First, you should use a much more solid session/transaction handling infrastructure, like Spring offers you. This way you can use the Same Session across multiple DAO calls and the transaction boundary is explicitly set by the @Transactional annotation.
If this is for a test project of yours, you can use a simple utility like this one:
protected <T> T doInTransaction(TransactionCallable<T> callable) {
T result = null;
Session session = null;
Transaction txn = null;
try {
session = sf.openSession();
txn = session.beginTransaction();
result = callable.execute(session);
txn.commit();
} catch (RuntimeException e) {
if ( txn != null && txn.isActive() ) txn.rollback();
throw e;
} finally {
if (session != null) {
session.close();
}
}
return result;
}
And you can call it like this:
final Long parentId = doInTransaction(new TransactionCallable<Long>() {
@Override
public Long execute(Session session) {
Parent parent = new Parent();
Child son = new Child("Bob");
Child daughter = new Child("Alice");
parent.addChild(son);
parent.addChild(daughter);
session.persist(parent);
session.flush();
return parent.getId();
}
});
Check this GitHub repository for more examples like this one.