Are they supported by Hibernate?

The questions is, if i have code liked this:

Transaction tx = null;
try {
tx = hibernateSession.beginTransaction();
Transaction nestedTx = hibernateSession.beginTransaction();
persistentObject.changeValue("newValue");
nestedTx.commit();

.... more business logic ....
tx.commit();
}
catch (Exception ex) {
if (tx != null) {
tx.rollback();
log.error(e, e);
}
}

Will the tx.rollback() roll the nestedTx back as well?

No.

Read http://www.hibernate.org/hib_docs/reference/html/transactions.html

ok, thanx for the quick answer!

kind regards,

torsten