Re: [webbeans-dev] Producer fields on EJBs

Pete Muir wrote: > I thought through this some, and bounced ideas off Andy. > Gavin, I'm not sure that producer fields on SLSBs makes much sense > - SLSBs instance state is undefined I think (some EJB expert > correct if I'm wrong ;-). I think the spec should say that the > behaviour of producer fields on SLSBs is undefined. > Assuming the above, I would still argue for a getFieldValue SPI > that throws IllegalStateException if invoked on an SLSB reference - > and I think this removes the issue Ken has with a many-to-one > instances. UnsupportedOperationException perhaps? > I'm slipping this for the upcoming release as we are too far from > consensus. > On 6 Apr 2009, at 18:22, Pete Muir wrote: >> >> On 6 Apr 2009, at 18:00, Kenneth Saks wrote: >> >>> >>> On Apr 6, 2009, at 12:31 PM, Pete Muir wrote: >>> >>>> Carlo, Ken, Andrew, >>>> >>>> JSR-299 supports the notion of a producer field. By adding the >>>> annotation @Produces to a field, you make it into a bean, which >>>> can be used as the source of injections. The field can also be >>>> associated with a scope. When you first look up an instance of a >>>> bean, the field value is accessed, and stored in the context for >>>> it's lifetime. >>>> >>>> As we deal with EJB references, we can't directly access the >>>> field value (using reflection) so I think we should use the SPI >>>> here. >>>> >>>> I propose we add a method with this signature to the >>>> SessionObjectReference we previously created for the purpose of >>>> casting/removing EJBs https://svn.jboss.org/repos/webbeans/ri/trunk/spi/src/main/java/org/jboss... >>> >>> There isn't necessarily a one-to-one relationship between an ejb >>> reference and a bean instance. For stateless session beans, any >>> one of the bean instances can be used for any invocation. >>> >>> Can't this behavior be handled by the web beans interceptor? By >>> definition, each interceptor instance has the same life cycle as >>> its associated bean instance, and the bean instance is available >>> via the Interceptor InvocationContext. >> >> I did consider this, but not sure how to retrieve the result >> invocationContext.getTarget() at the time it is needed for >> accessing the producer field. We can't just store it from the >> construction point onwards (serializability) and I can't see a way >> to access it at some other point in the lifecycle - the only way >> to run an @AroundInvoke is to call a method, and in this case >> which method would you run, and how would you guarantee it has no >> side effects? >> >>> >>> >>>> >>>> /** >>>> * Retrieve the value of a (possibly private) field >>>> * >>>> * @param field >>>> * the field to retrieve the value of >>>> * @return the retrieved value >>>> * @throws IllegalArgumentException >>>> * if the field doesn't exist on this session object >>>> instance >>>> */ >>>> public Object getFieldValue(Field field); >>>> >>>> Any comments? >>>> >>>> >>>> On 29 Mar 2009, at 22:57, Pete Muir wrote: >>>> >>>>> Ok, I would think that some language in the spec to hint at >>>>> this might be good, as instances of session beans elsewhere in >>>>> the spec implies a EJB reference. >>>>> >>>>> On 29 Mar 2009, at 18:04, Gavin King wrote: >>>>> >>>>>> Yes, this is a good question - the 299 implementation would need >>>>>> direct integration with the EJB container for this. (Not the >>>>>> only >>>>>> place this is needed.) >>>>>> >>>>>> >>>>>> On Sat, Mar 28, 2009 at 7:18 PM, Pete Muir <pmuir(a)redhat.com&gt; >>>>>> wrote: >>>>>>> Hey >>>>>>> >>>>>>> Not quite sure how this is supposed to work as everywhere we >>>>>>> hold a >>>>>>> reference (proxy) to the EJB, and therefore don't have access >>>>>>> to the >>>>>>> instance and therefore can't get hold of the fields. Any >>>>>>> pointers? >>>>>>> >>>>>>> Thanks! >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> Pete Muir >>>>>>> http://www.seamframework.org >>>>>>> http://in.relation.to/Bloggers/Pete >>>>>>> >>>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> Gavin King >>>>>> gavin.king(a)gmail.com >>>>>> http://in.relation.to/Bloggers/Gavin >>>>>> http://hibernate.org >>>>>> http://seamframework.org >>>>> >>>>> -- >>>>> Pete Muir >>>>> http://www.seamframework.org >>>>> http://in.relation.to/Bloggers/Pete >>>>> >>>>> _______________________________________________ >>>>> webbeans-dev mailing list >>>>> webbeans-dev(a)lists.jboss.org >>>>> https://lists.jboss.org/mailman/listinfo/webbeans-dev >>>> >>>> -- >>>> Pete Muir >>>> http://www.seamframework.org >>>> http://in.relation.to/Bloggers/Pete >>>> >>> >>> _______________________________________________ >>> webbeans-dev mailing list >>> webbeans-dev(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/webbeans-dev >> >> -- >> Pete Muir >> http://www.seamframework.org >> http://in.relation.to/Bloggers/Pete >> >> _______________________________________________ >> webbeans-dev mailing list >> webbeans-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/webbeans-dev > -- > Pete Muir > http://www.seamframework.org > http://in.relation.to/Bloggers/Pete > _______________________________________________ > webbeans-dev mailing list > webbeans-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/webbeans-dev -- Andrew Lee Rubinger Sr. Software Engineer JBoss, a division of Red Hat, Inc. http://exitcondition.alrubinger.com _______________________________________________ webbeans-dev mailing list webbeans-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/webbeans-dev