I'm using Spring 2.5 with my custom class that implements MessageListener. If a JmsException is thrown in my onMessage( ) method, what happens to the state of the queue?
Is the message considered "delivered" b开发者_运维百科y the queue the moment onMessage is called? Or does the JmsException trigger some kind of rollback and the message is re-entered on the queue?
Thanks in advance!
From the JMS 1.1 spec...
4.5.2 Asynchronous Delivery
A client can register an object that implements the JMS MessageListener interface with a MessageConsumer. As messages arrive for the consumer, the provider delivers them by calling the listener’s onMessage method.
It is possible for a listener to throw a RuntimeException; however, this is considered a client programming error. Well-behaved listeners should catch such exceptions and attempt to divert messages causing them to some form of application-specific ‘unprocessable message’ destination.
The result of a listener throwing a RuntimeException depends on the session’s acknowledgment mode.
- AUTO_ACKNOWLEDGE or DUPS_OK_ACKNOWLEDGE - the message will be immediately redelivered. The number of times a JMS provider will redeliver the same message before giving up is provider-dependent. The JMSRedelivered message header field will be set for a message redelivered under these circumstances.
- CLIENT_ACKNOWLEDGE - the next message for the listener is delivered. If a client wishes to have the previous unacknowledged message redelivered, it must manually recover the session.
- Transacted Session - the next message for the listener is delivered. The client can either commit or roll back the session (in other words, a RuntimeException does not automatically rollback the session).
JMS providers should flag clients with message listeners that are throwing RuntimeExceptions as possibly malfunctioning.
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