Hi,
I do not think it is a good architecture to use a synchronous component (the
session bean) to access information that can only be obtained asynchronously. I
would suggest two approaches :
- make your client both an EJB client and a JMS client : the client invokes the
session bean to request the information from the JMS source and subscribe to the
corresponding Topic.
- if you don't want your client use JMS, let it poll a session bean to get the
result: of course the client initiates the request the same way as above; your JMS
source sends the info to a Message-driven Bean which will store it in an entity
bean; the polling method of your session bean will access the entity bean to check
if the data has arrived ...
Best Regards,
Fran�ois
> Bill Leonard wrote:
> >
> > I have a client that sends a synchronous request to my session bean and
> > expects the response to be sent synchronously. In order to fulfill the
> > request, the session bean talks to a component that uses JMS. Therefore,
> > the session bean publishes the request to the JMS-based component. Now, the
> > response from the JMS-based component is received only by subscribing to a
> > topic. In order for my session bean to return the response to the client in
> > the same thread (synchronously), it has to do one of the following:
> >
> > 1) the session bean can poll the destination using the
> > MessageConsumer.receive()methods.
> > 2) block on some event (??); Its MessageListener code would then receive the
> > published response (in a thread started by the JMS provider). It would then
> > signal the event on the session_bean. The session bean would become
> > unblocked and return the response to the client.
> >
> > I know (1) can be done. Is (2) possible?
> >
> > Also, I first thought that Message Driven Beans might be helpful but, after
> > reading about them, I see that in the above scenario, I'm still faced with
> > trying to get a session bean to act synchronously. If I used an MDB instead
> > of a session bean, the client would then have to communicate with the MDB
> > using publish/subscribe (and I wanted the client to communicate
> > synchronously)
--
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Fran�ois EXERTIER Evidian (Groupe Bull)
1, rue de Provence, BP 208, 38432 Echirolles cedex, FRANCE
mailto:[EMAIL PROTECTED]
http://www.evidian.com/jonas http://www.objectweb.org/jonas
Tel: +33 (0)4 76 29 71 51 - Fax: +33 (0)4 76 29 77 30
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