// BMT idiom with getCurrentSession()
try {
   UserTransaction tx = (UserTransaction)new InitialContext()
            .lookup("java:comp/UserTransaction");
   tx.begin();
   
   // Do some work on Session bound to transaction
   factory.getCurrentSession().load(...);
   factory.getCurrentSession().persist(...);
   tx.commit();
}
catch (RuntimeException e) {
   tx.rollback();
   throw e; // or display error message
}