Is it legal to inject a @Stateful into an MDB?

Question

@Stateful
public class InteruptBean implements Interrupt {
    ....
}

@MessageDriven(...)
public class EchoTrigger implements MessageListener {
    @EJB Interrupt interrupt;

    ....
}

Or better phrased: Can I use a stateful EJB to pass state around in an asynchronous Event Driven Architecture?

score 4 · Answer 1 · answered Jun 30 '11 at 04:58

4

Yes it does not make sense. Because stateful session beans are meant for processing multiple requests from same client so that they have client-actions oriented processing. In this case MDB will be beans clients. MDB supports single request model. A request comes to MDB (in form of message) and it is processed. So both types of beans don't match in processing model.

answered Jun 30 '11 at 04:58

ag112

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Stack overflow won't let me mark two answers as correct, but thanks! – Jonathan S. Fisher Jun 30 '11 at 15:00
MDB supports single request model in the same way as SLSB, but the bean instances can be pooled, so injecting an SFSB doesn't make sense to me. – Brett Kail Jun 30 '11 at 15:24

score 2 · Accepted Answer · answered Jun 30 '11 at 04:41

2

Yes, it's "legal", but it's nonsensical. MDBs instances are pooled like SLSBs. The MDB will become non-functional after the SFSB times out.

It might work to explicitly create the SFSB at some point, and then pass a reference to the SFSB in the messages being sent to drive the MDB.

answered Jun 30 '11 at 04:41

Brett Kail

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To get around this, I found this syntax: @Resource private MessageDrivenContext context; Interrupt interrupt = (Interrupt) context.lookup("ejb/myStateful"); – Jonathan S. Fisher Jun 30 '11 at 14:59

Is it legal to inject a @Stateful into an MDB?

2 Answers2

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