I have a client application (Swing) that uses Hibernate 2.1 for database access (SQL Server).

I'm using optimistic locking (w/ version numbers). I'm also using lazy loading to get rid of some performance bottlenecks when retrieving large resultsets.

Since my application always runs in a single thread, I keep the Hibernate Session, and only one Session, open throughout the application lifecycle. It is opened when the application starts, and closed when the application terminates. I am not closing the Session after transactions, etc.

The application maintains a single instance of each persistent object (more or less, some reports in the application do things a little differently).

I'm having a few problems with combining lazy loading and recovering from StaleObjectStateExceptions.

Two problems:

1) if I open the session before each transaction and close it after the transaction has completed, lazy loading stops working.

2) if I don't open and close the session before and after each transaction, I can not recover from StaleObjectStateObjections. I'm doing session.refresh(myBean) after the exception, but that does not update the optimistic locking version number of the entity the SessionImpl class keeps cached.

I've read about the ThreadLocal approach, long transactions (disconnect() and reconnect()), but these are not working either. The information I have been able to find to help me with this, is all geared towards web based development and I'm having a hard time figuring out how it all applies to my problem.

Anyone out there able to help me with this?

Thanks!

-TPP

So, basically you are working with stale data all the time. Learn how update() and lock() works.

Care to elaborate?

-TPP

http://www.hibernate.org/hib_docs/refer ... c-detached

http://www.hibernate.org/Documentation/ ... ctionScope

Getting Hibernate in Action is also not a bad idea, as always ;)

I've read all that and tried the different approaches already.

I still can not get recovery from stale data exception and lazy loading to work at the same time.

If I open/close sessions, lazy loading does not work, but I can recover from stale data exceptions. This is the piece I can't figure out.

Do I have to reload the "root" object before accessing the collections I'm trying to lazy load? These collections are accessed in separate application transactions (to use the term from the latter document) from loading the "root" objects.

-TPP

An object has to be associated with a connected Session if you want to load lazy properties.