The thing is that the CDI specification *requires* us to load the entity
classes, there is simply no way around it. Because we have to fire a
ProcessAnnotatedType<T> for the entity class (with T being the entity
class) there is no way to fire this event without loading the entity
class. Any CDI implementation will run into this, it is not specific to
Wildfly.
The only way to get around this is basically making sure that entities
are not made into CDI beans, so vetoing them as Jozef said, or packing
them into their own JAR, neither of which is a good solution.
Basically the JPA spec is broken, it can't deal with both CDI and class
transformation, and we need to hack around it somehow.
Stuart
Steve Ebersole wrote:
So you'd like JPA providers to read the JPA spec in a special
"WildFly
light" wrt these quoted sections? Put aside your understanding that
WildFly suffers from this particular problem and point out the JPA spec
passages that say I need to delay using that BeanManager. In fact, I'd
argue the wording implies that the BeanManager should be usable
immediately upon being passed to the JPA provider.
On the flip side, is it possible that other containers might *only*
make the BeanManager available during bootstrap?
As for WildFly+Hibernate, I have already provided hooks to make sure
this can be done properly (albeit in non-spec way) as outlined in
earlier response.
On Mon 10 Jun 2013 04:54:22 PM CDT, Jason Greene wrote:
> Right but my point is if the entities aren't instantiated, there is nothing for
the listener to listen for, and it can be delayed up until that point in the deployment
process.
>
> It seems that the only hard ordering, is that the bean manager be created on top of
PersistenceUnitInfo.getClassLoader().
>
> On Jun 10, 2013, at 4:41 PM, Steve Ebersole<steve(a)hibernate.org> wrote:
>
>> We are talking about entity listeners, not entities. Entities can be annotated
with callback methods as well, but those are not supported (by spec) for CDI injection.
>>
>> BTW, for those maybe not familiar... The relevant sections in the JPA spec are:
>>
>> 9.1 Java EE Deployment. In this section, it discusses the expectations of the
container. In the part that discusses the call to createContainerEntityManagerFactory
(aka, bootstrapping an EntityManagerFactory) it says:
>>
>> <quote>
>> If CDI is enabled, a BeanManager instance must be made available by the
container. The
>> container is responsible for passing this BeanManager instance via the map that
is passed as
>> an argument to the createContainerEntityManagerFactory call. The map key
>> used must be the standard property name javax.persistence.bean.manager.
>> </quote>
>>
>> And then, 3.5.1 Entity Listeners, as partially quote by Scott earlier.
>>
>>
>> On Mon 10 Jun 2013 03:46:01 PM CDT, Jason Greene wrote:
>>> I guess the point I am still not clear on is exactly when the entities are
instantiated. My understanding is that the earliest a user can cause a JPA impl load them
is inside a PostConstruct method. That is unless JPA providers load instances for some
kind of caching purposes?
>>>
>>> On Jun 10, 2013, at 12:25 PM, Steve Ebersole<steve(a)hibernate.org>
wrote:
>>>
>>>> As Scott stated, Hibernate is doing the CDI calls as part of the
>>>> EntityManagerFactory bootstrap (however that translates to WildFly
>>>> deployment phases...). There is a difficulty with delaying these CDI
>>>> calls. Getting around that would require either:
>>>> 1) a 2-phase bootstrap process for the EntityManagerFactory. Even
>>>> though that proposal was not accepted into the JPA spec, I went ahead
>>>> and broke out Hibernate's bootstrapping into a 2-phase process, so
>>>> WildFly (via jipijapa) could leverage that.
>>>> 2) Creating proxies of the listeners that delegate to the real listeners
>>>> and perform the init on first call. Ugh. Proxies calling proxies
>>>> calling proxies... not a recipe for great performance. Not to mention
>>>> don't call me to debug through that mess
>>>>
>>>> There is a third option. How entity listeners are built is hidden
>>>> behind an interface (called ListenerFactory oddly enough). I can expose
>>>> that as an integration point for WildFly to be able to plug in whatever
>>>> "delayed init" scheme it deems appropriate. The only reason
I'd suggest
>>>> this is if y'all feel strongly about option 2 above (I'm not
comfortable
>>>> implementing that in the Hibernate code base). But my vote would be for
>>>> the first option.
>>>>
>>>> I am open to other suggestions.
>>>>
>>>>
>>>> On 06/10/2013 02:10 AM, Jozef Hartinger wrote:
>>>>> Weld can be started before a JPA impl without a risk of suppressing
>>>>> ClassFileTransformers under condition that all entities are
annotated
>>>>> with @Vetoed. We could document that as a requirement.
>>>>>
>>>>> On 06/07/2013 06:20 PM, Scott Marlow wrote:
>>>>>> For application deployments that use ClassFileTransformer to
>>>>>> enhance/rewrite entity classes, we start the persistence unit
service
>>>>>> (PersistenceProvider.createContainerEntityManagerFactory())
during the
>>>>>> Phase.FIRST_MODULE_USE (before any application classes have been
loaded).
>>>>>>
>>>>>> For application deployments that have an explicit CDI Bean
Manager,
>>>>>> there is a beans.xml that means the ClassFileTransformer will not
work,
>>>>>> since the CDI Bean Manager will scan all of the application
classes
>>>>>> (loading them), before the persistence unit service is started
(so that
>>>>>> the persistence provider can use CDI in entity listeners).
>>>>>>
>>>>>> The same is also true for implicit CDI Bean manager support [1],
expect
>>>>>> all application deployments that contain an ejb3 module, will be
wired
>>>>>> for CDI (meaning JPA ClassFileTransformer support will work even
less).
>>>>>>
>>>>>> I raised this on the JPA 2.1 EG [2] in response to an earlier
>>>>>> discussion, about switching to a two phase approach to address
problems
>>>>>> like this (didn't discuss CDI implicit support then but am
raising that
>>>>>> now).
>>>>>>
>>>>>> [3] talks about why we don't create the CDI bean managers
before the
>>>>>> Install phase (would cause all application classes to be read
which
>>>>>> breaks JPA ClassFileTransformer use).
>>>>>>
>>>>>> [4] is for adding implicit CDI support but is blocked currently
by [5].
>>>>>>
>>>>>> We can add persistence unit flags
(jboss.as.jpa.classtransformer=false)
>>>>>> for disabling JPA ClassFileTransformer support as a workaround
but that
>>>>>> doesn't help enough since many deployments will have implicit
CDI
>>>>>> support enabled (since they contain EJB modules). We could add a
way to
>>>>>> disable implicit CDI support as another workaround for
deployments that
>>>>>> want to use ClassFileTransformer.
>>>>>>
>>>>>> I'm not yet seeing a proper fix for this. Anyone else?
>>>>>>
>>>>>> Scott
>>>>>>
>>>>>> [1]
http://docs.jboss.org/cdi/spec/1.1/cdi-spec.html#bean_archive
>>>>>> [2]
>>>>>>
https://java.net/projects/jpa-spec/lists/jsr338-experts/archive/2013-06/m...
>>>>>> [3]
https://issues.jboss.org/browse/WFLY-1322
>>>>>> [4]
https://issues.jboss.org/browse/WFLY-476
>>>>>> [5]
https://issues.jboss.org/browse/WFLY-1463
>>>>>> _______________________________________________
>>>>>> wildfly-dev mailing list
>>>>>> wildfly-dev(a)lists.jboss.org
>>>>>>
https://lists.jboss.org/mailman/listinfo/wildfly-dev
>>>>> _______________________________________________
>>>>> wildfly-dev mailing list
>>>>> wildfly-dev(a)lists.jboss.org
>>>>>
https://lists.jboss.org/mailman/listinfo/wildfly-dev
>>>> _______________________________________________
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>>>>
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>>> --
>>> Jason T. Greene
>>> WildFly Lead / JBoss EAP Platform Architect
>>> JBoss, a division of Red Hat
>>>
> --
> Jason T. Greene
> WildFly Lead / JBoss EAP Platform Architect
> JBoss, a division of Red Hat
>
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