JPA + JMS + JTA transactions

[jimpo]

I have not found clear answers for this, maybe because JPA & JMS are too short words to search for in this forum

Say I have a method which does some updates to db using JPA and sends some messages using JMS. I want the method to execute transactionally. For this I need to use JTA, Spring's own transaction management handling is not enough (correct?).

How should I configure the different transactionManagers etc. to achieve this?

I am using Spring 2.0.x (although upgrading to 2.5 might be an option in case it is critical).

[Marten Deinum]

Spring's own transaction management handling is not enough (correct?).

Spring doesn't really do transaction management it delegates to underlying transaction managers. There is also one for jta JTATransactionManager. You need however a container which supports that or configure a standalone JTA implementation like JOTM.

[jimpo]

Originally Posted by mdeinum

Spring doesn't really do transaction management it delegates to underlying transaction managers. There is also one for jta JTATransactionManager. You need however a container which supports that or configure a standalone JTA implementation like JOTM.

Yep, that's what I fgured. What I am unsure of is how to configure the JPA, JTA and JMS related settings so that all participate in the JTA transaction nicely.

[Marten Deinum]

Configure them as you normally would. The only difference that instead of a JPATransactionManager you configure a JtaTransactionManager thats it... No more no less...

[jimpo]

I still don't quite get it. How do I configure my JPA entityManager (persistenceManager, or some other bean) to be aware of the JTA transactionManager?

When I use plain JPA (without JTA) my JPA transactionManager and JPA entity manager are connected by the transactionManager config:

    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
        <property name="jpaDialect" ref="jpaDialect" />
    </bean>

If I use jtaTransactionManager instead, this approach is of course no longer possible. How do I create the link between jtaTransactionManager and JPA entityManagerFactory (or some other JPA bean) so that JPA becomes aware of the JTA transactions?

[Marten Deinum]

You don't have to. You only have to make sure that all of your DataSources are XA capable.

[jimpo]

Originally Posted by mdeinum

You don't have to. You only have to make sure that all of your DataSources are XA capable.

So, some kind of magic happens behind the scenes? In which class: JtaTransactionManager, LocalContainerEntityManagerFactoryBean, ...?

Is this documented somewhere, in Spring HTML documentation, or in Javadocs? Or do I need to look at the source code for this kind of information?

I have not found much documentation on this, but I found one example on http://erich.soomsam.net/2007/04/. I don't fully understand all the code on that page (which is partly the reason I created this thread).

Here, there seems to be lots of configuration for connecting JPA and JTA, such as

    <!-- configure Hibernate to participate in JTA transactions using the JOTM transaction manager and
         specify further Hibernate specific configuration properties -->
    <property name="jpaPropertyMap">
      <map>
        <entry key="hibernate.transaction.manager_lookup_class"
               value="org.hibernate.transaction.JOTMTransactionManagerLookup"/>
        <entry key="hibernate.transaction.flush_before_completion"
               value="true"/>
        <entry key="hibernate.transaction.auto_close_session"
               value="true"/>
        <entry key="hibernate.current_session_context_class"
               value="jta"/>
        <entry key="hibernate.connection.release_mode"
               value="auto"/>                            
      </map>
    </property>

Isn't this necessary, then?

Appreciate all the comments, thanks.

[dejanp]

It could work with Hibernate, but if you want to do it "by the book" you would have to define the jtadatasource in persistence.xml.

[jimpo]

Originally Posted by dejanp

It could work with Hibernate, but if you want to do it "by the book" you would have to define the jtadatasource in persistence.xml.

Trying to gather up all the pieces... So, for my JPA persistence to work correctly with JTA transaction manager, I need to

1. use transaction-type="JTA" in persistence.xml
2. define a JTA transaction manager
3. use XA capable dataSources

That's it? I don't configure the link between JPA (entityManagers etc) and JTA in any way? Isn't there any documentation on this?

What's with all the extra configuration in http://erich.soomsam.net/2007/04/ ? Why doesn't he just do the 3 points from the list above?

[Marten Deinum]

The link here is the datasource, you have to make sure that you use the same datasource. For JTA is doesn´t matter what type of transactional resource it is, as long as it it XA capable, which is what you want how else would one integrate JMS and JDBC and ... if you need to make all the specific implementations aware of the JTATransaction.....

Why he does the extra configuration, I have no idea, he could wire them up.

I registered a JIRA issue and placed a request for documentation, this issue seems to arise more and more on the forums. Would be nice if we had some reference to point to.