Question on Aries Extensions - JPA persistence injection etc

[Matt Madhavan <ma...@gmail.com>]

Hello,
I have found some references to Aries extensions like JPA annotations etc in
couple of places. For instance the IBM redbook talks about Blueprint-based
injection of persistence services:

I cannot find any information on this. Can some one point me to the right
source of documentations please?

Any information at this point will be helpful.

Thanks
Matt

Re: Question on Aries Extensions - JPA persistence injection etc

[Valentin Mahrwald <vm...@googlemail.com>]

Hi Matt,

a bit is mentioned in http://aries.apache.org/modules/jpaproject.html, which is under the general Documentation -> Programming Model link.


It's not particular verbose about injection in particular though :) Basically it comes in two flavours, for both the namespace to use would be
http://aries.apache.org/xmlns/jpa/v1.1.0.

a) Container managed JPA (injecting an EntityManager)

This looks something like

<bean class="PersistenceService">
  <jpa:context property="entityManager" unitname="pu" />
</bean>

for a persistence unit "pu" and a bean PersistenceService with a void setEntityManager(EntityManager em) method. Or for constructor
injection a la PersistenceService(EntityManager em):

<bean class="PersistenceService">
  <jpa:context index="0" unitname="pu" />
</bean>

There is also support for using a nested map element (from the standard Blueprint namespace) to specify properties for the persistence context.

b) Application managed JPA (injecting an EntityManagerFactory)

Similar to the above:

<bean class="PersistenceService">
  <jpa:unit property="entityManagerFactory" />
</bean>

for a PersistenceService bean with method setEntityManagerFactory(EntityManagerFactory). Constructor injection works as well.

By default in any of these cases transaction scope is assumed for the persistence unit. For extended persistence unit use a type="EXTENDED".


Injection by annotation on the other hand is currently not available in Aries as opposed to the feature pack that the redbook talks about.

Hope this helps,

Valentin


On 7 Apr 2011, at 19:38, Matt Madhavan wrote:

> Hello, 
> I have found some references to Aries extensions like JPA annotations etc in couple of places. For instance the IBM redbook talks about Blueprint-based injection of persistence services:
> 
> I cannot find any information on this. Can some one point me to the right source of documentations please? 
> 
> Any information at this point will be helpful.
> 
> Thanks
> Matt
>