[jms-dev] MicroProfile Reactive Messaging: Message Driven Beans Redux

[Gordon Hutchison <gordon_hutchison@xxxxxxxxxx>]

For those interested in JMS 3.0, I would
draw their attention to
https://github.com/eclipse/microprofile-reactive-messaging/blob/master/spec/src/main/asciidoc/architecture.asciidoc

Where an annotation based message driven
bean specification is forming.

To whet your appetite, it here is an
example: 

@Incoming( "myTopic" ) 
public CompletionStage<Void> processMessage(Message<IncomingMessage>
msg) {
  System.out.println("Got message " + msg.getPayload());
  return msg.ack();
}

Versus I recent JMSnext presentation
I saw from David Blevins and Richard Monson-Haefel (paraphrased  here)


@MessageDriven
@MaxSessions(3)
@MaxMessagesPerSession(1)
public class BuildTaskMessageListener {

   @Destination( value = "TASK_QUEUE"
)                   // this
could of course be @Destination( TASK_QUEUE )
   @DestinationType( Queue.class )
   @MessageType( ObjectMessage.class)
   public void process( Tazk t ) throw
JMS Exception {
        t.doSomething();
  
   }
}


Personally for JMSnext I would propose:

1 - discuss having seperate annotations
for each of {send-que, receive-que, send-topic, receive-topic} to enable
the first two lines to be one line. 
2 - I would explore if it is possible
to infer the @MessageType from the parameter to the annotated method.
but that is a seperate topic. :-)

Gordon

Gordon Hutchison
IBM Systems Middleware
Websphere Application Server Development
IBM Hursley Lab, UK.
gordon_hutchison@xxxxxxxxxx
Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number
741598. 
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6
3AU