OpenJPA has the ability to cache both.
LieGrue,
struy
----- Original Message -----
> From: Romain Manni-Bucau <rmannibu...@gmail.com>
> To: dev@openejb.apache.org
> Cc:
> Sent: Thursday, October 4, 2012 7:18 AM
> Subject: Re: Can jpa queries be cached?
>
> Hi,
>
> With a jta persistence unit you shouldnt manage these things.
>
> Then the cache of queries should be configured for sql queries. Jpa queries
> are not so costly.
>
> - Romain
> Le 4 oct. 2012 01:47, "David Jencks" <david_jen...@yahoo.com> a
> écrit :
>
>> I see that both geronimo and openejb have jta or non-tx jpa query wrappers
>> that close the entity manager after the query executes. This pretty
>> effectively prevents the query from being re-executed.
>>
>> Despite recalling having written the geronimo version, I can't remember
>> why this is necessary.
>>
>> We've found someone who is doing something like this:
>>
>> @Stateless
>> @ConcurrencyManagement(ConcurrencyManagementType.CONTAINER)
>> @TransactionManagement(TransactionManagementType.CONTAINER)
>> @TransactionAttribute(TransactionAttributeType.REQUIRED)
>> public class Foo implements FooLocal
>> {
>> @PersistenceContext(unitName="FooJpa", type =
>> PersistenceContextType.TRANSACTION) private EntityManager em;
>>
>> private Query findBars;
>>
>> @PostConstruct void postConstruct()
>> {
>> findBars = em.createNamedQuery("findBars");
>> }
>>
>> public Collection<Bar> getAllBars() {
>> return findBars.getResultList();
>> }
>> }
>>
>> The second time getAllBars() is called, the em is closed.
>>
>> There are some other errors in their code which might possibly be causing
>> this, but I think what is happening is that the postconstruct is executing
>> outside a jta transaction, so that the findBars query is a wrapped query
>> that closes itself after the query executes, even though it is executing in
>> a jta environment.
>>
>> Should our wrapper only close the em if it is executed (rather than
>> created) outside a jta tx?
>>
>> advice really appreciated :-)
>>
>> thanks
>> david jencks
>>
>>
>>
>
