I would like to ask some questions about session and transactions in Hibernate.

I have a simple web application that uses Hibernate 3.1 and Tomcat 5.0 and an hsqldb database.
In my hibernate.cfg.xml I have added the following lines:

<property name="connection.datasource">java:comp/env/jdbc/TestDB</property>
<property name="transaction.manager_lookup_class">
org.hibernate.transaction.JOTMTransactionManagerLookup</property>
<property name="transaction.factory_class">
org.hibernate.transaction.JTATransactionFactory</property>


Since I added the JTA does this mean that my JOTMTransaction manager will take care of the transactions with the database?
Or in order to do that I have to use Session Beans and a J2EE application server that will offer me managed transactions? Basically I cannot clearly
understand what JTA will offer me if I do not use an application server such as JBOSS that offers managed transactions.

What brought me in this questions is that I had a simple getSomething() method:

Session session = HibernateUtil.getSession();
session.beginTransaction();
List result = session.createQuery("from Event").list();
session.getTransaction().commit();


that worked fine and when I added the JTA code the method works if I remove the session.beginTransaction(); and the session.getTransaction().commit();

Any explanations? Thanking you in advance...
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