DeliveryMode (Jakarta EE Platform API)

```
public interface DeliveryMode
```
The delivery modes supported by the Jakarta Messaging API are PERSISTENT and NON_PERSISTENT.
A client marks a message as persistent if it feels that the application will have problems if the message is lost in transit. A client marks a message as non-persistent if an occasional lost message is tolerable. Clients use delivery mode to tell a Jakarta Messaging provider how to balance message transport reliability with throughput.
Delivery mode covers only the transport of the message to its destination. Retention of a message at the destination until its receipt is acknowledged is not guaranteed by a PERSISTENT delivery mode. Clients should assume that message retention policies are set administratively. Message retention policy governs the reliability of message delivery from destination to message consumer. For example, if a client's message storage space is exhausted, some messages may be dropped in accordance with a site-specific message retention policy.
A message is guaranteed to be delivered once and only once by a Jakarta Messaging provider if the delivery mode of the message is PERSISTENT and if the destination has a sufficient message retention policy.

Since:

JMS 1.0

Version:

Jakarta Messaging 2.0

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`NON_PERSISTENT`	This is the lowest-overhead delivery mode because it does not require that the message be logged to stable storage.
`static int`	`PERSISTENT`	This delivery mode instructs the Jakarta Messaging provider to log the message to stable storage as part of the client's send operation.

- Field Detail
  - NON_PERSISTENT
```
static final int NON_PERSISTENT
```
    This is the lowest-overhead delivery mode because it does not require that the message be logged to stable storage. The level of Jakarta Messaging provider failure that causes a NON_PERSISTENT message to be lost is not defined.
    A Jakarta Messaging provider must deliver a NON_PERSISTENT message with an at-most-once guarantee. This means that it may lose the message, but it must not deliver it twice.
    
    See Also:
    
    Constant Field Values
  - PERSISTENT
```
static final int PERSISTENT
```
    This delivery mode instructs the Jakarta Messaging provider to log the message to stable storage as part of the client's send operation. Only a hard media failure should cause a PERSISTENT message to be lost.
    
    See Also:
    
    Constant Field Values