Session session = getSession(dataSource, sessionFactory, Connection.TRANSACTION_SERIALIZABLE);
public Session getSession(DataSource dataSource, SessionFactory sessionFactory, int isolationLevel){
// Get connection from current dataSource and set new isolation
Connection connectionWithNewIsolation = dataSource.getConnection();
connectionWithNewIsolation.setTransactionIsolation(isolationLevel);
// Get session from current sessionFactory with the new isolation
Session session = sessionFactory.openSession(connectionWithNewIsolation);
// Hibernate 4.3
//SessionFactory.openStatelessSession(Connection connection)
// Hibernate 3.6
//SessionFactory.openSession(Connection connection)
//SessionFactory.openStatelessSession(Connection connection)
return session;
}