[cdi-dev] JMS 2.1: Proposal to allow any CDI managed bean in a Java EE application to listen for JMS messages

[Nigel Deakin]

On 24/08/2015 17:30, Nigel Deakin wrote:
> Over in the JMS 2.1 expert group I've just published some proposals to allow any CDI managed bean in a Java EE
> application to listen for JMS messages. This would be implemented as a standard CDI portable extension and would become
> a mandatory part of a full Java EE 8 application server.
>
> I would welcome any comments from the CDI spec experts here. If you're interested in helping, please take a look at
> https://java.net/projects/jms-spec/pages/CDIBeansAsJMSListeners
> and send comments or questions to me or to the public users at jms-spec.java.net alias.

Thank you for the feedback so far, which has been very helpful. I've also received some very helpful comments from the 
JMS expert group and community

If you planned to make comments but haven't got round to doing so, your feedback would still be appreciated.

I've attempted to record all the comments made so far on a wiki page. This is at
https://java.net/projects/jms-spec/pages/CDIListenerBeanComments

Here's a summary of the comments so far:

* Is there a way to avoid the application having to inject and instantiate the listener bean?
   See https://java.net/projects/jms-spec/pages/CDIListenerBeanComments#Creating_listener_beans_automatically

* Is there a way for the queue, message selector etc to be specified at runtime rather than hardcoded as an annotation?
   See https://java.net/projects/jms-spec/pages/CDIListenerBeanComments#Runtime_customisation

* It might be desirable to allow JMS listener beans to listen to temporary queues and topics.
   See https://java.net/projects/jms-spec/pages/CDIListenerBeanComments#Listening_to_temporary_queues_and_topics

* It's important that my application deploys even if the JMS provider isn't fully available yet
   See https://java.net/projects/jms-spec/pages/CDIListenerBeanComments#Handling_failures

* What scopes are active when the callback method is invoked?
   See 
https://java.net/projects/jms-spec/pages/CDIListenerBeanComments#What_scopes_are_active_when_the_callback_method_is_invoked?

* I think we should leverage the existing CDI event/observer functionality instead of introducing a completely new 
delivery mechanism
   See https://java.net/projects/jms-spec/pages/CDIListenerBeanComments#Are_CDI_events_better?

Please feel free to make comments on those comments, or to raise new comments.

Nigel