How to use JTA support in Tomcat 6 for Hibernate?

Question

They recommend using JTA transaction support in Java EE environment.

But how to configure JTA in Tomcat6 so that Hibernate Session could use it ?

Starting with version 3.0.1, Hibernate added the SessionFactory.getCurrentSession() method. Initially, this assumed usage of JTA transactions, where the JTA transaction defined both the scope and context of a current session. Given the maturity of the numerous stand-alone JTA TransactionManager implementations, most, if not all, applications should be using JTA transaction management, whether or not they are deployed into a J2EE container. Based on that, the JTA-based contextual sessions are all you need to use.

^{(Hibernate Reference Documentation | Architecture. Contextual Sessions)}

Tradelast

Ok, I need a JNDI configured SessionFactory. Now when I'm able to get a SessionFactory thru lookup I need to configure JTA. My home classes use getCurrentSession() and as I can read in documentation this works only in JTA configured environment. Besides, as I already mentioned, virtually everyone recommends using JTA in JEE environment. – Tradelast

Don't use JTA just because someone told you that you need it. JTA is very complex, and unnecessary in 99% of situations. Hibernate/JPA will work just fine without it. – Doradorado

Ok, I need a JNDI configured SessionFactory. Why? – Wendall

@Pascal Thivent Because Hibernate developers in their documentation recommend doing so. – Tradelast

@Tradelast This is something I tend to use with a fully Java EE compliant server but, to be honest, I've never been able to find a good justification (the only one is when you run Hibernate as a JMX service). So I may be missing something but having the SessionFactory bound to a static (and final) variable in an HibernateUtil class is ok for me (and this is the recommended approach in Hibernate in Action for a servlet container). – Wendall

Answer 1

If you want JTA support in Tomcat you'll need to use a standalone transaction manager like Atomikos, JOTM, Bitronix, SimpleJTA, JBossTS or GeronimoTM/Jencks. But honestly, if you're not going to handle transactions across multiple resources, then you can live without JTA (and if you really need JTA, use a full blown application server).

Wendall

Atomikos was my choice, nicely integrated with Hibernate 5. – Beveridge

Answer 2

If you just want to use SessionFactory.getCurrentSession() you can just add the following two lines to your hibernate.cfg.xml:

<property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
<property name="hibernate.current_session_context_class">thread</property>

This will give you a unique Session for each thread. As a servlet request is always handled within one thread (given that your code doesn't spawn new ones), the Session will live for the whole request.

Don't forget to use a filter to close the Session after the request!

Mestizo

Be aware of the fact, that these parameters are obsoleted in Hibernate 5. For further information please check the migration guide. Example code from our project: hibernateProperties.setProperty("hibernate.transaction.jta.platform", "com.atomikos.icatch.jta.hibernate4.AtomikosPlatform"); hibernateProperties.setProperty("hibernate.transaction.coordinator_class", "jta"); – Beveridge