Hibernate Transaction Manager not committing data changes - spring

Question

I'm using Hibernate 4 to write data to an H2 embedded in-memory database and there seems to be a problem with transactions. The application already uses Oracle and H2 has been added with a separate DataSource, SessionFactory, and TransactionManager. The original TransactionManager is marked as default and the H2 TransactionManager has the qualifier memTransactions
The following code - specifically the load function - correctly populates the memEvents variable at the end with the written data.
#Repository
#Transactional(transactionManager = "memTransactions")
public class EventMemDaoHibernate implements EventMemDao {
#Autowired
#Qualifier(value = "memSessionFactory")
private SessionFactory memSessionFactory;
#Override
public List<EventMem> getEvents() {
return memSessionFactory.getCurrentSession().createCriteria(EventMem.class).list();
}
#Override
public void load(List<Event> allEvents) {
Session session = memSessionFactory.getCurrentSession();
for (Event e : allEvents) {
EventMem memEvent = new EventMem(e);
session.save(memEvent);
}
List<EventMem> memEvents = getEvents(); // correct
}
}
However the following code produces an empty memEvents list
#Autowired
private EventMemDao eventMemDao;
List<Event> allEvents = eventDao.getAllEvents();
eventMemDao.load(allEvents); // calls the load function shown above
List<EventMem> memEvents = eventMemDao.getEvents(); // empty
I assume this is related to transaction management (e.g.: data is not auto-committed after the call to .save()). However when I tried explicitly beginning and committing a transaction within EventMemDaoHibernate#load, I receive this error:
nested transactions not supported
So, from what I can tell the TransactionManager is working.
My TransactionManager and related bean definitions are shown below.
<bean
id="memTransactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="memSessionFactory" />
<qualifier value="memTransactions"/>
</bean>
<bean id="hDataSource" class="org.h2.jdbcx.JdbcDataSource">
<property name="url" value="jdbc:h2:mem:db1;DB_CLOSE_DELAY=-1;INIT=RUNSCRIPT FROM 'classpath:scripts/init-h2.sql'" />
<property name="user" value="sa" />
<property name="password" value="" />
</bean>
<bean
id="memSessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="hDataSource" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.H2Dialect</prop>
</props>
</property>
</bean>

Answer 1

This was due to my configuration error (of course). I didn't fully grasp that the connection URL was evaluated every time a session was opened against H2 and that means init-h2.sql was executed repeatedly. init-h2.sql included a truncate followed by an insert so it was dropping and recreating data every time Hibernate opened a session.