployment descriptor entry is located based on the JNDI name used with the annotation (either defaulted or provided explicitly).
-
The persistence-unit-name overrides the unitName element of the annotation. The Application Assembler or Deployer should exercise caution in changing this value, if specified, as doing so is likely to break the application.
-
The persistence-context-type , if specified, overrides the type element of the annotation. In general, the Application Assembler or Deployer should never change the value of this element, as doing so is likely to break the application.
-
The persistence-context-synchronization , if specified, overrides the synchronization element of the annotation. In general, the Application Assembler or Deployer should never change the value of this element, as doing so is likely to break the application.
-
Any persistence-property elements are added to those specified by the PersistenceContext annotation. If the name of a specified property is the same as one specified by the PersistenceContext annotation, the value specified in the annotation is overridden.
-
The injection target, if specified, must name exactly the annotated field or property method.
5.14.3. Deployer’s Responsibility
The Deployer uses deployment tools to bind a persistence context reference to the container-managed entity manager for the persistence context of the specified type and configured for the persistence unit in the target operational environment.
The Deployer must perform the following tasks for each persistence context reference declared in the metadata annotations or deployment descriptor:
-
Bind the persistence context reference to a container-managed entity manager for a persistence context of the specified type and configured for the persistence unit as specified in the persistence.xml file for the persistence unit that exists in the operational environment. The Deployer may use, for example, the JNDI LinkRef mechanism to create a symbolic link to the actual JNDI name of the entity manager.
-
If the persistence unit name is specified, the Deployer should bind the persistence context reference to an entity manager for the persistence unit specified as the target.
-
Provide any additional configuration information that the entity manager factory needs for creating such an entity manager and for managing the persistence unit, as described in the Java Persistence specification.
5.14.4. Jakarta EE Product Provider’s Responsibility
The Jakarta EE Product Provider is responsible for the following:
-
Provide the deployment tools that allow the Deployer to perform the tasks described in the previous subsection.
-
Provide the implementation of the entity manager classes for the persistence units that are configured with the container. This implementation may be provided by the container directory or by the container in conjunction with a third-party persistence provider, as described in the Java Persistence specification.
5.15. Application Name and Module Name References
A component may access the name of the current application using the pre-defined JNDI name java:app/AppName . A component may access the name of the current module using the pre-defined JNDI name java:module/ModuleName . Both of these names are represented by String objects.
5.15.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for requesting injection of the application name or module name using a Resource annotation on a String method or field, or using the defined name to look up the application name or module name.
5.16. Application Client Container Property
An application may determine whether it is executing in a Jakarta EE application client container by using the pre-defined JNDI name java:comp/InAppClientContainer . This property is represented by a Boolean object. If the application is running in a Jakarta EE application client container, the value of this property is true. If the application is running in a Jakarta EE web or enterprise bean container, the value of this property is false.
5.16.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for requesting injection of the application client container property using a Resource annotation on a Boolean or boolean method or field, or using the defined name to look up the application client container property.
5.17. Validator and Validator Factory References
This section describes the metadata annotations and deployment descriptor entries that allow an application to obtain instances of the Bean Validation Validator and ValidatorFactory types.
Applications that need to use those interfaces can find appropriate objects by looking up the name java:comp/Validator for Validator and java:comp/ValidatorFactory for ValidatorFactory , or by requesting the injection of an object of the appropriate type via the Resource annotation. The authenticationType and shareable elements of the Resource annotation must not be specified.
@Resource ValidatorFactory validatorFactory;
@Resource Validator validator;
For Validator objects, the default validation context is used. This means that all such Validators will be equivalent to those obtained by first acquiring a ValidatorFactory and then invoking the getValidator method on it with no arguments.
In other words, the following two code snippets are equivalent:
// obtaining a Validator directly
Context initCtx = new InitialContext();
Validator validator = (Validator)initCtx.lookup(
"java:comp/Validator");
// obtaining a Validator from a ValidatorFactory
Context initCtx = new InitialContext();
Validator validator =
((ValidatorFactory) initCtx.lookup(
"java:comp/ValidatorFactory"))
.getValidator();
A Validator or ValidatorFactory object reference may also be declared in a deployment descriptor in the same way as a resource environment reference.
In order to customize the returned ValidatorFactory , a Jakarta Enterprise Beans, web or application client module may specify a Bean Validation XML deployment descriptor, as described in the Bean Validation specification.
A validation deployment descriptor only affects ValidatorFactory instances in that module.
There is no per-application validation deployment descriptor.
5.17.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for requesting injection of a Validator or of a ValidatorFactory using a Resource annotation, or using the defined names to look up a Validator or ValidatorFactory instance.
The Application Component Provider may customize the ValidatorFactory and (indirectly) Validator instances by including a Bean Validation deployment descriptor inside a specific module of the application.
5.17.2. Jakarta EE Product Provider’s Responsibilities
The Jakarta EE Product Provider must make a default ValidatorFactory available at java:comp/ValidatorFactory . The default ValidatorFactory available at java:comp/ValidatorFactory must support use of CDI if CDI is enabled for the module. In particular, all of the classes specified by the javax.validation.BootstrapConfiguration interface must be created as non-contextual objects using CDI, as described in Support for Dependency Injection”. These objects must be used to configure the default ValidatorFactory available at java:comp/ValidatorFactory in accordance with the bootstrapping APIs described by the Bean Validation specification.
The default ValidatorFactory is a single instance per module; each lookup of java:comp/ValidatorFactory returns the same instance.
The default Validator is created by the default ValidatoryFactory using the getValidator method. Each lookup of java:comp/Validator returns a new Validator instance.
5.18. Resource Definition and Configuration
In addition to referencing resources as defined in this chapter, an application may specify the definition and configuration of resources that it requires in its operational environment.
Each application has a set of “physical” resources and services that it depends on (database storage, queueing, mail, etc.) and which need to be made available to it when it is deployed. Such resources may be scoped to the application instance or may be shareable. An application may define a dependency upon such resources in its environment by means of resource definition metadata.
The specification of resource definition metadata provides information that can be used at the application’s deployment to provision and configure the required resource. Further, resource definitions allow an application to be deployed into a Jakarta EE environment with more minimal administrative configuration.
Resources may be defined in any of the JNDI namespaces described in Application Component Environment Namespaces”. For example, a resource may be defined:
in the java:comp namespace, for use by a single component;
-
in the java:module namespace, for use by all components in a module;
-
in the java:app namespace, for use by all components in an application;
-
in the java:global namespace, for use by all applications.
The following annotations (and corresponding XML deployment descriptor elements) define resources: DataSourceDefinition , JMSConnectionFactoryDefinition , JMSDestinationDefinition , MailSessionDefinition , ConnectionFactoryDefinition , and AdministeredObjectDefinition .
Once defined, a resource may be referenced by a component using the lookup element of the Resource annotation or the lookup-name element of the resource-ref deployment descriptor element in order to bind the logical reference to the resource as referenced in the application code to the resource defined in the environment. __
The specificity of the resource definition elements as provided by the Application Component Provider may vary according to the needs of the application. For example:
-
An application may require an instance of a resource, but its needs may be general in that while it requires a resource with certain properties, it does not require a particular instance of the resource. It may expect the resource to be provisioned and configured for it by the Deployer or System Administrator.
-
An application may require a particular instance of a resource (with specific configuration properties) that already exists. For example, the resource may previously have been created and configured by the Deployer or System Administrator.
The values specified for required annotation elements (and corresponding XML deployment descriptor elements) must be observed when the application is deployed. Changing a value that has been specified for some optional elements (e.g., transactional ) may cause the application to work incorrectly. Changing a value that has been specified for an optional element related to quality of service (e.g., pool size, idle time, etc.) may affect the performance of the application.
The following default values used in the DataSourceDefinition , JMSConnectionFactoryDefinition , JMSDestinationDefinition , MailSessionDefinition , and ConnectionFactoryDefinition annotations indicate that an element value is optional and has not been set:
-
integer-valued elements: -1
-
string-valued elements: “”
-
array-valued elements: {}
5.18.1. Guidelines
The following guidelines should be observed with regard to the specification of values for resource definition elements.
-
In general, the Application Component Provider or Assembler should specify values for elements which, if changed, would cause the application to break—for example, JNDI name, isolation level. If multiple resource definitions are specified for a given resource, they must be consistent.
-
The Jakarta EE Product Provider may choose suitable server-specific default values for optional elements for which values have not been specified.
5.18.2. Requirements Common to All Resource Definition Types
The following requirements apply to the resource definitions described in Sections DataSource Resource Definition through Connector Administered Object Definition.
When an Application Component Provider or Application Assembler specifies connectivity information to a “physical” resource through a resource definition annotation or deployment descriptor element, it is assumed that the physical resource exists. The automatic provisioning of resources may be supported by an implementation of this specification, but support for this functionality is not required. If automatic provisioning of resources is not supported, it is the Deployer’s responsibility (possibly in conjunction with the System Administrator) to insure that the physical resource is provisioned for use by the application.
5.18.2.1. JNDI Name
The Deployer and Jakarta EE Product Provider must not alter the specified JNDI name. The requested resource must be made available in JNDI under the specified name.
5.18.2.2. Resource Address
If the Application Component Provider or Application Assembler has specified an address for a resource (server name, port, etc.), a resource at the specified location should already exist. If it does not, and if the automatic provisioning of resources is not supported, it is the Deployer’s responsibility (possibly in conjunction with the System Administrator) to insure that the resource is provisioned for use by the application.[13]
If the resource has not been otherwise provisioned and if automatic provisioning of resources is supported, the Jakarta EE Product Provider is responsible for provisioning the resource. If the requested resource cannot be made available or created, the application must fail to deploy.
5.18.2.3. Quality of Service Elements
Quality of service elements may be altered by the Deployer. The Jakarta EE Product Provider is permitted to impose restrictions upon quality of service elements in accordance with its implementation limits and quality of service guarantees. If quality of service values that have been specified do not meet these restrictions, the Product Provider must not reject the deployment (but must instead use appropriate values).
5.18.2.4. Properties
All resource definition annotations and XML elements support the use of property elements (elements named “ properties ” or “ property ”). A Jakarta EE Product Provider is permitted to reject a deployment if a property that it recognizes has a value that it does not support. A Jakarta EE Product Provider must not reject a deployment on the basis of a property that it does not recognize.
5.18.3. DataSource Resource Definition
An application may define a DataSource resource. A DataSource resource is used to access a database using a JDBC driver.
The DataSource resource may be defined in any of the JNDI namespaces described in Application Component Environment Namespaces”.
A DataSource resource may be defined in a web module, enterprise bean module, application client module, or application deployment descriptor using the data-source element.
For example:
<data-source>
<description>Sample DataSource definition</description>
<name>java:app/MyDataSource</name>
<class-name>com.example.MyDataSource</class-name>
<server-name>myserver.com</server-name>
<port-number>6689</port-number>
<database-name>myDatabase</database-name>
<user>lance</user>
<password>secret</password>
<property>
<name>Property1</name>
<value>10</value>
</property>
<property>
<name>Property2</name>
<value>20</value>
</property>
<login-timeout>0</login-timeout>
<transactional>false</transactional>
<isolation-level>TRANSACTION_READ_COMMITTED</isolation-level>
<initial-pool-size>0</initial-pool-size>
<max-pool-size>30</max-pool-size>
<min-pool-size>20</min-pool-size>
<max-idle-time>0</max-idle-time>
<max-statements>50</max-statements>
</data-source>
A DataSource resource may also be defined using the DataSourceDefinition annotation on a container-managed class, such as a servlet or enterprise bean class.
For example:
@DataSourceDefinition(
name="java:app/MyDataSource",
className="com.example.MyDataSource",
portNumber=6689,
serverName="myserver.com",
user="lance",
password="secret")
(Of course, we do not recommend including passwords to production systems in the code, but it’s often useful while testing. Passwords, or other parts of the DataSource definition, can be overridden by a deployment descriptor when the application is deployed.)
Once defined, a DataSource resource may be referenced by a component using the resource-ref deployment descriptor element or the Resource annotation. For example, the above DataSource could be referenced as follows:
@Stateless
public class MySessionBean {
@Resource(lookup = "java:app/MyDataSource")
DataSource myDB;
...
}
The following DataSourceDefinition annotation elements (and corresponding XML deployment descriptor elements) are considered to specify an address for a DataSource resource: serverName , portNumber , databaseName , url .
The following DataSourceDefinition annotation elements (and corresponding XML deployment descriptor elements) are considered to be quality of service elements: loginTimeout , initialPoolSize , maxPoolSize , minPoolSize , maxIdleTime , maxStatements .
5.18.3.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for the definition of a DataSource resource using a DataSourceDefinition annotation or the data-source deployment descriptor element.
If the database has been previously provisioned for the application (e.g., by administrative action), it is the responsibility of the Application Component Provider to specify the class name of the data source implementation class and the server and port at which the database is to be accessed.
A URL should not be specified in conjunction with address elements such as server name and port. If it is, the precedence order is undefined and implementation specific.
5.18.3.2. Deployer’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”. The following additional requirements apply:
If specified, user name and password should be used as specified.
-
The transactional specification and isolation level must be used as specified.
5.18.3.3. Jakarta EE Product Provider’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”. The following additional requirements apply:
-
If a class name is specified, a resource with the specified implementation class (or a subclass) must be provided. If the class name is specified as XADataSource , an XA datasource must be provided.
-
If an isolation level is specified, the Product Provider must satisfy the request or provide a higher level of isolation. If the request cannot be satisfied, the Product Provider must reject the deployment.
5.18.4. Jakarta Messaging Connection Factory Resource Definition
An application may define a Jakarta Messaging ConnectionFactory resource.
The Jakarta Messaging ConnectionFactory resource may be defined in any of the JNDI namespaces described in Application Component Environment Namespaces”.
A Jakarta Messaging ConnectionFactory resource may be defined in a web module, enterprise bean module, application client module, or application deployment descriptor using the jms-connection-factory element.
For example:
<jms-connection-factory>
<description>
Sample Jakarta Messaging ConnectionFactory definition
</description>
<name>java:app/MyJMSCF</name>
<interface-name>
javax.jms.QueueConnectionFactory
</interface-name>
<resource-adapter>myJMSRA</resource-adapter>
<user>scott</user>
<password>secret</password>
<client-id>MyId</client-id>
<property>
<name>Property1</name>
<value>10</value>
</property>
<property>
<name>Property2</name>
<value>20</value>
</property>
<transactional>false</transactional>
<max-pool-size>30</max-pool-size>
<min-pool-size>20</min-pool-size>
</jms-connection-factory>
A Jakarta Messaging ConnectionFactory resource may also be defined using the JMSConnectionFactoryDefinition annotation on a container-managed class, such as a servlet or enterprise bean class.
For example:
@JMSConnectionFactoryDefinition(
name="java:app/MyJMSCF",
interfaceName="javax.jms.QueueConnectionFactory",
resourceAdapter="myJMSRA")
(As with the DataSource definition, we do not recommend including passwords to production systems in the code, but it’s often useful while testing. Passwords, or other parts of the JMSConnectionFactoryDefinition annotation, can be overridden by a deployment descriptor when the application is deployed.)
Once defined, a Jakarta Messaging ConnectionFactory resource may be referenced by a component using the resource-ref deployment descriptor element or the Resource annotation. For example, the above Jakarta Messaging ConnectionFactory could be referenced as follows:
@Stateless_
public class MySessionBean {
@Resource(lookup = "java:app/MyJMSCF")
ConnectionFactory myCF;
...
}
The following JMSConnectionFactoryDefinition annotation elements (and corresponding XML deployment descriptor elements) are considered to specify an address for a Jakarta Messaging ConnectionFactory resource: resourceAdapter .
The following JMSConnectionFactoryDefinition annotation elements (and corresponding XML deployment descriptor elements) are considered to be quality of service elements: maxPoolSize , minPoolSize .
5.18.4.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for the definition of a Jakarta Messaging ConnectionFactory using a JMSConnectionFactoryDefinition annotation or the jms-connection-factory deployment descriptor element.
5.18.4.2. Deployer’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”. The following additional requirements apply:
A resource of the specified interface type (or of the default interface type, if not specified) must be provided.
-
If specified, user name and password should be used as specified.
-
The transactional specification must be used as specified.
-
If specified, the client id should be used as specified.
5.18.4.3. Jakarta EE Product Provider’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”.
5.18.5. Jakarta Messaging Destination Definition
An application may define a Jakarta Messaging Destination resource. A Jakarta Messaging Destination resource is a Jakarta Messaging Queue or Topic.
The Jakarta Messaging Destination resource may be defined in any of the JNDI namespaces described in Application Component Environment Namespaces”.
A Jakarta Messaging Destination resource may be defined in a web module, enterprise bean module, application client module, or application deployment descriptor using the jms-destination element.
For example:
<jms-destination>
<description>Sample Jakarta Messaging Destination definition</description>
<name>java:app/MyJMSDestination</name>
<interface-name>javax.jms.Queue</interface-name>
<resource-adapter>myJMSRA</resource-adapter>
<destination-name>myQueue1</destination-name>
<property>
<name>Property1</name>
<value>10</value>
</property>
<property>
<name>Property2</name>
<value>20</value>
</property>
</jms-destination>
A Jakarta Messaging Destination resource may also be defined using the JMSDestinationDefinition annotation on a container-managed class, such as a servlet or enterprise bean class.
For example:
@JMSDestinationDefinition(
name="java:app/MyJMSQueue",
interfaceName="javax.jms.Queue",
destinationName="myQueue1")
The JMSDestinationDefinition annotation can be overridden by a deployment descriptor when the application is deployed.
Once defined, a Jakarta Messaging Destination resource may be referenced by a component using either the resource-env-ref or message-destination-ref deployment descriptor element or the Resource annotation. For example, the above Destination could be referenced as follows:
@Stateless
public class MySessionBean {
@Resource(lookup = "java:app/MyJMSQueue")
Queue myQueue;
...
}
The following JMSDestinationDefinition annotation elements (and corresponding XML deployment descriptor elements) are considered to specify an address for a Jakarta Messaging Destination resource: resourceAdapter , destinationName .
5.18.5.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for the definition of a Jakarta Messaging Destination using a JMSDestinationDefinition annotation or the jms-destination deployment descriptor element.
5.18.5.2. Deployer’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”. The following additional requirements apply:
A resource of the specified interface type must be provided.
5.18.5.3. Jakarta EE Product Provider’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”.
5.18.6. Mail Session Definition
An application may define a Mail Session resource.
The Mail Session resource may be defined in any of the JNDI namespaces described in Application Component Environment Namespaces”.
A Mail Session resource may be defined in a web module, enterprise bean module, application client module, or application deployment descriptor using the mail-session element.
For example:
<mail-session>
<description>Sample Mail Session definition</description>
<name>java:app/mail/MySession</name>
<store-protocol>imap</store-protocol>
<transport-protocol>smtp</transport-protocol>
<host>somewhere.myco.com</host>
<user>linda</user>
<password>secret</password>
<from>some.body@myco.com</from>
<property>
<name>mail.smtp.starttls.enable</name>
<value>true</value>
</property>
<property>
<name>mail.imap.connectiontimeout</name>
<value>500</value>
</property>
</mail-session>
A Mail Session resource may also be defined using the MailSessionDefinition annotation on a container-managed class, such as a servlet or enterprise bean class.
For example:
@MailSessionDefinition(_
name="java:app/mail/MySession",
host="somewhere.myco.com",
from="some.body@myco.com")
The MailSessionDefinition annotation can be overridden by a deployment descriptor when the application is deployed.
Once defined, a Mail Session resource may be referenced by a component using the resource-ref deployment descriptor element or the Resource annotation. For example, the above Destination could be referenced as follows:
@Stateless
public class MySessionBean {
@Resource(lookup = "java:app/mail/MySession")
Session myMailSession;
...
}
The following MailSessionDefinition annotation elements (and corresponding XML deployment descriptor elements) are considered to specify an address for a Mail Session resource: host .
5.18.6.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for the definition of a Mail Session using a MailSessionDefinition annotation or the mail-session deployment descriptor element.
If a mail server resource has been previously provisioned for the application (e.g., by administrative action), it is the responsibility of the Application Component Provider to specify the mail server host name.
5.18.6.2. Deployer’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”. The following additional requirements apply:
-
If store protocol, store protocol class, transport protocol, or transport protocol class has been specified, a resource with the specified property or properties should be provided.
-
If specified, the user name and password should be used as specified.
-
If specified, the from address should be used as specified.
5.18.6.3. Jakarta EE Product Provider’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”.
5.18.7. Connector Connection Factory Definition
An application may define Connector connection factory resources.
The resource may be defined in any of the JNDI namespaces described in Application Component Environment Namespaces”.
A Connector connection factory resource may be defined in a web module, enterprise bean module, or application deployment descriptor using the connection-factory element.
For example:
<connection-factory>
<description>Sample Connector resource definition</description>
<name>java:app/myConnectionFactory</name>
<interface-name>
com.eis.ConnectionFactory
</interface-name>
<resource-adapter>MyEISRA</resource-adapter>
<max-pool-size>20</max-pool-size>
<min-pool-size>10</min-pool-size>
<transaction-support>XATransaction</transaction-support>
<property>
<name>Property1</name>
<value>prop1val</value>
</property>
<property>
<name>Property2</name>
<value>prop2val</value>
</property>
</connection-factory>
A Connector connection factory resource may also be defined using the ConnectionFactoryDefinition annotation on a container-managed class, such as a servlet or enterprise bean class.
For example:
@ConnectionFactoryDefinition(
name="java:app/myConnectionFactory",
interfaceName="com.eis.ConnectionFactory",
resourceAdapter="MyESRA")
The ConnectionFactoryDefinition annotation can be overridden by a deployment descriptor when the application is deployed.
Once defined, a Connector connection factory resource may be referenced by a component using the resource-ref deployment descriptor element or the Resource annotation. For example, the above Connector connection factory resource could be referenced as follows:
@Stateless
public class MySessionBean {
@Resource(lookup = "java:app/myConnectionFactory")
ConnectionFactory myCF;
...
}
5.18.7.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for the definition of a Connector connection factory resource using a ConnectionFactoryDefinition annotation or the connection-factory deployment descriptor element.
5.18.7.2. Deployer’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”. The following additional requirements apply:
-
A resource of the specified type must be provided.
5.18.7.3. Jakarta EE Product Provider’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”.
5.18.8. Connector Administered Object Definition
An application may define a Connector administered object resource. The administered object resource may be defined in any of the JNDI namespaces described in Application Component Environment Namespaces”.
An administered object resource may be defined in a web module, enterprise bean module, or application deployment descriptor using the administered-object element. Properties that are specified are used in the configuration of the administered object, as described in the Connector specification.
For example:
<administered-object>
<description>Sample Admin Object definition</description>
<name>java:app/MyAdminObject</name>
<class-name>com.extraServices.AdminObject</class-name>
<resource-adapter>myESRA</resource-adapter>
<property>
<name>Property1</name>
<value>10</value>
</property>
<property>
<name>Property2</name>
<value>20</value>
</property>
</administered-object>
An administered object resource may also be defined using the AdministeredObjectDefinition annotation on a container-managed class, such as a servlet or enterprise bean class.
For example:
@AdministeredObjectDefinition(
name="java:app/myAdminObject",
className="com.extraServices.AdminObject",
resourceAdapter="myESRA")
The AdministeredObjectDefinition annotation can be overridden by a deployment descriptor when the application is deployed.
Once defined, an administered object resource may be referenced by a component using the resource-env-ref deployment descriptor element or the Resource annotation. For example, the above administered object resource could be referenced as follows:
@Stateless public class MySessionBean {
@Resource(lookup="java:app/myAdminObject")
AdminObject myAdminObject;
...
}
5.18.8.1. Application Component Provider’s Responsibilities
The Application Component Provider is responsible for the definition of an administered object resource using an AdministeredObjectDefinition annotation or the administered-object deployment descriptor element.
5.18.8.2. Deployer’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types”. The following additional requirements apply:
If a class name is specified, an administered object resource of the specified class (or a subclass) must be provided.
5.18.8.3. Jakarta EE Product Provider’s Responsibilities
Requirements common to all resource definition types are described in Requirements Common to All Resource Definition Types.”
5.19. Default Data Source
The Jakarta EE Platform requires that a Jakarta EE Product Provider provide a database in the operational environment (see Database”). The Jakarta EE Product Provider must also provide a preconfigured, default data source for use by the application in accessing this database.
The Jakarta EE Product Provider must make the default data source accessible to the application under the JNDI name java:comp/DefaultDataSource .
The Application Component Provider or Application Assembler may explicitly bind a DataSource resource reference to the default data source using the lookup element of the Resource annotation or the lookup-name element of the resource-ref deployment descriptor element. For example,
@Resource(lookup="java:comp/DefaultDataSource")
DataSource myDS;
In the absence of such a binding, or an equivalent product-specific binding, the mapping of the reference will default to the product’s default data source.
For example, the following will map to a preconfigured data source for the product’s default database:
@Resource
DataSource myDS;
5.19.1. Jakarta EE Product Provider’s Responsibilities
The Jakarta EE Product Provider must provide a database in the operational environment. The Jakarta EE Product Provider must also provide a preconfigured, default data source for use by the application in accessing this database under the JNDI name java:comp/DefaultDataSource .
If a DataSource resource reference is not mapped to a specific data source by the Application Component Provider, Application Assembler, or Deployer, it must be mapped by the Jakarta EE Product Provider to a preconfigured data source for the Jakarta EE Product Provider’s default database.
5.20. Default Jakarta Messaging Connection Factory
The Jakarta EE Platform requires that a Jakarta EE Product Provider provide a Jakarta Messaging provider in the operational environment (see Jakarta™ Message Service (Jakarta Messaging)”) . The Jakarta EE Product Provider must also provide a preconfigured, Jakarta Messaging ConnectionFactory for use by the application in accessing this Jakarta Messaging provider.
The Jakarta EE Product Provider must make the default Jakarta Messaging connection factory accessible to the application under the JNDI name java:comp/DefaultJMSConnectionFactory .
The Application Component Provider or Application Assembler may explicitly bind a Jakarta Messaging ConnectionFactory resource reference to the default connection factory using the lookup element of the Resource annotation or the lookup-name element of the resource-ref deployment descriptor element. For example,
@Resource(name="myJMSCF",
lookup="java:comp/DefaultJMSConnectionFactory")
ConnectionFactory myJMScf;
In the absence of such a binding, or an equivalent product-specific binding, the mapping of the reference will default to a Jakarta Messaging connection factory for the product’s Jakarta Messaging provider.
For example, the following will map to a preconfigured connection factory for the product’s default Jakarta Messaging provider:
@Resource(name="myJMSCF")
ConnectionFactory myJMScf;
5.20.1. Jakarta EE Product Provider’s Responsibilities
The Jakarta EE Product Provider must provide a Jakarta Messaging provider in the operational environment. The Jakarta EE Product Provider must also provide a preconfigured, default Jakarta Messaging connection factory for use by the application in accessing this provider under the JNDI name java:comp/DefaultJMSConnectionFactory .
If a Jakarta Messaging ConnectionFactory resource reference is not mapped to a specific Jakarta Messaging connection factory by the Application Component Provider, Application Assembler, or Deployer, it must be mapped by the Jakarta EE Product Provider to a preconfigured Jakarta Messaging connection factory for the Jakarta EE Product Provider’s default Jakarta Messaging provider.
5.21. Default Jakarta Concurrency Objects
The Jakarta EE Platform requires that a Jakarta EE Product Provider provide a preconfigured default managed executor service, a preconfigured default managed scheduled executor service, a preconfigured default managed thread factory, and a preconfigured default context service for use by the application.
The Jakarta EE Product Provider must make the default Jakarta Concurrency objects accessible to the application under the following JNDI names:
-
java:comp/ DefaultManagedExecutorService for the preconfigured managed executor service
-
java:comp/DefaultManagedScheduledExecutorService for the preconfigured managed scheduled executor service
-
java:comp/DefaultManagedThreadFactory for the preconfigured managed thread factory
-
java:comp/DefaultContextService for the preconfigured context service
The Application Component Provider or Application Assembler may explicitly bind a resource reference to a default Jakarta Concurrency object using the lookup element of the Resource annotation or the lookup-name element of the resource-ref deployment descriptor element. For example,
@Resource(name="myManagedExecutorService",
lookup="java:comp/DefaultManagedExecutorService")
ManagedExecutorService myManagedExecutorService;
In the absence of such a binding, or an equivalent product-specific binding, the mapping of the reference will default to the product’s default managed executor service.
For example, the following will map to a preconfigured default managed executor service for the product:
@Resource(name="myManagedExecutorService")
ManagedExecutorService myManagedExecutorService;
5.21.1. Jakarta EE Product Provider’s Responsibilities
The Jakarta EE Product Provider must provide the following:
a preconfigured, default managed executor service for use by the application in accessing this service under the JNDI name java:comp/DefaultManagedExecutorService ;
-
a preconfigured, default managed scheduled executor service for use by the application in accessing this service under the JNDI name java:comp/DefaultManagedScheduledExecutorService ;
-
a preconfigured, default managed thread factory for use by the application in accessing this factory under the JNDI name java:comp/DefaultManagedThreadFactory ;
-
a preconfigured, default context service for use by the application in accessing this service under the JNDI name java:comp/DefaultContextService .
If a Jakarta Concurrency object resource environment reference is not mapped to a specific configured object by the Application Component Provider, Application Assembler, or Deployer, it must be mapped by the Jakarta EE Product Provider to a preconfigured Jakarta Concurrency object for the Jakarta EE Product Provider.
5.22. Managed Bean References
This section describes the metadata annotations and deployment descriptor entries that allow an application to obtain instances of a Managed Bean.
An instance of a named Managed Bean can be obtained by looking up its name in JNDI using the same naming scheme used for Jakarta Enterprise Beans components:
java:app/<module-name>/<bean-name> java:module/<bean-name>
The latter will only work within the module the Managed Bean is declared in.
Each such lookup must return a new instance.
Alternatively, the Resource annotation can be used to request the injection of a Managed Bean given either its type or its name. If a name is specified using the lookup element then the type of the resource can be any of the types that the Managed Bean class implements, including any of its interfaces. If no name is specified, the type must be the Managed Bean class itself. (Note that the name element of the Resource annotation serves an entirely different purpose than the lookup element, consistently with other uses of Resource in this specification.) The authenticationType and shareable elements of the Resource annotation must not be specified.
For example, given a ShoppingCartBean bean named “cart” defined in the same module as the client code and implementing the ShoppingCart interface, a client may use any of the following methods to obtain an instance of the bean class:
@Resource ShoppingCartBean cart;
@Resource(lookup="java:module/cart") ShoppingCart cart;
ShoppingCart cart = (ShoppingCart) context.lookup("java:module/cart");
References to managed beans can be declared in the deployment descriptor using the resource-ref element. The res-type element must contain a type that the managed bean implements. The lookup-name must be present and refer to a managed bean by name. The res-sharing-scope and res-auth elements may be omitted; if present, they must have the values Shareable and Container respectively, so as to match the default values of the corresponding elements of the Resource annotation.
The following example shows how to declare references to the shopping cart bean of the previous example, this time using descriptors. (To make the example somewhat more realistic, one should add an injection-target child element to resource-ref .)
<resource-ref>
<res-ref-name>bean/cart</ref-ref-name>
<ref-type>com.acme.ShoppingCart</ref-type>
<lookup-name>java:module/cart</lookup-name>
</resource-ref>
5.23. Bean Manager References
This section describes the metadata annotations and deployment descriptor entries that allow an application to obtain instances of the CDI BeanManager type.
Typically, only portable extensions using the CDI SPI need to access a BeanManager . Application code may occasionally require access to that interface; in that case, the application should either look up a BeanManager instance in JNDI under the name java:comp/BeanManager , or request the injection of an object of type javax.enterprise.inject.spi.BeanManager via the Resource annotation. If the latter, the authenticationType and shareable elements of the Resource annotation must not be specified.
@Resource BeanManager manager;
Per the CDI specification, a bean can also request the injection of a BeanManager using the Inject annotation.
@Inject BeanManager manager;
A BeanManager object reference may also be declared in a deployment descriptor in the same way as a resource environment reference.
5.24. Support for Dependency Injection
In Jakarta EE, support for dependency injection annotations as specified in the Dependency Injection for Java specification is mediated by CDI. Containers must support injection points annotated with the javax.inject.Inject annotation only to the extent dictated by CDI.
Per the CDI specification, dependency injection is supported on managed beans. There are currently three ways for a class to become a managed bean:
-
Being a Jakarta Enterprise Beans session bean component.
-
Being annotated with the ManagedBean annotation.
-
Satisfying the conditions described in the CDI specification.
Classes that satisfy at least one of these conditions will be eligible for full dependency injection support as described in the CDI specification.
Component classes listed in Component classes supporting injection that satisfy the third condition above, but neither the first nor the second condition, can also be used as CDI managed beans if they are annotated with a CDI bean-defining annotation or contained in a bean archive for which CDI is enabled. However, if they are used as CDI managed beans (e.g., injected into other managed classes), the instances that are managed by CDI may not be the instances that are managed by the Jakarta EE container.
Therefore, to make injection support more uniform across all Jakarta EE component types, Jakarta EE containers are required to support field, method, and constructor injection using the javax.inject.Inject annotation into all component classes listed in Component classes supporting injection as having the “Standard” level of injection support, as well as the use of interceptors for these classes. Such injection must be performed in the same logical phase as resource injection of fields and methods annotated with the Resource annotation. In particular, dependency injection must precede the invocation of any methods annotated with the PostConstruct annotation. In supporting such injection points, the container must behave as if it carried out the following steps, involving the use of the CDI SPI. Note that using these steps causes the container to create a non-contextual instance, which is not managed by CDI but rather by the Jakarta EE container.
-
Obtain a BeanManager instance.
-
Create an AnnotatedType instance for the component into which injection is to occur.
-
Create an InjectionTarget instance for the annotated type.
-
Create a CreationalContext , passing in null to the BeanManager createCreationalContext method.
-
Instantiate the component by calling the InjectionTarget produce method.
-
Inject the component instance by calling the InjectionTarget inject method on the instance.
-
Invoke the PostConstruct callback, if any, by calling the InjectionTarget postConstruct method on the instance.
When such a non-contextual instance is to be destroyed, the container should behave as if it carried out the following steps.
-
Invoke the PreDestroy callback, if any, by calling the InjectionTarget preDestroy method on the instance.
-
Invoke the InjectionTarget dispose method on the instance.
-
Invoke the CreationalContext release method to destroy any dependent objects of the instance.
Containers may optimize the steps above, e.g., by avoiding calls to the actual CDI SPI and relying on container-specific interfaces instead, as long as the outcome is the same.
6. Application Programming Interface
This chapter describes API requirements for the Jakarta™ Platform, Enterprise Edition (Jakarta EE). Jakarta EE requires the provision of a number of APIs for use by Jakarta EE applications, starting with the core Java APIs and including many additional Java technologies.
6.1. Required APIs
Jakarta EE application components execute in runtime environments provided by the containers that are a part of the Jakarta EE platform. The full Jakarta EE platform supports four types of containers corresponding to Jakarta EE application component types: application client containers; applet containers; web containers for servlets, Jakarta Server Pages, Jakarta Server Faces applications, Jakarta RESTful Web Services applications; and enterprise bean containers. A Jakarta EE profile may support only a subset of these component types, as defined by the individual Jakarta EE profile specification.
The per-technology requirements in this chapter apply to any Jakarta EE product that includes the technology. Note that even though a Jakarta EE profile might not require support for a particular technology, a Jakarta EE product based on that Jakarta EE profile might nonetheless include support for the technology. In such a case, the requirements for that technology described in this chapter would apply.
6.1.1. Java Compatible APIs
The containers provide all application components with at least the Java Platform, Standard Edition, v8 (Java SE) APIs. Containers may provide newer versions of the Java SE platform, provided they meet all the Jakarta EE platform requirements. The Java SE platform includes the following enterprise technologies:
-
Java IDL
-
JDBC
-
RMI-IIOP
-
JNDI
-
JAXP
-
StAX
-
JAAS
-
JMX
-
JAX-WS
-
JAXB
-
JAF
-
SAAJ
-
Common Annotations
In particular, the applet execution environment must be Java SE 8 compatible. Since typical browsers don’t yet provide such support, Jakarta EE products may make use of the Java Plugin to provide the required applet execution environment. Use of the Java Plugin is not required, but is one method of meeting the requirement to provide a Java SE 8 compatible applet execution environment. This specification adds no requirements to the applet container beyond those specified by Java SE.
Some of the enterprise technologies that are included in Java SE 8 are also available independently of the Java SE platform, and this specification requires newer versions of some of these technologies, as described in the following section.
The specifications for the Java SE APIs are available at http://docs.oracle.com/javase/8/docs/ .
6.1.2. Required Java Technologies
The full Jakarta EE platform also provides a number of Java technologies in each of the containers defined by this specification. Jakarta EE Technologies indicates the technologies with their required versions, which containers include the technologies, and whether the technology is required (REQ), proposed optional (POPT), or optional (OPT). Each Jakarta EE profile specification will include a similar table describing which technologies are required for the profile. Note that some technologies are marked Optional, as described in the next section.
Java Technology | App Client | Web | Enterprise Beans | Status |
---|---|---|---|---|
Enterprise Beans 3.2 |
Y [14] |
Y |
Y |
|
Servlet 4.0 |
N |
Y |
N |
REQ |
Server Pages 2.3 |
N |
Y |
N |
REQ |
Expression Language 3.0 |
N |
Y |
N |
REQ |
Messaging 2.0 |
Y |
Y |
Y |
REQ |
Transactions 1.3 |
N |
Y |
Y |
REQ |
Mail 1.6 |
Y |
Y |
Y |
REQ |
Connector 1.7 |
N |
Y |
Y |
REQ |
Enterprise Web Services 1.4 |
Y |
Y |
Y |
REQ |
XML RPC 1.1 |
Y |
Y |
Y |
OPT |
RESTful Web Services 2.1 |
N |
Y |
N |
REQ |
WebSocket 1.1 |
N |
Y |
N |
REQ |
JSON Processing 1.1 |
Y |
Y |
Y |
REQ |
JSON Binding 1.0 |
Y |
Y |
Y |
REQ |
Concurrency 1.1 |
N |
Y |
Y |
REQ |
Batch 1.0 |
N |
Y |
Y |
REQ |
XML Registries 1.0 |
Y |
Y |
Y |
OPT |
Management 1.1 |
Y |
Y |
Y |
REQ |
Deployment 1.7 [17] |
N |
N |
N |
OPT |
Authorization 1.5 |
N |
Y |
Y |
REQ |
Authentication 1.1 |
N |
Y |
Y |
REQ |
Security API 1.0 |
N |
Y |
Y |
REQ |
Server Pages Debugging 1.0 |
N |
Y |
N |
REQ |
Standard Tag Library 1.2 |
N |
Y |
N |
REQ |
Server Faces 2.3 |
N |
Y |
N |
REQ |
Common Annotations 1.3 |
Y |
Y |
Y |
REQ |
Persistence 2.2 |
Y |
Y |
Y |
REQ |
Bean Validation 2.0 |
Y |
Y |
Y |
REQ |
Managed Beans 1.0 |
Y |
Y |
Y |
REQ |
Interceptors 1.2 |
Y |
Y |
Y |
REQ |
Contexts and Dependency Injection 2.0 |
Y |
Y |
Y |
REQ |
Dependency Injection 1.0 |
Y |
Y |
Y |
REQ |
All classes and interfaces required by the specifications for the APIs must be provided by the Jakarta EE containers indicated above. In some cases, a Jakarta EE product is not required to provide objects that implement interfaces intended to be implemented by an application server, nevertheless, the definitions of such interfaces must be included in the Jakarta EE platform. If an implementation includes support for a technology marked as Optional, that technology must be supported in the containers specified above. If a product implementation does not support a technology marked as Optional, it must not include the APIs for that technology.[18]
6.1.3. Pruned Java Technologies
As the Jakarta EE specification has evolved, some of the technologies originally included in Jakarta EE are no longer as relevant as they were when they were introduced to the platform. The Jakarta EE expert group follows a process first defined by the Java SE expert group ( http://mreinhold.org/blog/removing-features ) to prune technologies from the platform in a careful and orderly way that minimizes the impact to developers using these technologies, while allowing the platform to grow even stronger. In short, the process defines two steps:
-
The Umbrella Expert Group (UEG) for release N of the platform decides to propose that a particular feature be removed. The specification for that release documents the proposal.
-
The UEG for release N+1 decides whether to remove the feature from that release, retain it as a required component, or leave it in the "proposed removal" state for the next UEG to decide.
The result of successfully applying this policy to a feature is not the actual deletion of the feature but rather the conversion of the feature from a required component of the platform into an optional component. No actual removal from the specification occurs, although the feature may be removed from products at the choice of the product vendor.
Technologies that have been pruned as of Jakarta EE 8 are marked Optional in Jakarta EE Technologies. Technologies that may be pruned in a future release are marked Proposed Optional in Jakarta EE Technologies.
6.2. Java Platform, Standard Edition (Java SE) Requirements
6.2.1. Programming Restrictions
The Jakarta EE programming model divides responsibilities between Application Component Providers and Jakarta EE Product Providers: Application Component Providers focus on writing business logic and the Jakarta EE Product Providers focus on providing a managed system infrastructure in which the application components can be deployed.
This division leads to a restriction on the functionality that application components can contain. If application components contain the same functionality provided by Jakarta EE system infrastructure, there are clashes and mis-management of the functionality.
For example, if enterprise beans were allowed to manage threads, the Jakarta EE platform could not manage the life cycle of the enterprise beans, and it could not properly manage transactions.
Since we do not want to subset the Java SE platform, and we want Jakarta EE Product Providers to be able to use Java SE products without modification in the Jakarta EE platform, we use the Java SE security permissions mechanism to express the programming restrictions imposed on Application Component Providers.
In this section, we specify the Java SE security permissions that the Jakarta EE Product Provider must provide for each application component type. We call these permissions the Jakarta EE security permissions set. The Jakarta EE security permissions set is a required part of the Jakarta EE API contract. We also specify the set of permissions that the Jakarta EE Product Provider must be able to restrict from being provided to application components. In addition, we specify the means by which application component providers may declare the need for specific permissions and how these declarations must be processed by Jakarta EE products.
The Java SE security permissions are fully described in http://docs.oracle.com/javase/8/docs/technotes/guides/security/permissions.html .
6.2.2. Jakarta EE Security Manager Related Requirements
Every Jakarta EE product must be capable of running with a Java security manager that enforces Java security permissions and that prevents application components from performing operations for which they have not been provided the required permissions.
6.2.2.1. Jakarta EE Product Provider’s Responsibilities
A Jakarta EE product may allow application components to run without a security manager, but every Jakarta EE product must be capable of running application components with a security manager that enforces security permissions, as described below.
The set of security permissions provided to application components by a particular installation is a matter of policy outside the scope of this specification, however, every Jakarta EE product must be capable of running with a configuration that provides application classes and packaged libraries the permissions defined in Jakarta EE Security Permissions Set.
All Jakarta EE products must allow the set of permissions available to application classes in a module to be configurable, providing application components in some modules with different permissions than those described in Jakarta EE Security Permissions Set.
As defined in Declaring Permissions Required by Application Components,” a component provider may declare the permissions required by the application classes and libraries packaged in a module. When a component provider has declared the permissions required by a module, on successful deployment of the module, at least the declared permissions must have been granted to the application classes and libraries packaged in the module. If security permissions are declared that conflict with the policy of the product installation, the Jakarta EE product must fail deployment of the application module. If an application module does not contain a declaration of required security permissions and deployment otherwise succeeds, the Jakarta EE product must grant the application classes and libraries the permissions established by the security policy of the installation. The Jakarta EE product must ensure that the system administrator for the installation be able to define the security policy for the installation to include the permissions in Jakarta EE Security Permissions Set.
Note that, on some installations of Jakarta EE products, the security policy of the installation may be such that applications are granted fewer permissions than those defined in
Jakarta EE Security Permissions Set and, as a result, some applications that declare only the permissions defined in Jakarta EE Security Permissions Set may not be deployable. Other applications that require the same permissions but do not declare them may deploy but will encounter runtime failures when the missing permission is required by the application component.
Every Jakarta EE product must be capable of running with a Java security manager and with an installation policy that does not grant the permissions described in Restrictable Jakarta EE Security Permissions to Web, enterprise beans, and resource adapter components. That environment must otherwise fully support the requirements of this specification.
6.2.2.2. Application Component Provider’s Responsibilities
To ensure that application deployment will only succeed if required permissions are compatible with security policy of the installation environment, application component providers should declare all Java security permissions required by their application components.
Declaring Permissions Required by Application Components,” defines the mechanism(s) by which required permissions may be declared.
Note that, while FilePermissions or SocketPermissions for specific resources may be granted as a result of application components declaring them as required, the local operating system or network security policy may restrict access to the requested resources. This may result in a runtime failure to access these resources even though deployment of the application has succeeded.
6.2.2.3. System Administrator’s Responsibilities
Security policy requirements differ from one installation environment to another. The system administrator is responsible for configuring the permissions available to application modules to meet the security policy requirements of the installation environment. For example, cloud environments may require greater restrictions on the system resources available to applications than on-premise enterprise installations. Note that restricting the permissions beyond those in Jakarta EE Security Permissions Set may prevent some applications from working correctly.
Care should be taken by the system administrator to ensure that resources that are expected to be available to application components are appropriately represented in the security policy of the operational environment.
In particular, the temporary file directory made available through the ServletContext attribute javax.servlet.context.tempdir should be available to deployed applications. The security policy of the operational environment should grant the application server process access to the corresponding part of the file system. The Jakarta EE Product must be capable of using the security manager to enforce that an application only has access to the part of the filesystem namespace named by the javax.security.context.tempdir attribute, and that that part of the filesystem namespace is separate from the corresponding filesystem namespace available to other applications.
6.2.2.4. Listing of the Jakarta EE Security Permissions Set
Jakarta EE Security Permissions Set lists the Java permissions that Jakarta EE components (by type) can reliably be granted by a Jakarta EE product, given appropriate local installation configuration.
Security Permissions | Target | Action |
---|---|---|
Application Clients |
||
java.awt.AWTPermission |
accessClipboard |
|
java.awt.AWTPermission |
accessEventQueue |
|
java.awt.AWTPermission |
showWindowWithout WarningBanner |
|
java.lang.RuntimePermission |
exitVM |
|
java.lang.RuntimePermission |
loadLibrary.* |
|
java.lang.RuntimePermission |
queuePrintJob |
|
java.net.SocketPermission |
* |
connect |
java.net.SocketPermission |
localhost:1024- |
accept,listen |
java.io.FilePermission |
* |
read,write |
java.util.PropertyPermission |
* |
read |
Applet Clients |
||
java.net.SocketPermission |
codebase |
connect |
java.util.PropertyPermission |
limited |
read |
Web, Enterprise Beans, and Resource Adapter Components |
||
java.lang.RuntimePermission |
loadLibrary.* |
|
java.lang.RuntimePermission |
queuePrintJob |
|
java.net.SocketPermission |
* |
connect |
java.io.FilePermission |
* |
read,write [19] |
java.io.FilePermission |
file:${javax.servlet.context.tempdir} |
read, write [20] |
java.util.PropertyPermission |
* |
read |
6.2.2.5. Restrictable Jakarta EE Security Permissions
Restrictable Jakarta EE Security Permissions lists the Java permissions that a Jakarta EE product must be capable of restricting when running a Web or Enterprise Beans application component. If the Target field is empty, a Jakarta EE product must be capable of deploying application modules such that no instances of that permission are granted to the components in the application module.
Security Permissions | Target | Action |
---|---|---|
Web, Enterprise Beans, and Resource Adapter Components |
||
java.security.AllPermission |
||
java.security.SecurityPermission |
||
java.security.UnresolvedPermission |
||
java.awt.AWTPermission |
||
java.io.SerializablePermission |
||
java.lang.reflect.ReflectPermission |
||
java.lang.RuntimePermission |
<any except loadLibrary.* and queuePrintJob> [21] |
|
java.net.NetPermission |
||
java.sql.SQLPermission |
||
java.util.PropertyPermission |
<any> |
write [22] |
java.util.logging.LoggingPermission |
||
javax.net.ssl.SSLPermission |
||
java.security.auth.AuthPermission |
||
java.security.auth.PrivateCredentialPermission |
||
java.security.auth.kerberos.DelegationPermission |
||
java.security.auth.kerberos.ServicePermission |
||
javax.sound.sampled.AudioPermission |
6.2.2.6. Declaring Permissions Required by Application Components
By declaring the permissions required by an application as described in this section, an application component provider is ensured, through the successful deployment of his or her application, that the Jakarta EE Product has granted at least the declared permissions to the classes and libraries packaged in the application module.
Since the specific set of permissions granted to a successfully deployed application is a function of the security policy for the installation and the permissions declared within the permissions.xml files, the application component provider is ensured that the effective permission set consists of at least those permissions that are declared within the application.
Permission declarations must be stored in META-INF/permissions.xml file within an enterprise beans, web, application client, or resource adapter archive in order for them to be located and subsequently processed by the deployment machinery of the Jakarta EE Product. The Jakarta EE Product is not required to support permissions.xml files that specify permission classes that are packaged in the application.
The permissions for a packaged library are the same as the permissions for the module. Thus, if a library is packaged in a .war file, it gets the permissions of the .war file.
For applications packaged in an .ear file, the declaration of permissions must be at .ear file level. This permission set is applied to all modules and libraries packaged within the .ear file or within its contained modules. Any permissions.xml files within such packaged modules are ignored, regardless of whether a permissions.xml file has been supplied for the .ear file itself.
The fact that these permission declarations are being made from within the context of a particular application implies the codeBase(s) to which the grant should be made. This simplifies the syntax that is needed to just the Permission class name and two String arguments. This aligns the declaration syntax with the default policy language and the constructor signature for permissions that is compliant with the default policy syntax.
permission <class> [<name> [, <action list>]];
The following is an example of a permission set declaration:
... <permissions> <permission> <class-name>java.io.FilePermission</class-name> <name>/tmp/abc</name> <actions>read,write</actions> </permission> <permission> <class-name>java.lang.RuntimePermission</class-name> <name>createClassLoader</name> </permission> </permissions> ...
The Jakarta EE permissions XML Schema is located at http://xmlns.jcp.org/xml/ns/javaee/permissions_8.xsd .
6.2.3. Additional Requirements
6.2.3.1. Networking
The Java SE platform includes a pluggable mechanism for supporting multiple URL protocols through the java.net.URLStreamHandler class and the java.net.URLStreamHandlerFactory interface.
The following URL protocols must be supported:
-
file : Only reading from a file URL need be supported. That is, the corresponding URLConnection object’s getOutputStream method may fail with an UnknownServiceException . File access is restricted according to the permissions described above.
-
http : Version 1.1 of the HTTP protocol must be supported. An http URL must support both input and output.
-
https : SSL version 3.0 and TLS version 1.2 must be supported by https URL objects. Both input and output must be supported.
The Java SE platform also includes a mechanism for converting a URL’s byte stream to an appropriate object, using the java.net.ContentHandler class and java.net.ContentHandlerFactory interface. A ContentHandler object can convert a MIME byte stream to an object. ContentHandler objects are typically accessed indirectly using the getContent method of URL and URLConnection .
When accessing data of the following MIME types using the getContent method, objects of the corresponding Java type listed in Java Type of Objects Returned When Using the getContent Method must be returned.
MIME Type | Java Type |
---|---|
image/gif |
java.awt.Image |
image/jpeg |
java.awt.Image |
image/png |
java.awt.Image |
Many environments will use HTTP proxies rather than connecting directly to HTTP servers. If HTTP proxies are being used in the local environment, the HTTP support in the Java SE platform should be configured to use the proxy appropriately. Application components must not be required to configure proxy support in order to use an http URL.
Most enterprise environments will include a firewall that limits access from the internal network (intranet) to the public Internet, and vice versa. It is typical for access using the HTTP protocol to pass through such firewalls, perhaps by using proxy servers. It is not typical that general TCP/IP traffic, including RMI-JRMP, and RMI-IIOP, can pass through firewalls.
These considerations have implications on the use of various protocols to communicate between application components. This specification requires that HTTP access through firewalls be possible where local policy allows. Some Jakarta EE products may provide support for tunneling other communication through firewalls, but this is neither specified nor required. Application developers should consider the impact of these issues in the design of applications, particularly in view of cloud environments, where a cloud platform provider might only allow HTTP-based access.
6.2.3.2. JDBC™ API
The JDBC API, which is part of the Java SE platform, allows for access to a wide range of data storage systems. The Java SE platform, however, does not require that a system meeting the Java Compatible™ quality standards provide a database that is accessible through the JDBC API.
To allow for the development of portable applications, the Jakarta EE specification does require that such a database be available and accessible from a Jakarta EE product through the JDBC API. Such a database must be accessible from web components, enterprise beans, and application clients, but need not be accessible from applets. In addition, the driver for the database must meet the JDBC Compatible requirements in the JDBC specification.
Jakarta EE applications should not attempt to load JDBC drivers directly. Instead, they should use the technique recommended in the JDBC specification and perform a JNDI lookup to locate a DataSource object. The JNDI name of the DataSource object should be chosen as described in Resource Manager Connection Factory References.” The Jakarta EE platform must be able to supply a DataSource that does not require the application to supply any authentication information when obtaining a database connection. Of course, applications may also supply a user name and password when connecting to the database.
When a JDBC API connection is used in an enterprise bean , the transaction characteristics will typically be controlled by the container. The component should not attempt to change the transaction characteristics of the connection, commit the transaction, roll back the transaction, or set autocommit mode. Attempts to make changes that are incompatible with the current transaction context may result in a SQLException being thrown. The Jakarta Enterprise Beans specification contains the precise rules for enterprise beans.
Note that the same restrictions apply when a component creates a transaction using the Jakarta Transactions UserTransaction interface. The component should not attempt the operations listed above on the JDBC Connection object that would conflict with the transaction context.
Drivers supporting the JDBC API in a Jakarta EE environment must meet the JDBC API Compliance requirements as specified in the JDBC specification.
The JDBC API includes APIs for connection naming via JNDI, connection pooling, and distributed transaction support. The connection pooling and distributed transaction features are intended for use by JDBC drivers to coordinate with an application server. Jakarta EE products are not required to support the application server facilities described by these APIs, although they may prove useful.
The Connector architecture defines an SPI that essentially extends the functionality of the JDBC SPI with additional security functionality, and a full packaging and deployment functionality for resource adapters. A Jakarta EE product that supports the Connector architecture must support deploying and using a JDBC driver that has been written and packaged as a resource adapter using the Connector architecture.
The JDBC 4.2 specification is available at https://jcp.org/en/jsr/detail?id=221 .
6.2.3.3. Jakarta API for XML Web Services (JAX-WS) Requirements
The JAX-WS specification provides support for web services that use the JAXB API for binding XML data to Java objects. The JAX-WS specification defines client APIs for accessing web services as well as techniques for implementing web service endpoints. The Web Services for Jakarta EE specification describes the deployment of JAX-WS-based services and clients. The Enterprise Beans and Servlet specifications also describe aspects of such deployment. It must be possible to deploy JAX-WS-based applications using any of these deployment models.
The JAX-WS specification describes the support for message handlers that can process message requests and responses. In general, these message handlers execute in the same container and with the same privileges and execution context as the JAX-WS client or endpoint component with which they are associated. These message handlers have access to the same JNDI java:comp/env namespace as their associated component. Custom serializers and deserializers, if supported, are treated in the same way as message handlers.
The JAX-WS specification is available at http://jcp.org/en/jsr/summary?id=224 .
6.2.3.4. Java IDL (Proposed Optional)
The requirements in this section only apply to Jakarta EE products that support interoperability using CORBA.
Java IDL allows applications to access any CORBA object, written in any language, using the standard IIOP protocol. The Jakarta EE security restrictions typically prevent all application component types except application clients from creating and exporting a CORBA object, but all Jakarta EE application component types can be clients of CORBA objects.
A Jakarta EE product must support Java IDL as defined by chapters 1 - 8, 13, and 15 of the CORBA 2.3.1 specification, available at http://www.omg.org/cgi-bin/doc?formal/99-10-07 , and the IDL To Java Language Mapping Specification, available at http://www.omg.org/cgi-bin/doc?ptc/2000-01-08 .
The IIOP protocol supports the ability to multiplex calls over a single connection. All Jakarta EE products must support requests from clients that multiplex calls on a connection to either Java IDL server objects or RMI-IIOP server objects (such as enterprise beans). The server must allow replies to be sent in any order, to avoid deadlocks where one call would be blocked waiting for another call to complete. Jakarta EE clients are not required to multiplex calls, although such support is highly recommended.
A Jakarta EE product must provide support for a CORBA Portable Object Adapter (POA) to support portable stub, skeleton, and tie classes. A Jakarta EE application that defines or uses CORBA objects other than enterprise beans must include such portable stub, skeleton, and tie classes in the application package.
Jakarta EE applications need to use an instance of org.omg.CORBA.ORB to perform many Java IDL and RMI-IIOP operations. The default ORB returned by a call to ORB.init(new String[0], null) must be usable for such purposes; an application need not be aware of the implementation classes used for the ORB and RMI-IIOP support.
In addition, for performance reasons it is often advantageous to share an ORB instance among components in an application. To support such usage, all web, enterprise bean, and application client containers are required to provide an ORB instance in the JNDI namespace under the name java:comp/ORB . The container is allowed, but not required, to share this instance between components. The container may also use this ORB instance itself. To support isolation between applications, an ORB instance should not be shared between components in different applications. To allow this ORB instance to be safely shared between components, portable components must restrict their usage of certain ORB APIs and functionality:
-
Do not call the ORB shutdown method.
-
Do not call the org.omg.CORBA_2_3.ORB methods register_value_factory and unregister_value_factory with an id used by the container.
A Jakarta EE product must provide a COSNaming service to support the Jakarta Enterprise Beans interoperability requirements. It must be possible to access this COSNaming service using the Java IDL COSNaming APIs. Applications with appropriate privileges must be able to lookup objects in the COSNaming service. COSNaming is defined in the Interoperable Naming Service specification, available at http://www.omg.org/cgi-bin/doc?formal/2000-06-19 .
6.2.3.5. RMI-JRMP
JRMP is the Java technology-specific Remote Method Invocation (RMI) protocol. The Jakarta EE security restrictions typically prevent all application component types except application clients from creating and exporting an RMI object, but all Jakarta EE application component types can be clients of RMI objects.
6.2.3.6. RMI-IIOP (Proposed Optional)
The requirements in this section only apply to Jakarta EE products that include an Enterprise Beans container and support interoperability using RMI-IIOP.
RMI-IIOP allows objects defined using RMI style interfaces to be accessed using the IIOP protocol. It must be possible to make any remote enterprise bean accessible via RMI-IIOP. Some Jakarta EE products will simply make all remote enterprise beans always (and only) accessible via RMI-IIOP; other products might control this via an administrative or deployment action. These and other approaches are allowed, provided that any remote enterprise bean (or by extension, all remote enterprise beans) can be made accessible using RMI-IIOP.
Components accessing remote enterprise beans may need to use the narrow method of the javax.rmi.PortableRemoteObject class, under circumstances described in the Jakarta Enterprise Beans specification. Because remote enterprise beans may be deployed using other RMI protocols, portable applications must not depend on the characteristics of RMI-IIOP objects (for example, the use of the Stub and Tie base classes) beyond what is specified in the Jakarta Enterprise Beans specification.
The Jakarta EE security restrictions typically prevent all application component types, except application clients, from creating and exporting an RMI-IIOP object. All Jakarta EE application component types can be clients of RMI-IIOP objects. Jakarta EE applications should also use JNDI to lookup non-Enterprise Beans RMI-IIOP objects. The JNDI names used for such non-Enterprise Beans RMI-IIOP objects should be configured at deployment time using the standard environment entries mechanism (see JNDI Naming Context”). The application should fetch a name from JNDI using an environment entry, and use the name to lookup the RMI-IIOP object. Typically such names will be configured to be names in the COSNaming name service.
This specification does not provide a portable way for applications to bind objects to names in a name service. Some products may support use of JNDI and COSNaming for binding objects, but this is not required. Portable Jakarta EE application clients can create non-Enterprise Beans RMI-IIOP server objects for use as callback objects, or to pass in calls to other RMI-IIOP objects.
Note that while RMI-IIOP doesn’t specify how to propagate the current security context or transaction context, the Jakarta Enterprise Beans interoperability specification does define such context propagation. This specification only requires that the propagation of context information as defined in the Jakarta Enterprise Beans specification be supported in the use of RMI-IIOP to access enterprise beans. The propagation of context information is not required in the uses of RMI-IIOP to access objects other than enterprise beans.
The RMI-IIOP specification describes how portable Stub and Tie classes can be created. To be portable to all implementations that use a CORBA Portable Object Adapter (POA), the Tie classes must extend the org.omg.PortableServer.Servant class. This is typically done by using the -poa option to the rmic command. A Jakarta EE product must provide support for these portable Stub and Tie classes, typically using the required CORBA POA. However, for portability to systems that do not use a POA to implement RMI-IIOP, applications should not depend on the fact that the Tie extends the Servant class. A Jakarta EE application that defines or uses RMI-IIOP objects other than enterprise beans must include such portable Stub and Tie classes in the application package. Stub and Tie objects for enterprise beans, however, must not be included with the application: they will be generated, if needed, by the Jakarta EE product at deployment time or at run time.
RMI-IIOP is defined by chapters 5, 6, 13, 15, and section 10.6.2 of the CORBA 2.3.1 specification, available at http://www.omg.org/cgi-bin/doc?formal/99-10-07 , and by the Java™ Language To IDL Mapping Specification, available at http://www.omg.org/cgi-bin/doc?ptc/2000-01-06 .
6.2.3.7. JNDI
A Jakarta EE product that supports the following types of objects must be able to make them available in the application’s JNDI namespace: EJBHome objects, EJBLocalHome objects, Enterprise Beans business interface objects, Jakarta Transactions UserTransaction objects, JDBC API DataSource objects, JMS ConnectionFactory and Destination objects, JavaMail Session objects, URL objects, resource manager ConnectionFactory objects (as specified in the Connector specification), ORB objects, EntityManagerFactory objects, and other Java language objects as described in Resources, Naming, and Injection.” The JNDI implementation in a Jakarta EE product must be capable of supporting all of these uses in a single application component using a single JNDI InitialContext . Application components will generally create a JNDI InitialContext using the default constructor with no arguments. The application component may then perform lookups on that InitialContext to find objects as specified above.
The names used to perform lookups for Jakarta EE objects are application dependent. The application component’s metadata annotations and/or deployment descriptor are used to list the names and types of objects expected. The Deployer configures the JNDI namespace to make appropriate components available. The JNDI names used to lookup such objects must be in the JNDI java: namespace. See Resources, Naming, and Injection” for details.
Particular names are defined by this specification for the cases when the Jakarta EE product includes the corresponding technology. For all application components that have access to the Jakarta Transaction UserTransaction interface, the appropriate UserTransaction object can be found using the name java:comp/UserTransaction . In all containers except the applet container, application components may lookup a CORBA ORB instance using the name java:comp/ORB . For all application components that have access to the CDI BeanManager interface, the appropriate BeanManager object can be found using the name java:comp/BeanManager . For all application components that have access to the Validation APIs, the appropriate Validator and ValidatorFactory objects can be found using the names java:comp/Validator and java:comp/ValidatorFactory respectively.
The name used to lookup a particular Jakarta EE object may be different in different application components. In general, JNDI names can not be meaningfully passed as arguments in remote calls from one application component to another remote component (for example, in a call to an enterprise bean ).
The JNDI java: namespace is commonly implemented as symbolic links to other naming systems. Different underlying naming services may be used to store different kinds of objects, or even different instances of objects. It is up to a Jakarta EE product to provide the necessary JNDI service providers for accessing the various objects defined in this specification.
This specification requires that the Jakarta EE platform provide the ability to perform lookup operations as described above. Different JNDI service providers may provide different capabilities, for instance, some service providers may provide only read-only access to the data in the name service.
A Jakarta EE product may be required to provide a COSNaming name service to meet the Jakarta Enterprise Beans interoperability requirements. In such a case, a COSNaming JNDI service provider must be available through the web, Enterprise Beans, and application client containers. It will also typically be available in the applet container, but this is not required.
A COSNaming JNDI service provider is a part of the Java SE 8 SDK and JRE from Oracle, but is not a required component of the Java SE specification. The COSNaming JNDI service provider specification is available at http://docs.oracle.com/javase/8/docs/technotes/guides/jndi/jndi-cos.html .
See Resources, Naming, and Injection” for the complete naming requirements for the Jakarta EE platform. The JNDI specification is available at http://docs.oracle.com/javase/8/docs/technotes/guides/jndi/index.html .
6.2.3.8. Context Class Loader
This specification requires that Jakarta EE containers provide a per thread context class loader for the use of system or library classes in dynamically loading classes provided by the application. The Jakarta Enterprise Beans specification requires that all Jakarta Enterprise Beans client containers provide a per thread context class loader for dynamically loading system value classes. The per thread context class loader is accessed using the Thread method getContextClassLoader .
The classes used by an application will typically be loaded by a hierarchy of class loaders. There may be a top level application class loader, an extension class loader, and so on, down to a system class loader. The top level application class loader delegates to the lower class loaders as needed. Classes loaded by lower class loaders, such as portable Jakarta Enterprise Beans system value classes, need to be able to discover the top level application class loader used to dynamically load application classes.
This specification requires that containers provide a per thread context class loader that can be used to load top level application classes as described above. See Dynamic Class Loading” for recommendations for libraries that dynamically load classes.
6.2.3.9. Jakarta Authentication Requirements
All enterprise beans containers and all web containers must support the use of the Jakarta Authentication APIs as specified in the Connector specification. All application client containers must support use of the Jakarta Authentication APIs.
The Jakarta Authentication specification is available at https://jakarta.ee/specifications/authentication .
6.2.3.10. Logging API Requirements
The Logging API provides classes and interfaces in the java.util.logging package that are the Java™ platform’s core logging facilities. This specification does not require any additional support for logging. A Jakarta EE application typically will not have the LoggingPermission necessary to control the logging configuration, but may use the logging API to produce log records. A future version of this specification may require that the Jakarta EE containers use the logging API to log certain events.
6.2.3.11. Preferences API Requirements
The Preferences API in the java.util.prefs package allows applications to store and retrieve user and system preference and configuration data. A Jakarta EE application typically will not have the RuntimePermission("preferences") necessary to use the Preferences API. This specification does not define any relationship between the principal used by a Jakarta EE application and the user preferences tree defined by the Preferences API. A future version of this specification may define the use of the Preferences API by Jakarta EE applications.
6.3. Jakarta Enterprise Beans 3.2 Requirements
This specification requires that a Jakarta EE product provide support for enterprise beans as specified in the Jakarta Enterprise Beans specification. The Jakarta Enterprise Beans specification is available at https://jakarta.ee/specifications/enterprise-beans .
This specification does not impose any additional requirements at this time. Note that the Jakarta Enterprise Beans specification includes the specification of the Jakarta Enterprise Beans interoperability protocol based on RMI-IIOP. Support for the Jakarta Enterprise Beans interoperability protocol is Proposed Optional in Jakarta EE 8. All containers that support Jakarta Enterprise Beans clients must be capable of using the Jakarta Enterprise Beans interoperability protocol to invoke enterprise beans. All Jakarta Enterprise Beans containers must support the invocation of enterprise beans using the Jakarta Enterprise Beans interoperability protocol. A Jakarta EE product may also support other protocols for the invocation of enterprise beans.
A Jakarta EE product may support multiple object systems (for example, RMI-IIOP and RMI-JRMP). It may not always be possible to pass object references from one object system to objects in another object system. However, when an enterprise bean is using the RMI-IIOP protocol, it must be possible to pass object references for RMI-IIOP or Java IDL objects as arguments to methods on such an enterprise bean, and to return such object references as return values of a method on such an enterprise bean. In addition, it must be possible to pass a reference to an RMI-IIOP-based enterprise bean’s Home or Remote interface to a method on an RMI-IIOP or Java IDL object, or to return such an enterprise bean object reference as a return value from such an RMI-IIOP or Java IDL object.
In a Jakarta EE product that includes both an enterprise beans container and a web container, both containers are required to support access to local enterprise beans. No support is provided for access to local enterprise beans from the application client container or the applet container.
6.4. Jakarta Servlet 4.0 Requirements
The Jakarta Servlet specification defines the packaging and deployment of web applications, whether standalone or as part of a Jakarta EE application. The Servlet specification also addresses security, both standalone and within the Jakarta EE platform. These optional components of the Servlet specification are requirements of the Jakarta EE platform.
The Servlet specification includes additional requirements for web containers that are part of a Jakarta EE product and a Jakarta EE product must meet these requirements as well.
The Servlet specification defines distributable web applications. To support Jakarta EE applications that are distributable, this specification adds the following requirements.
Web containers must support Jakarta EE distributable web applications placing objects of any of the following types (when supported by the Jakarta EE product) into a javax.servlet.http.HttpSession object using the setAttribute or putValue methods:
java.io.Serializable
-
javax.ejb.EJBObject
-
javax.ejb.EJBHome
-
javax.ejb.EJBLocalObject
-
javax.ejb.EJBLocalHome
-
javax.transaction.UserTransaction
-
a javax.naming.Context object for the java:comp/env context
a reference to an Enterprise Bean local or remote business interface or no-interface view
Web containers may support objects of other types as well. Web containers must throw a java.lang.IllegalArgumentException if an object that is not one of the above types, or another type supported by the container, is passed to the setAttribute or putValue methods of an HttpSession object corresponding to a Jakarta EE distributable session. This exception indicates to the programmer that the web container does not support moving the object between VMs. A web container that supports multi-VM operation must ensure that, when a session is moved from one VM to another, all objects of supported types are accurately recreated on the target VM.
The Servlet specification defines access to local enterprise beans as an optional feature. This specification requires that all Jakarta EE products that include both a web container and an Enterprise Beans container provide support for access to local enterprise beans from the web container.
The Jakarta Servlet specification is available at https://jakarta.ee/specifications/servlet .
6.5. Jakarta Server Pages 2.3 Requirements
The Jakarta Server Pages specification depends on and builds on the servlet framework. A Jakarta EE product must support the entire Jakarta Server Pages specification.
The Jakarta Server Pages specification is available at https://jakarta.ee/specifications/pages .
6.6. Jakarta Expression Language (EL) 3.0 Requirements
The Jakarta Expression Language specification was formerly a part of the Jakarta Server Pages specification. It was split off into its own specification so that it could be used independently of Jakarta Server Pages. A Jakarta EE product must support the Expression Language.
The Jakarta Expression Language specification is available at https://jakarta.ee/specifications/expression-language .
6.7. Jakarta Messaging 2.0 Requirements
A Jakarta Messaging provider must be included in a Jakarta EE product that requires support for Jakarta Messaging. The Jakarta Messaging implementation must provide support for both Jakarta Messaging point-to-point and publish/subscribe messaging, and thus must make those facilities available using the ConnectionFactory and Destination APIs.
The Jakarta Messaging specification defines several interfaces intended for integration with an application server. A Jakarta EE product need not provide objects that implement these interfaces, and portable Jakarta EE applications must not use the following interfaces:
-
javax.jms.ServerSession
-
javax.jms.ServerSessionPool
-
javax.jms.ConnectionConsumer
all javax.jms XA interfaces
The following methods may only be used by application components executing in the application client container:
-
javax.jms.MessageConsumer method getMessageListener
-
javax.jms.MessageConsumer method setMessageListener
-
javax.jms.JMSConsumer method getMessageListener
-
javax.jms.JMSConsumer method setMessageListener
-
javax.jms.Connection method setExceptionListener
-
javax.jms.Connection method stop
-
javax.jms.Connection method setClientID
-
javax.jms.JMSContext method stop
-
javax.jms.JMSContext method setClientID
-
javax.jms.JMSContext method setExceptionListener
-
javax.jms.JMSContext method createContext
-
javax.jms.Producer method setAsync
-
javax.jms.MessageProducer method send(Message message, CompletionListener completionListener)
-
javax.jms.MessageProducer method send(Message message, int deliveryMode, int priority, long timeToLive, CompletionListener completionListener)
-
javax.jms.MessageProducer method send(Destination destination, Message message, CompletionListener completionListener)
-
javax.jms.MessageProducer method send(Destination destination, Message message, int deliveryMode, int priority, long timeToLive, CompletionListener completionListener)
The following methods may only be used by application components executing in the application client container. Note, however, that these methods provide an expert facility not used by ordinary applications. See the JMS specification for further detail.
javax.jms.Session method setMessageListener
-
javax.jms.Session method getMessageListener
-
javax.jms.Session method run
-
javax.jms.Connection method createConnectionConsumer
-
javax.jms.Connection method createSharedConnectionConsumer
-
javax.jms.Connection method createDurableConnectionConsumer
javax.jms.Connection method createSharedDurableConnectionConsumer
A Jakarta EE container may throw a JMSException (if allowed by the method) or a JMSRuntimeException (if throwing a JMSException is not allowed by the method) if the application component violates any of the above restrictions.
Application components in the web and enterprise bean containers must not attempt to create more than one active (not closed) Session object per connection. An attempt to use the Connection object’s createSession method when an active Session object exists for that connection should be prohibited by the container. The container should throw a JMSException if the application component violates this restriction. An attempt to use the JMSContext object’s createContext method should be prohibited by the container. The container should throw a JMSRuntimeException , since the first JMSContext already contains a connection and session and this method would create a second session on the same connection. Application client containers must support the creation of multiple sessions for each connection.
The Jakarta Messaging specification defines further restrictions on the use of Jakarta Messaging in the Enterprise Beans and web containers. In general, the behavior of a Jakarta Messaging provider should be the same in both the enterprise beans container and the web container.
The Jakarta Messaging specification is available at _ https://jakarta.ee/specifications/messaging_ .
6.8. Jakarta Transaction 1.3 Requirements
Jakarta Transaction defines the UserTransaction interface that is used by applications to start, and commit or abort transactions. Application components get a UserTransaction object through a JNDI lookup using the name java:comp/UserTransaction or by requesting injection of a UserTransaction object.
Jakarta Transaction also defines the TransactionSynchronizationRegistry interface that can be used by system level components such as persistence managers to interact with the transaction manager. These components get a TransactionSynchronizationRegistry object through a JNDI lookup using the name java:comp/TransactionSynchronizationRegistry or by requesting injection of a TransactionSynchronizationRegistry object.
A number of interfaces defined by Jakarta Transaction are used by an application server to communicate with a transaction manager, and for a transaction manager to interact with a resource manager. These interfaces must be supported as described in the Connector specification. In addition, support for other transaction facilities may be provided transparently to the application by a Jakarta EE product.
The Jakarta Transaction specification is available at https://jakarta.ee/specifications/transactions .
6.9. Jakarta Mail 1.6 Requirements
The Jakarta Mail API allows for access to email messages contained in message stores, and for the creation and sending of email messages using a message transport. Specific support is included for Internet standard MIME messages. Access to message stores and transports is through protocol providers supporting specific store and transport protocols. The Jakarta Mail API specification does not require any specific protocol providers, but the JavaMail reference implementation includes an IMAP message store provider, a POP3 message store provider, and an SMTP message transport provider.
Configuration of the Jakarta Mail API is typically done by setting properties in a Properties object that is used to create a javax.mail.Session object using a static factory method. To allow the Jakarta EE platform to configure and manage JavaMail API sessions, an application component that uses the JavaMail API should request a Session object using JNDI, and should list its need for a Session object in its deployment descriptor using a resource-ref element, or by using a Resource annotation. A Jakarta Mail API Session object should be considered a resource factory, as described in Resource Manager Connection Factory References.” This specification requires that the Jakarta EE platform support javax.mail.Session objects as resource factories, as described in that section.
The Jakarta EE platform requires that a message transport be provided that is capable of handling addresses of type javax.mail.internet.InternetAddress and messages of type javax.mail.internet.MimeMessage . The default message transport must be properly configured to send such messages using the send method of the javax.mail.Transport class. Any authentication needed by the default transport must be handled without need for the application to provide a javax.mail.Authenticator or to explicitly connect to the transport and supply authentication information.
This specification does not require that a Jakarta EE product support any message store protocols.
Note that the Jakarta Mail API creates threads to deliver notifications of Store , Folder , and Transport events. The use of these notification facilities may be limited by the restrictions on the use of threads in various containers. In Enterprise Beans containers, for instance, it is typically not possible to create threads.
The Jakarta Mail API uses the JavaBeans Activation Framework API to support various MIME data types. The Jakarta Mail API must include javax.activation.DataContentHandlers for the following MIME data types, corresponding to the Java programming language type indicated in JavaMail API MIME Data Type to Java Type Mappings .
Mime Type | Java Type |
---|---|
text/plain |
java.lang.String |
text/html_ |
java.lang.String |
text/xml |
java.lang.String |
multipart/* |
javax.mail.internet.MimeMultipart |
message/rfc822 |
javax.mail.internet.MimeMessage |
The Jakarta Mail API specification is available at https://jakarta.ee/specifications/mail .
6.10. Jakarta EE Connectors 1.7 Requirements
In full Jakarta EE products, all Jakarta Enterprise Beans containers and all web containers must support the full set of Connector APIs. All such containers must support Resource Adapters that use any of the specified transaction capabilities. The Jakarta EE deployment tools must support deployment of Resource Adapters, as defined in the Connector specification, and must support the deployment of applications that use Resource Adapters.
The Jakarta EE Connectors specification is available at https://jakarta.ee/specifications/connectors .
6.11. Jakarta XML RPC 1.1 Requirements (Optional)
The Jakarta XML RPC specification defines client APIs for accessing web services as well as techniques for implementing web service endpoints. The Web Services for Jakarta EE specification describes the deployment of Jakarta XML RPC-based services and clients. The Jakarta Enterprise Beans and Servlet specifications also describe aspects of such deployment. In Jakarta EE products that support Jakarta XML RPC, it must be possible to deploy Jakarta XML RPC-based applications using any of these deployment models.
The Jakarta XML RPC specification describes the support for message handlers that can process message requests and responses. In general, these message handlers execute in the same container and with the same privileges and execution context as the Jakarta XML RPC client or endpoint component with which they are associated. These message handlers have access to the same JNDI java:comp/env namespace as their associated component. Custom serializers and deserializers, if supported, are treated in the same way as message handlers.
Note that neither web service annotations nor injection is supported for Jakarta XML RPC service endpoints and handlers. New applications are encouraged to use Jakarta XML Web Services to take advantage of these new facilities that make it easier to write web services.
The Jakarta XML RPC specification is available at https://jakarta.ee/specifications/xml-rpc .
6.12. Jakarta RESTful Web Services 2.1 Requirements
Jakarta RESTful Web Services defines APIs for the development of Web services built according to the Representational State Transfer (REST) architectural style.
In a full Jakarta EE product, all Jakarta EE web containers are required to support applications that use Jakarta RESTful Web Services technology.
The specification describes the deployment of services as a servlet. It must be possible to deploy Jakarta RESTful Web Services-based applications using this deployment model with the servlet-class element of the web.xml descriptor naming the application-supplied extension of the Jakarta RESTful Web Services Application abstract class.
The specification defines a set of optional container-managed facilities and resources that are intended to be available in a Jakarta EE container — all such features and resources must be made available.
The Jakarta RESTful Web Services specification is available at https://jakarta.ee/specifications/restful-ws .
6.13. Jakarta WebSocket 1.1 (WebSocket) Requirements
The Jakarta WebSocket (WebSocket) is a standard API for creating WebSocket applications. In a full Jakarta EE product, all Jakarta EE web containers are required to support the WebSocket API.
The Jakarta WebSocket specification can be found at https://jakarta.ee/specifications/websocket .
6.14. Jakarta JSON Processing 1.1 (JSON-P) Requirements
JSON (JavaScript Object Notation) is a lightweight data-interchange format used by many web services. The Jakarta JSON Processing (JSON-P) provides a convenient way to process (parse, generate, transform, and query) JSON text.
In a full Jakarta EE product, all Jakarta EE application client containers, web containers, and enterprise beans containers are required to support the JSON-P API.
The Jakarta JSON Processing specification can be found at https://jakarta.ee/specifications/jsonp .
6.15. Jakarta JSON Binding 1.0 (JSON-B) Requirements
The Jakarta JSON Binding API for JSON Binding (JSON-B) provides a convenient way to map between JSON text and Java objects.
In a full Jakarta EE product, all Jakarta EE application client containers, web containers, and enterprise beans containers are required to support the JSON-B API.
The Jakarta JSON Binding specification can be found at https://jakarta.ee/specifications/jsonb.
6.16. Jakarta Concurrency 1.1 (Concurrency Utilities) Requirements
Jakarta Concurrency Utilities for Jakarta EE is a standard API for providing asynchronous capabilities to Jakarta EE application components through the following types of objects: managed executor service, managed scheduled executor service, managed thread factory, and context service. In a full Jakarta EE product, all web containers and enterprise beans containers are required to support the Concurrency Utilities API. The Jakarta EE Product Provider must provide preconfigured default managed executor service, managed scheduled executor service, managed thread factory, and context service objects for use by the application in the containers in which the Concurrency Utilities API is required to be supported.
The Jakarta Concurrency specification can be found at https://jakarta.ee/specifications/concurrency .
6.17. Jakarta Batch 1.0 Specification Requirements
The Jakarta Batch provides a programming model for batch applications and a runtime for scheduling and executing jobs.
In a full Jakarta EE product, all Jakarta EE web containers and Jakarta Enterprise Beans containers are required to support the Batch API.
The Jakarta Batch specification can be found at https://jakarta.ee/specifications/batch .
6.18. Jakarta XML Registries 1.0 Requirements (Optional)
The Jakarta XML Registries specification defines APIs for client access to XML-based registries such as ebXML registries and UDDI registries. Jakarta EE products that support Jakarta XML Registries must include a Jakarta XML registry provider that meets at least the Jakarta XML Registries level 0 requirements.
The Jakarta XML Registries specification is available at https://jakarta.ee/specifications/xml-registries .
6.19. Jakarta Management 1.1 Requirements
Jakarta Management provides APIs for management tools to query a Jakarta EE application server to determine its current status, applications deployed, and so on. All Jakarta EE products must support this API as described in its specification.
The Jakarta Management specification is available at https://jakarta.ee/specifications/management .
6.20. Jakarta Deployment API 1.7 Requirements (Optional)
The Jakarta Deployment API defines the interfaces between the runtime environment of a deployment tool and plug-in components provided by a Jakarta EE application server. These plug-in components execute in the deployment tool and implement the Jakarta EE product-specific deployment mechanisms. Jakarta EE products that support the Jakarta Deployment API are required to supply these plug-in components for use in tools from other vendors.
Note that the Jakarta Deployment specification does not define new APIs for direct use by Jakarta EE applications. However, it would be possible to create a Jakarta EE application that acts as a deployment tool and provides the runtime environment required by the Jakarta Deployment The Jakarta EE Deployment API specification is available at https://jakarta.ee/specifications/deployment .
6.21. Jakarta Authorization 1.5 Requirements
The Jakarta Authorization specification defines a contract between a Jakarta EE application server and an authorization policy provider. In a full Jakarta EE product, all Jakarta EE web containers and enterprise bean containers are required to support this contract.
The Jakarta Authorization specification can be found at https://jakarta.ee/specifications/authorization .
6.22. Jakarta Authentication 1.1 Requirements
The Jakarta Authentication specification defines a service provider interface (SPI) by which authentication providers implementing message authentication mechanisms may be integrated in client or server message processing containers or runtimes. Authentication providers integrated through this interface operate on network messages provided to them by their calling container. They transform outgoing messages such that the source of the message may be authenticated by the receiving container, and the recipient of the message may be authenticated by the message sender. They authenticate incoming messages and return to their calling container the identity established as a result of the message authentication.
In a full Jakarta EE product, all Jakarta EE web containers and enterprise bean containers are required to support the baseline compatibility requirements as defined by the Jakarta Authentication specification. In a full Jakarta EE product, all web containers must also support the Servlet Container Profile as defined in the Jakarta Authentication specification. In a Jakarta EE profile product that includes Servlet and Jakarta Authentication, all web containers must also support the Servlet Container Profile as defined in the Jakarta Authentication specification. Support for the Jakarta Authentication SOAP Profile is not required.
The Jakarta Authentication specification can be found at https://jakarta.ee/specifications/authentication .
6.23. Jakarta Security 1.0 Requirements
Jakarta Security leverages Jakarta Authentication , but provides an easier to use SPI for authentication of users of web applications and defines identity store APIs for authentication and authorization.
In a full Jakarta EE product, all Jakarta EE web containers and enterprise bean containers are required to support the requirements defined by the Jakarta Security specification.
The Jakarta Security Specification can be found at https://jakarta.ee/specifications/security .
6.24. Jakarta Debugging Support for Other Languages Requirements 1.0
Jakarta Server Pages pages are usually translated into Java language pages and then compiled to create class files. The Jakarta Debugging Support for Other Languages specification describes information that can be included in a class file to relate class file data to data in the original source file. All Jakarta EE products are required to be able to include such information in class files that are generated from Jakarta Server Pages.
The Jakarta Debugging Support for Other Languages specification can be found at https://jakarta.ee/specifications/debugging .
6.25. Jakarta Standard Tag Library for Jakarta Server Pages 1.2 Requirements
Jakarta Standard Tag Library specification defines a standard tag library that makes it easier to develop Jakarta Server Pages Pages. All Jakarta EE products are required to provide a Jakarta Standard Tag Library for use by all Jakarta Server Pages.
The Jakarta Standard Tag Library for Jakarta Server Pages specification can be found at https://jakarta.ee/specifications/tags .
6.26. Jakarta Server Faces 2.3 Requirements
Jakarta Server Faces technology simplifies building user interfaces for Jakarta applications. Developers of various skill levels can quickly build web applications by: assembling reusable UI components in a page; connecting these components to an application data source; and wiring client-generated events to server-side event handlers. In a full Jakarta EE product, all Jakarta EE web containers are required to support applications that use the Jakarta Server Faces technology.
The Jakarta Server Faces specification can be found at https://jakarta.ee/specifications/faces .
6.27. Jakarta Annotations 1.3 Requirements
The Jakarta Annotations specification defines Java language annotations that are used by several other specifications, including this specification. The specifications that use these annotations fully define the requirements for these annotations. The applet container need not support any of these annotations. All other containers must provide definitions for all of these annotations, and must support the semantics of these annotations as described in the corresponding specifications and summarized in the following table.
Annotation | App Client | Web | Enterprise Beans |
---|---|---|---|
Resource |
Y |
Y |
Y |
Resources |
Y |
Y |
Y |
PostConstruct |
Y |
Y |
Y |
PreDestroy |
Y |
Y |
Y |
Generated |
N |
N |
N |
RunAs |
N |
Y |
Y |
DeclareRoles |
N |
Y |
Y |
RolesAllowed |
N |
Y |
Y |
PermitAll |
N |
Y |
Y |
DenyAll |
N |
Y |
Y |
ManagedBean |
Y |
Y |
Y |
DataSourceDefinition |
Y |
Y |
Y |
DataSourceDefinitions |
Y |
Y |
Y |
Priority |
Y |
Y |
Y |
The Jakarta Annotations specification can be found at https://jakarta.ee/specifications/annotations .
6.28. Jakarta Persistence 2.2 Requirements
Jakarta Persistence is the standard API for the management of persistence and object/relational mapping. The Jakarta Persistence specification provides an object/relational mapping facility for application developers using a Java domain model to manage a relational database.
As mandated by the Jakarta Persistence specification, in a Jakarta EE environment the classes of the persistence unit should not be loaded by the application class loader or any of its parent class loaders until after the entity manager factory for the persistence unit has been created.
The Jakarta Persistence specification can be found at https://jakarta.ee/specifications/persistence .
6.29. Bean Validation 2.0 Requirements
The Bean Validation specification defines a metadata model and API for JavaBean validation. The default metadata source is annotations, with the ability to override and extend the metadata through the use of XML validation descriptors.
The Jakarta EE platform requires that web containers make an instance of ValidatorFactory available to Jakarta Server Faces implementations by storing it in a servlet context attribute named javax.faces.validator.beanValidator.ValidatorFactory.
The Jakarta EE platform also requires that an instance of ValidatorFactory be made available to Jakarta Persistence providers as a property in the map that is passed as the second argument to the createContainerEntityManagerFactory(PersistenceUnitInfo, Map) method of the PersistenceProvider interface, under the name javax.persistence.validation.factory .
Additional requirements on Jakarta EE platform containers are specified in the Bean Validation specification, which can be found at https://jakarta.ee/specifications/bean-validation .
6.30. Managed Beans 1.0 Requirements
The Managed Beans specification defines a lightweight component model that supports the basic lifecycle model, resource injection facility and interceptor service present in the Jakarta EE platform.
The Managed Beans specification can be found at https://jakarta.ee/specifications/managed-beans .
6.31. Interceptors 1.2 Requirements
The Interceptors specification makes more generally available the interceptor facility originally defined as part of the Jakarta Enterprise Beans 3.0 specification.
The Interceptors specification can be found at https://jakarta.ee/specifications/interceptors .
6.32. Contexts and Dependency Injection for the Jakarta EE Platform 2.0 Requirements
The Contexts and Dependency Injection (CDI) specification defines a set of contextual services, provided by Jakarta EE containers, aimed at simplifying the creation of applications that use both web tier and business tier technologies.
The CDI specification can be found at https://jakarta.ee/specifications/cdi .
6.33. Dependency Injection for Java 1.0 Requirements
The Dependency Injection for Java (DI) specification defines a standard set of annotations (and one interface) for use on injectable classes.
In the Jakarta EE platform, support for Dependency Injection is mediated by CDI. See Support for Dependency Injection” for more detail.
The DI specification can be found at https://jakarta.ee/specifications/dependency-injection .
6.34. Enterprise Web Services 1.4 Requirements
The Enterprise Web Services specification defines the integration between the various Web Service technologies in Jakarta EE, including XML-RPC, XMl Web Services and XML Web Service Metadata.
The Enterprise Web Services specification can be found at https://jakarta.ee/specifications/enterprise-ws .
7. Interoperability
This chapter describes the interoperability requirements for the Jakarta™ EE Platform.
7.1. Introduction to Interoperability
The Jakarta EE platform will be used by enterprise environments that support clients of many different types. The enterprise environments will add new services to existing Enterprise Information Systems (EISs). They will be using various hardware platforms and applications written in various languages.
In particular, the Jakarta EE platform may be used in enterprise environments to bring together any of the following kinds of applications:
-
applications written in such languages as C++ and Visual Basic.
-
applications running on a personal computer platform, or Unix® workstation.
-
standalone Java™ technology-based applications that are not directly supported by the Jakarta EE platform.
It is the interoperability requirements of the Jakarta EE platform, set out in this chapter, that make it possible for it to provide indirect support for various types of clients, different hardware platforms, and a multitude of software applications. The interoperability features of the Jakarta EE platform permit the underlying disparate systems to work together seamlessly, while hiding much of the complexity required to join these pieces together.
The interoperability requirements for the current Jakarta EE platform release allow:
-
Jakarta EE applications to connect to legacy systems using CORBA or low-level socket interfaces.
-
Jakarta EE applications to connect to other Java Jakarta applications across multiple Jakarta EE products, whether from different Product Providers or from the same Provider, and multiple Jakarta EE platforms.
In this version of the specification, interoperability between Jakarta EE applications running in different platforms is accomplished through the HTTP protocol, possibly using SSL, or the Jakarta Enterprise Beans interoperability protocol based on IIOP.
7.2. Interoperability Protocols
This specification requires that a Jakarta EE product support a standard set of protocols and formats to ensure interoperability between Jakarta EE applications and with other applications that also implement these protocols and formats. The specification requires support for the following groups of protocols and formats:
-
Internet and web protocols
-
OMG protocols
-
Java technology protocols
-
Data formats
Most of these protocols and formats are supported by Java SE and by the underlying operating system.
7.2.1. Internet and Web Protocols
Standards based Internet protocols are the means by which different pieces of the platform communicate. The Jakarta EE platform typically supports the following Internet protocols, as described in the corresponding technology specifications:
-
TCP/IP protocol family—This is the core component of Internet communication. TCP/IP and UDP/IP are the standard transport protocols for the Internet. TCP/IP is supported by Java SE and the underlying operating system.
-
HTTP 1.1—This is the core protocol of web communication. As with TCP/IP, HTTP 1.1 is supported by Java SE and the underlying operating system. A Jakarta EE web container must be capable of advertising its HTTP services on the standard HTTP port, port 80.
-
HTTP/2—Server-side support for the HTTP/2 protocol is required by the Servlet specification.
-
SSL 3.0, TLS 1.2—SSL 3.0 (Secure Socket Layer) represents the security layer for Web communication. It is available indirectly when using the https URL as opposed to the http URL. A Jakarta EE web container must be capable of advertising its HTTPS service on the standard HTTPS port, port 443. Note that SSL 3.0 and only TLS 1.0 are required as part of the Jakarta Enterprise Beans interoperability protocol in the Jakarta Enterprise Beans specification.
-
SOAP 1.1—SOAP is a presentation layer protocol for the exchange of XML messages. Support for SOAP layered on HTTP is required, as described in the Jakarta XML-based RPC and Jakarta XML Web Services specifications.
-
SOAP 1.2—SOAP 1.2 is the version of the SOAP protocol standardized through W3C and supported by Jakarta XML Web Services.
-
WS-I Basic Profile 1.1—The WS-I Basic Profile, in combination with the Simple SOAP Binding Profile and Attachment Profile, describes interoperability requirements for the use of SOAP 1.1, WSDL 1.1, and MIME-based SOAP with Attachments. It is required by the Jakarta XML-based RPC and Jakarta XML Web Services specifications.
-
WebSocket protocol—The WebSocket protocol enables two-way communication layered over TCP. It enables bi-directional communication over a single connection established by an initial HTTP handshake and upgrade request. The WebSocket protocol has been standardized by IETF under RFC 6455.
7.2.2. OMG Protocols (Proposed Optional)
This specification requires the a full Jakarta EE product to support the following Object Management Group (OMG) based protocols:
-
IIOP (Internet Inter-ORB Protocol)—Supported by Java IDL and RMI-IIOP in Java SE. Java IDL provides standards-based interoperability and connectivity through the Common Object Request Broker Architecture (CORBA). CORBA specifies the Object Request Broker (ORB) which allows applications to communicate with each other regardless of location. This interoperability is delivered through IIOP, and is typically found in an intranet setting. IIOP can be used as an RMI protocol using the RMI-IIOP technology. IIOP is defined in Chapters 13 and 15 of the CORBA 2.3.1 specification, available at http://omg.org/cgi-bin/doc?formal/99-10-07 .
-
Jakarta Enterprise Beans interoperability protocol—The Jakarta Enterprise Beans interoperability protocol is based on IIOP (GIOP 1.2) and the CSIv2 CORBA Secure Interoperability specification. The Jakarta Enterprise Beans interoperability protocol is defined in the Jakarta Enterprise Beans specification.
-
CORBA Interoperable Naming Service protocol—The COSNaming-based INS protocol is an IIOP-based protocol for accessing a name service. The Jakarta Enterprise Beans interoperability protocol requires the use of the INS protocol for lookup of Jakarta Enterprise Beans objects using the JNDI API. In addition, it must be possible to use the Java IDL COSNaming API to access the INS name service. All Jakarta EE products must provide a name service that meets the requirements of the Interoperable Naming Service specification, available at http://omg.org/cgi-bin/doc?formal/2000-06-19 . This name service may be provided as a separate name server or as a protocol bridge or gateway to another name service. Either approach is consistent with this specification.
7.2.3. Java Technology Protocols
This specification requires the Jakarta EE platform to support the JRMP protocol, which is the Java technology-specific Remote Method Invocation (RMI) protocol. JRMP is a required component of Java SE and is one of two required RMI protocols. (IIOP is the other required RMI protocol, see above.)
JRMP is a distributed object model for the Java programming language. Distributed systems, running in different address spaces and often on different hosts, must be able to communicate with each other. JRMP permits program-level objects in different address spaces to invoke remote objects using the semantics of the Java programming language object model.
Complete information on the JRMP specification can be found at http://docs.oracle.com/javase/8/docs/technotes/guides/rmi .
7.2.4. Data Formats
In addition to the protocols that allow communication between components, this specification requires Jakarta EE platform support for a number of data formats. These formats provide the definition for data exchanged between components.
The following data formats must be supported:
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XML 1.0—The XML format can be used to construct documents, RPC messages, etc. The JAXP API provides support for processing XML format data. The Jakarta XML-based RPC API provides support for XML RPC messages, as well as a mapping between Java classes and XML.
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JSON—JSON is a language-neutral plain text format commonly used to transfer structured data between a server and web application. The Jakarta JSON Processing API provides support for the parsing, generation, transformation, and querying of JSON text. The Jakarta JSON Binding API provides support for mapping between JSON text and Java objects.
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HTML 4.01—This represents the minimum web browser standard document format. While all Jakarta EE APIs with the exception of Jakarta Server Faces are agnostic to the version of the browser document format, Jakarta EE web clients must be able to display HTML 4.01 documents.
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Image file formats—The Jakarta EE platform must support GIF, JPEG, and PNG images. Support for these formats is provided by the java.awt.image APIs (see the URL: http://docs.oracle.com/javase/8/docs/api/java/awt/image/package-summary.html ) and by Jakarta EE web clients.
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JAR files—JAR (Java Archive) files are the standard packaging format for Java technology-based application components, including the ejb-jar specialized format, the Web application archive (WAR) format, the Resource Adapter archive (RAR), and the Jakarta EE enterprise application archive (EAR) format. JAR is a platform-independent file format that permits many files to be aggregated into one file. This allows multiple Java components to be bundled into one JAR file and downloaded to a browser in a single HTTP transaction. JAR file formats are supported by the java.util.jar and java.util.zip packages. For complete information on the JAR specification, see http://docs.oracle.com/javase/8/docs/technotes/guides/jar .
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Class file format—The class file format is specified in the Java Virtual Machine specification. Each class file contains one Java programming language type—either a class or an interface—and consists of a stream of 8-bit bytes. For complete information on the class file format, see http://docs.oracle.com/javase/specs/ .
8. Application Assembly and Deployment
This chapter specifies Jakarta™ Enterprise Edition (Jakarta EE) requirements for assembling, packaging, and deploying a Jakarta EE application. The main goal of these requirements is to provide scalable and modular application assembly, and portable deployment of Jakarta EE applications into any Jakarta EE product.
Jakarta EE applications are composed of one or more Jakarta EE components and an optional Jakarta EE application deployment descriptor. The deployment descriptor, if present, lists the application’s components as module s. If the deployment descriptor is not present, the application’s modules are discovered using default naming rules. A Jakarta EE module represents the basic unit of composition of a Jakarta EE application. Jakarta EE modules consist of one or more Jakarta EE components and an optional module level deployment descriptor. The flexibility and extensibility of the Jakarta EE component model facilitates the packaging and deployment of Jakarta EE components as individual components, component libraries, or Jakarta EE applications.
A full Jakarta EE product must support all the facilities described in this chapter. A Jakarta EE profile may support only a subset of the Jakarta EE module types. Any requirements related to a module type not supported by a product based on a particular Jakarta EE profile should be understood to not apply to such a product.
Jakarta EE Deployment shows the composition model for Jakarta EE deployment units and includes the optional use of alternate deployment descriptors by the application package to preserve any digital signatures of the original Jakarta EE modules. An alternate deployment descriptor may also be provided external to the application package as described in Assembling a Jakarta EE Application.”
8.1. Application Development Life Cycle
The development life cycle of a Jakarta EE application begins with the creation of discrete Jakarta EE components. These components may then be packaged with a module level deployment descriptor to create a Jakarta EE module. Jakarta EE modules can be deployed as stand-alone units or can be assembled with a Jakarta EE application deployment descriptor and deployed as a Jakarta EE application.
Jakarta EE Application Life Cycle shows the life cycle of a Jakarta EE application.
8.1.1. Component Creation
The Jakarta Enterprise Beans, Jakarta Servlet, application client, and Jakarta Connector specifications include the XML Schema definition of the associated module level deployment descriptors and component packaging architecture required to produce Jakarta EE modules. (The application client specification is found in CHApter of this document.)
A Jakarta EE module is a collection of one or more Jakarta EE components (web, Jakarta Enterprise Beans, application client, or Jakarta Connector) with an optional module deployment descriptor of that type. Any number of components of the same container type can be packaged together with a single Jakarta EE deployment descriptor appropriate to that container type to produce a Jakarta EE module. Components of different container types may not be mixed in a single Jakarta EE module, except for the packaging of Jakarta Enterprise Beans components within a web module.
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A Jakarta EE module represents the basic unit of composition of a Jakarta EE application. In some cases a single Jakarta EE module (not necessarily packaged into a Jakarta EE application package) will contain an entire application. In other cases an application will be composed of multiple Jakarta EE modules.
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The deployment descriptor for a Jakarta EE module contains declarative data required to deploy the components in the module. The deployment descriptor for a Jakarta EE module also contains assembly instructions that describe how the components are composed into an application.
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Starting with version 5 of the Java EE, a web application module, an enterprise bean module, or an application client module need not contain a deployment descriptor. Instead, the deployment information may be specified by annotations present in the class files of the module.
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Starting with version 5 of the Java EE, a Jakarta EE enterprise application archive need not contain a deployment descriptor. Instead, the deployment information may be determined using default naming rules for embedded modules.
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An individual Jakarta EE module can be deployed as a stand-alone Jakarta EE module without an application level deployment descriptor and represents a valid Jakarta EE application.
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Jakarta EE modules may express dependencies on libraries as described below in Library Support.”
All Jakarta EE modules have a name. The name can be explicitly set in the deployment descriptor for the module. If not set, the name of the module is the pathname of the module in the ear file with any filename extension (.jar, .war, .rar) removed, but with any directory names included. The name of a module must be unique within an application. If and only if the name is not unique (e.g., because two names are identical after removing different filename extensions) the deployment tool may choose new unique names for any of the conflicting modules; module names that do not conflict must not be changed. The algorithm for choosing unique names in such a case is product specific. Applications that depend on the names of their modules must ensure that their module names are unique.
For example, an application with this structure:
myapp.ear inventory.jar ui.war
has a default application name of "myapp", and defines two modules with default names "inventory" and "ui".
An application with this structure:
bigapp.ear ejbs inventory.jar accounts.jar ui store.war admin.war
has a default application name of "bigapp", and defines four modules with default names "ejbs/inventory", "ejbs/accounts", "ui/store", and "ui/admin".
8.1.2. Application Assembly
A Jakarta EE application may consist of one or more Jakarta EE modules and one Jakarta EE application deployment descriptor. A Jakarta EE application is packaged using the Jakarta Archive (JAR) file format into a file with a .ear (Enterprise ARchive) filename extension. A minimal Jakarta EE application package will only contain Jakarta EE modules and, optionally, the application deployment descriptor. A Jakarta EE application package may also include libraries referenced by Jakarta EE modules (using the Class-Path mechanism described below in Library Support”), help files, and documentation to aid the deployer.
The deployment of a portable Jakarta EE application should not depend on any entities that may be contained in the package other than those defined by this specification. Deployment of a portable Jakarta EE application must be possible using only the application deployment descriptor, if any, and the Jakarta EE modules (and their dependent libraries) and descriptors listed in it.
The Jakarta EE application deployment descriptor represents the top level view of a Jakarta EE application’s contents. The Jakarta EE application deployment descriptor is specified by an XML schema or document type definition (see Jakarta EE Application XML Schema”).
In certain cases, a Jakarta EE application will need customization before it can be deployed into the enterprise. New Jakarta EE modules may be added to the application. Existing modules may be removed from the application. Some Jakarta EE modules may need custom content created, changed, or replaced. For example, an application consumer may need to use an HTML editor to add company graphics to a template login page that was provided with a Jakarta EE web application.
All Jakarta EE applications have a name. The name can be explicitly set in the application deployment descriptor. If not set, the name of the application is the base name of the ear file with any .ear extension removed and with any directory names removed. The name of an application must be unique in an application server instance. If an attempt is made to deploy an application with a name that conflicts with an already deployed application, the deployment tool may choose a new unique name for the application. The deployment tool may also allow a different name to be specified at deployment time. A deployment tool may use product-specific means to decide whether a deployment operation is a deployment of a new application, in which case the name must be unique, or a redeployment of an existing application, in which case the name may match the existing application.
Similarly, when a stand-alone module is deployed, the module name is used as the application name, and obeys the same rules as described above for application names. The module name can be explicitly set in the module deployment descriptor. If not set, the name of the module is the base name of the module file with any extension ( .war , .jar , .rar ) removed and with any directory names removed.
8.1.3. Deployment
During the deployment phase of an application’s life cycle, the application is installed on the Jakarta EE platform and then is configured and integrated into the existing infrastructure. Each Jakarta EE module listed in the application deployment descriptor (or discovered using the default rules described below) must be deployed according to the requirements of the specification for the respective Jakarta EE module type. Each module listed must be installed in the appropriate container type and the environment properties of each module must be set appropriately in the target container to reflect the values declared by the deployment descriptor element for each component.
Every resource reference should be bound to a resource of the required type.
Some resources have default mapping rules specified; see sections Default Data Source, Default JMS Connection Factory, and Default Concurrency Utilities Objects. By default, a product must map otherwise unmapped resources using these default rules. A product may include an option to disable or override these default mapping rules.
Once a resource reference is bound to a resource in the target operational environment, and deployment succeeds, that binding is not expected to change. A product may provide administrative operations that change the resource bindings that are used by applications. A product may notify applications of changes to their resource bindings using JNDI events, but this is not required.
If deployment succeeds, in addition to binding resource references as specified above, every resource definition (see section Resource Definition and Configuration) specified by the application or specified or overridden by the Deployer must be present in the target operational environment.
8.2. Library Support
The Jakarta EE provides several mechanisms for applications to use optional packages and shared libraries (hereafter referred to as libraries ). Libraries may be bundled with an application or may be installed separately for use by any application.
Jakarta EE products are required to support the use of bundled and installed libraries as specified in the Extension Mechanism Architecture and Optional Package Versioning specifications (available at http://docs.oracle.com/javase/8/docs/technotes/guides/extensions/ ) and the JAR File Specification (available at http://docs.oracle.com/javase/8/docs/technotes/guides/jar/jar.html ). Using this mechanism a Jakarta EE JAR file can reference utility classes or other shared classes or resources packaged in a separate .jar file or directory that is included in the same Jakarta EE application package, or that has been previously installed in the Jakarta EE containers.
8.2.1. Bundled Libraries
Libraries bundled with an application may be referenced in the following ways:
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A JAR format file (such as a .jar file, .war file, or .rar file) may reference a .jar file or directory by naming the referenced .jar file or directory in a Class-Path header in the referencing JAR file’s Manifest file. The referenced .jar file or directory is named using a URL relative to the URL of the referencing JAR file. The Manifest file is named META-INF/MANIFEST.MF in the JAR file. The Class-Path entry in the Manifest file is of the form
Class-Path: list-of-jar-files-or-directories-separated-by-spaces
(See the JAR File Specification for important details and limitations of the syntax of Class-Path headers.) The Jakarta EE deployment tools must process all such referenced files and directories when processing a Jakarta EE module. Any deployment descriptors in referenced .jar files must be ignored when processing the referencing .jar file. The deployment tool must install the .jar files and directories in a way that preserves the relative references between the files. Typically this is done by installing the .jar files into a directory hierarchy that matches the original application directory hierarchy. All referenced .jar files or directories must appear in the logical class path of the referencing JAR files at runtime.
Only JAR format files or directories containing class files or resources to be loaded directly by a standard class loader should be the target of a Class-Path reference; such files are always named with a .jar extension. Top level JAR files that are processed by a deployment tool should not contain Class-Path entries; such entries would, by definition, reference other files external to the deployment unit. A deployment tool is not required to process such external references.
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A .ear file may contain a directory that contains libraries packaged in JAR files. The library-directory element of the .ear file’s deployment descriptor contains the name of this directory. If a library-directory element isn’t specified, or if the .ear file does not contain a deployment descriptor, the directory named lib is used. An empty library-directory element may be used to specify that there is no library directory.
All files in this directory (but not subdirectories) with a .jar extension must be made available to all components packaged in the EAR file, including application clients. These libraries may reference other libraries, either bundled with the application or installed separately, using any of the techniques described herein.
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A web application may include libraries in the WEB-INF/lib directory. See the Jakarta Servlet specification for details. These libraries may reference other libraries, either bundled with the application or installed separately, using any of the techniques described herein.
8.2.2. Installed Libraries
Libraries that have been installed separately may be referenced in the following way:
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JAR format files of all types may contain an Extension-List attribute in their Manifest file, indicating a dependency on an installed library. The JAR File Specification defines the semantics of such attributes for use by applets; this specification requires support for such attributes for all component types and corresponding JAR format files. The deployment tool is required to check such dependency information and reject the deployment of any component for which the dependency can not be met. Portable applications should not assume that any installed libraries will be available to a component unless the component’s JAR format file, or one of the containing JAR format files, expresses a dependency on the library using the Extension-List and related attributes.
The referenced libraries must be made available to all components contained within the referencing file, including any components contained within other JAR format files within the referencing file. For example, if a .ear file references an installed library, the library must be made available to all components in all .war files, Jakarta Enterprise Beans .jar files, application .jar files, and resource adapter .rar files within the .ear file.
A Jakarta EE product is not required to support downloading of libraries (using the <extension>-Implementation-URL header) at deployment time or runtime. A Jakarta EE product is also not required to support more than a single version of an installed library at once. A Jakarta EE product is not required to limit access to installed libraries to only those for which the application has expressed a dependency; the application may be given access to more installed libraries than it has requested. In all of these cases, such support is highly recommended and may be required in a future version of this specification. In particular, we recommend that a Jakarta EE product support multiple versions of an installed library, and by default only allow applications to access the installed libraries for which they have expressed a dependency.
8.2.3. Library Conflicts
If an application includes a bundled version of a library, and the same library exists as an installed library, the instance of the library bundled with the application should be used in preference to any installed version of the library. This allows an application to bundle exactly the version of a library it requires without being influenced by any installed libraries. Note that if the library is also a required component of the Jakarta EE version on which the application is being deployed, this version may (and typically will) take precedence.
8.2.4. Library Resources
In addition to allowing access to referenced classes, as described above, any resources contained in the referenced JAR files must also be accessible using the Class and ClassLoader getResource methods, as allowed by the security permissions of the application. An application will typically have the security permissions required to access resources in any of the JAR files packaged with the application.
8.2.5. Dynamic Class Loading
Libraries that dynamically load classes must consider the class loading environment of a Jakarta EE application. Libraries will often be loaded by a class loader that is a parent class loader of the class loader that is used to load application classes and thus will not have direct visibility to classes of the application modules. A library that only needs to dynamically load classes provided by the library itself can safely use the Class method forName . However, libraries that need to dynamically load classes that have been provided as a part of the application need to use the context class loader to load the classes. Note that the context class loader may be different in each module of an application. Access to the context class loader requires RuntimePermission (“ getClassLoader”) , which is not normally granted to applications, but should be granted to libraries that need to dynamically load classes. Libraries can use a method such as the following to assert their privilege when accessing the context class loader. This technique will work in both Java SE and Jakarta EE.
public ClassLoader getContextClassLoader() {
return AccessController.doPrivileged(
new PrivilegedAction<ClassLoader>() {
public ClassLoader run() {
ClassLoader cl = null;
try {
cl = Thread.currentThread().
getContextClassLoader();
} catch (SecurityException ex) { }
return cl;
}
});
}
Libraries should then use the following technique to load classes.
ClassLoader cl = getContextClassLoader();
if (cl != null) {
try {
clazz = Class.forName(name, false, cl);
} catch (ClassNotFoundException ex) {
clazz = Class.forName(name);
}
} else
clazz = Class.forName(name);
8.2.6. Examples
The following example illustrates a simple use of the bundled library mechanism to reference a library of utility classes that are shared between enterprise beans in two separate ejb-jar files.
app1.ear: META-INF/application.xml ejb1.jar Class-Path: util.jar ejb2.jar Class-Path: util.jar util.jar
The next example illustrates a more complex use of the Class-Path mechanism. In this example the Developer has chosen to package the enterprise bean client view classes in a separate JAR file and reference that JAR file from the other JAR files that need those classes. Those classes are needed both by ejb2.jar , packaged in the same application as ejb1.jar , and by ejb3.jar and jakartaservlet1.jar , packaged in a different application. Those classes are also needed by ejb1.jar itself because they define the remote interface of the enterprise beans in ejb1.jar , and the developer has chosen the by reference model of making these classes available, as described in the Jakarta Enterprise Beans spec. The deployment descriptor for ejb1.jar names the client view JAR file in the ejb-client-jar element.
The Class-Path mechanism must be used by components in app3.ear to reference the client view JAR file that corresponds to the enterprise beans packaged in ejb1.jar of app2.ear . These enterprise beans are referenced by enterprise beans in ejb3.jar and by the Jakarta Servlets packaged in webapp.war .
app2.ear: META-INF/application.xml ejb1.jar Class-Path: ejb1_client.jar deployment descriptor contains: <ejb-client-jar>ejb1_client.jar</ejb-client-jar> ejb1_client.jar ejb2.jar Class-Path: ejb1_client.jar app3.ear: META-INF/application.xml ejb1_client.jar ejb3.jar Class-Path: ejb1_client.jar webapp.war Class-Path: ejb1_client.jar WEB-INF/web.xml WEB-INF/lib/jakartaservlet1.jar
The following example illustrates a simple use of the installed library mechanism to reference a library of utility classes that is installed separately.
app1.ear: META-INF/application.xml ejb1.jar : META-INF/MANIFEST.MF: Extension-List: util util-Extension-Name: com/example/util util-Specification-Version: 1.4 META-INF/ejb-jar.xml util.jar: META-INF/MANIFEST.MF: Extension-Name: com/example/util Specification-Title: example.com’s util package Specification-Version: 1.4 Specification-Vendor: example.com Implementation-Version: build96
8.3. Class Loading Requirements
The Jakarta EE specification purposely does not define the exact types and arrangements of class loaders that must be used by a Jakarta EE product. Instead, the specification defines requirements in terms of what classes must or must not be visible to components. A Jakarta EE product is free to use whatever class loaders it chooses to meet these requirements. Portable applications must not depend on the
types of class loaders used or the hierarchical arrangement of class loaders, if any. Portable applications must not depend on the order in which classes and resources are loaded. Applications should use the techniques described in Dynamic Class Loading” if they need to load classes dynamically.
In addition to the required classes specified below, a Jakarta EE product must provide a way to allow an application to access a class library installed in the application server, even if it has not expressed a dependency on that library. This supports the use of o