users@jpa-spec.java.net

[jpa-spec users] Re: Integration with CDI

From: Craig Ringer <craig_at_postnewspapers.com.au>
Date: Thu, 14 Jul 2011 09:51:26 +0800

Linda,

I realize you're busy and juggling a lot of things, so don't worry about
letting my mail get lost in the noise. Thanks for taking the time to
reply now.

It sounds like it might be necessary to bash together a couple of
example apps to show why injection into entity listeners is necessary
(showing how problematic the BeanManager access hacks currently required
are), along with a more definite proposal for how this might work. I'll
see if I can interest anybody in collaborating on that.

Personally, I think injection into JPA entities themselves is a marginal
idea at best; if anything I think a warning should be emitted if @Inject
is found in an @Entity. It's entity listeners where I think injection
support and lifecycle annotations are vital.

I'll work on bashing out a demo and description. Time and other
committments permitting I might even be able to have a look at how hard
it'd be to retrofit support into EclipseLink as a proof of concept.

I'm glad to hear the DS mapping issue got some attention. It's one of
those interesting little holes in the spec that I'm always tripping
over, making Java EE 6 usability and productivity far from what it could
be. I keep a list here:

http://blog.ringerc.id.au/2011/07/java-ee-6-traps-pitfalls-and-warts-list.html



On 14/07/2011 3:51 AM, Linda DeMichiel wrote:
> Hi Craig,
>
> Thanks for the feedback. I do apologize for having let your previous
> email
> sent to me lapse. Unfortunately it got buried hundreds of emails deep
> in my
> inbox.
>
> Actually, one of the things I have been discussing behind the scenes is
> how we might support CDI injection into entity listeners. In the
> meantime,
> if you or Adam have a concrete proposal that you would like to make,
> that is of course welcome. As you may have noticed, however, the group
> as a whole is not currently supportive of injection into JPA entities.
> If that changes, it could also be considered further.
>
> With regard to the datasource mapping item you mention (as well as the
> GlassFish issue you filed) -- that has triggered some interesting
> internal discussion here. We think your point is valid, and I will add
> this item to the queue for consideration for JPA 2.1.
>
> regards,
>
> -Linda
>
>
> On 7/13/2011 1:57 AM, Craig Ringer wrote:
>> Dear Linda Demichiel,
>>
>> I contacted you a few weeks ago to find out about any plans the JPA
>> 2.1 spec team had about specifying integration with
>> CDI, because it's a real sore-point in development of EE 6 apps at
>> present.
>>
>> I thought I'd follow up and see what you thought, as I haven't heard
>> back from you or seen any further discussion on the
>> -experts mailing list after Adam Bien reposted my message to him on
>> that list.
>>
>> I'm really concerned that JPA 2.1 might come out without any kind of
>> CDI integration, and it's such a big usability
>> issue on any kind of DI-based app (ie: any standard Java EE 6 app
>> using EJB 3.1 or plain CDI) that it'd be a big shame.
>> If there's any way I can help with this I'd be happy to, though I
>> don't feel particularly well qualified when it comes
>> to the details.
>>
>> More recently I've noticed another interesting hiccup. According to
>> the Glassfish folks, JTA datasource names in
>> persistence.xml must be looked up only in the container global JNDI
>> context, not the component/module context. That
>> means datasources for persistence.xml cannot be mapped using a
>> web.xml resource-ref and a glassfish-web.xml or
>> jboss-web.xml resource-ref mapping. This seems like an ...
>> interesting ... quirk, given that resources are mapped in
>> almost all other contexts and _need_ to be mappable for
>> inter-container portability. Is there any chance JPA 2.1 could
>> specify that persistence contexts be initialized within module
>> context, applying any mappings defined for that context?
>>
>> --
>> Craig Ringer
>>
>> POST Newspapers
>> 276 Onslow Rd, Shenton Park
>> Ph: 08 9381 3088 Fax: 08 9388 2258
>> ABN: 50 008 917 717
>> http://www.postnewspapers.com.au/


POST Newspapers
276 Onslow Rd, Shenton Park
Ph: 08 9381 3088 Fax: 08 9388 2258
ABN: 50 008 917 717
http://www.postnewspapers.com.au/