Saving the same object in two sessions?

Melk · **Joined:** Sun Oct 12, 2003 6:33 pm **Posts:** 7

I have the following problem, in my application from time to time I retrieve objects from one (local) database and store them in another (remote) database.

Thus I have created two session objects, localSession and remoteSession, and proceeded the following way:

String query = ... // some query
List matches = localSession.find( query );
for ( Iterator it = matches.iterator(); it.hasNext(); )
{
Object match = it.next();
remoteSession.save( match );
localSession.delete( object );
}

However it seems two objects cannot be shared by the same session, or at least two collections referenced by the same object? If this is true, what would be a correct approach to this problem?

Thank you very much.

Melk

emmanuel · **Posted:** Wed Oct 22, 2003 4:34 am

Melk wrote:

However it seems two objects cannot be shared by the same session

Correct

Melk wrote:

If this is true, what would be a correct approach to this problem?

A object can be evicted from a session (session.evict(Object).

Code:

String query = ... // some query
List matches = localSession.find( query );
Object match;
for ( Iterator it = matches.iterator(); it.hasNext(); ) {
  match = it.next();
  localSession.evict(match);
  remoteSession.save(match);
  remoteSession.evict(match);
  localSession.delete(match);
} 

But this isn't efficient (particularly if match has lazy collections).
The other way is to copy the object.

You may also have a look at the replicate() method of Hibernate 2.1 but I don't know it's behavior.