From: Reza Rahman <reza_rahman_at_lycos.com>
Date: Thu, 2 Aug 2012 11:59:57 -0400

Looks good.

> -----Original Message-----
> From: Nigel Deakin [mailto:nigel.deakin_at_oracle.com]
> Sent: Thursday, August 02, 2012 10:47 AM
> To: jsr343-experts_at_jms-spec.java.net
> Subject: [jsr343-experts] Re: (JMS_SPEC-70) Define annotations for
injecting
> MessagingContext objects
>
> Back in June I made some updated proposals for a suitable scope for
injected
> JMSContext objects, and came up with a combined transaction/method scope
> proposal which I wrote up here:
> http://java.net/projects/jms-spec/pages/JMSContextScopeProposals (these
are
> "option 2" and "option 3")
>
> Essentially, this proposed that the injected JMSContext would have a
single
> scope which was a combination of transaction and method scope.
>
> This received support from this expert group, but I have since spent a lot
of time
> discussing this with the Java EE spec leads and others in Oracle and had
some
> strong feedback that this proposal was potentially confusing and needed
> improvement. After much discussion we have come up with a new proposal
> "option 4", which I have described here:
> http://java.net/projects/jms-spec/pages/JMSContextScopeProposalsv4p1
>
> Essentially, the proposal is that the scope of an injected JMSContext
object will
> depend on whether it is used in a transaction. Whereas Option 2 and Option
3
> proposed a single scope which was used irrespective of whether there was a
> transaction or not, this option proposes that the scope used depends on
> whether the injected JMSContext is used in a transaction or not.
>
> * If an injected JMSContext is used in a JTA transaction (both
bean-managed and
> container-managed), its scope will be
> that of the transaction. This means that:
> - The JMSContext object will be automatically created the first time
it is used
> within the transaction.
> - The JMSContext object will be automatically closed when the
transaction is
> committed.
> - If, within the same JTA transaction, different beans, or different
methods
> within the same bean, use an injected
> JMSContext which is injected using identical annotations then they
will all
> share the same JMSContext object.
> * If an injected JMSContext is used when there is no JTA transaction then
its
> scope will be the existing CDI scope
> @RequestScoped. This means that:
> - The JMSContext object will be created the first time it is used
within a
> request.
> - The JMSContext object will be closed when the request ends.
> - If, within the same request, different beans, or different methods
within the
> same bean, use an injected
> JMSContext which is injected using identical annotations then they
will all
> share the same JMSContext object.
>
> * If injected JMSContext is used both in a JTA transaction and outside a
JTA
> transaction then separate JMSContext
> objects will be used, with a separate JMSContext object being used for
each
> JTA transaction as described above.
>
> I have updated that long list of use cases to demonstrate how this scope
would
> work in practice. This is split over two wiki pages here:
> http://java.net/projects/jms-spec/pages/JMSContextScopeProposalsv4p2
> http://java.net/projects/jms-spec/pages/JMSContextScopeProposalsv4p3
>
> Please take a look and let me know if you have any questions or comments.
>
> I'm going to send a separate email proposing some changes to the
JMSContext
> API itself. Since those don't depend on the details of what scope we use
I'd like
> to keep that discussion separate.
>
> Thanks,
>
> Nigel
>
> P.S. If you're getting confused with all these different proposals, I've
assembled
> a list of links on this wiki page:
> http://java.net/projects/jms-spec/pages/JMSContextScopeUseCases
>