Class Link

java.lang.Object
jakarta.ws.rs.core.Link

public abstract class Link extends Object

Class representing hypermedia links. A hypermedia link may include additional parameters beyond its underlying URI. Parameters such as rel or type provide additional meta-data. Links in responses can be followed by creating an Invocation.Builder or a WebTarget.

The methods toString() and valueOf(java.lang.String) can be used to serialize and de-serialize a link into a link header (RFC 5988).

Since:
2.0
Author:
Marek Potociar, Santiago Pericas-Geertsen
See Also:
  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static interface 
    Builder class for hypermedia links.
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    Rel link param from RFC 5988.
    static final String
    Title link param from RFC 5988.
    static final String
    Type link param from RFC 5988.
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    fromLink(Link link)
    Create a new builder instance initialized from another link.
    fromMethod(Class<?> resource, String method)
    Convenience method to build a link from a resource.
    Convenience method to build a link from a path.
    fromResource(Class<?> resource)
    Convenience method to build a link from a resource.
    Create a new builder instance initialized from an existing URI represented as a string.
    fromUri(URI uri)
    Create a new builder instance initialized from an existing URI.
    Create a new builder instance initialized from a URI builder.
    abstract Map<String,String>
    Returns an immutable map that includes all the link parameters defined on this link.
    abstract String
    Returns the value associated with the link rel param, or null if this param is not specified.
    abstract List<String>
    Returns the value associated with the link rel param as a list of strings or the empty list if rel is not defined.
    abstract String
    Returns the value associated with the link title param, or null if this param is not specified.
    abstract String
    Returns the value associated with the link type param, or null if this param is not specified.
    abstract URI
    Returns the underlying URI associated with this link.
    abstract UriBuilder
    Convenience method that returns a UriBuilder initialized with this link's underlying URI.
    abstract String
    Returns a string representation as a link header (RFC 5988).
    static Link
    valueOf(String value)
    Simple parser to convert link header string representations into a link.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
  • Field Details

  • Constructor Details

    • Link

      public Link()
  • Method Details

    • getUri

      public abstract URI getUri()
      Returns the underlying URI associated with this link.
      Returns:
      underlying URI.
    • getUriBuilder

      public abstract UriBuilder getUriBuilder()
      Convenience method that returns a UriBuilder initialized with this link's underlying URI.
      Returns:
      UriBuilder initialized using underlying URI.
    • getRel

      public abstract String getRel()
      Returns the value associated with the link rel param, or null if this param is not specified.
      Returns:
      relation types as string or null.
    • getRels

      public abstract List<String> getRels()
      Returns the value associated with the link rel param as a list of strings or the empty list if rel is not defined.
      Returns:
      relation types as list of strings or empty list.
    • getTitle

      public abstract String getTitle()
      Returns the value associated with the link title param, or null if this param is not specified.
      Returns:
      value of title parameter or null.
    • getType

      public abstract String getType()
      Returns the value associated with the link type param, or null if this param is not specified.
      Returns:
      value of type parameter or null.
    • getParams

      public abstract Map<String,String> getParams()
      Returns an immutable map that includes all the link parameters defined on this link. If defined, this map will include entries for rel, title and type.
      Returns:
      immutable map of link parameters.
    • toString

      public abstract String toString()
      Returns a string representation as a link header (RFC 5988). All link params are serialized as link-param="value" where value is a quoted-string. For example, <http://foo.bar/employee/john>; title="employee"; rel="manager friend"
      Overrides:
      toString in class Object
      Returns:
      string link header representation for this link.
    • valueOf

      public static Link valueOf(String value)
      Simple parser to convert link header string representations into a link.
       link ::= '<' uri 'gt;' (';' link-param)*
       link-param ::= name '=' quoted-string
       
      See RFC 5988 for more information.
      Parameters:
      value - String representation.
      Returns:
      newly parsed link.
      Throws:
      IllegalArgumentException - if a syntax error is found.
      See Also:
    • fromUri

      public static Link.Builder fromUri(URI uri)
      Create a new builder instance initialized from an existing URI.
      Parameters:
      uri - a URI that will be used to initialize the builder.
      Returns:
      a new builder.
      Throws:
      IllegalArgumentException - if uri is null.
    • fromUri

      public static Link.Builder fromUri(String uri)
      Create a new builder instance initialized from an existing URI represented as a string.
      Parameters:
      uri - a URI that will be used to initialize the builder.
      Returns:
      a new builder.
      Throws:
      IllegalArgumentException - if uri is null.
    • fromUriBuilder

      public static Link.Builder fromUriBuilder(UriBuilder uriBuilder)
      Create a new builder instance initialized from a URI builder.
      Parameters:
      uriBuilder - instance of URI builder.
      Returns:
      a new builder.
    • fromLink

      public static Link.Builder fromLink(Link link)
      Create a new builder instance initialized from another link.
      Parameters:
      link - other link used for initialization.
      Returns:
      a new builder.
    • fromPath

      public static Link.Builder fromPath(String path)
      Convenience method to build a link from a path. Equivalent to fromUriBuilder(UriBuilder.fromPath(path)).
      Parameters:
      path - a URI path that will be used to initialize the Link, may contain URI template parameters.
      Returns:
      a new Link.Builder.
      Throws:
      IllegalArgumentException - if path is null.
    • fromResource

      public static Link.Builder fromResource(Class<?> resource)
      Convenience method to build a link from a resource. Equivalent to Link.fromUriBuilder({@link UriBuilder#fromResource UriBuilder.fromResource(resource)}). Note that the link URI passed to the Link.Builder instance returned by this method is relative. Should the link be built as absolute, a base URI has to be specified in the builder prior to building the new link instance. For example, on a server side a UriInfo.getBaseUri() may be typically used to define the base URI of a link created using this method.
      Parameters:
      resource - a root resource whose Path value will be used to initialize the builder.
      Returns:
      a new link builder instance.
      Throws:
      IllegalArgumentException - if resource is not annotated with Path or resource is null.
      See Also:
    • fromMethod

      public static Link.Builder fromMethod(Class<?> resource, String method)
      Convenience method to build a link from a resource. Equivalent to Link.fromUriBuilder({@link UriBuilder#fromMethod(Class, String) UriBuilder.fromMethod(resource, method)}). Note that the link URI passed to the Link.Builder instance returned by this method is relative. Should the link be built as absolute, a base URI has to be specified in the builder prior to building the new link instance. For example, on a server side a UriInfo.getBaseUri() may be typically used to define the base URI of a link created using this method.
      Parameters:
      resource - the resource containing the method.
      method - the name of the method whose Path value will be used to obtain the path to append.
      Returns:
      the updated Link.Builder.
      Throws:
      IllegalArgumentException - if resource or method is null, or there is more than or less than one variant of the method annotated with Path.
      See Also: