Toplink and headstart

Question

Hello,
We are using headstart framework in 10g database and we have a web application that uses Toplink for O-R mapping.
We open QMS transaction in postAcquireUnitOfWork and close it in preCommitUnitOfWork.
But if there is and exception raised in an sql or plsql that is executed within the UnitOfWork, the QMS transaction stays opened in the session.
So the next client can get the "dirty" session with the opened QMS transaction inside.
It looks like before executing any statement inside a session, Toplink does commit, and this raises the exception:
Internal Exception: java.sql.SQLException: ORA-02091: transaction rolled back
ORA-02290: check constraint (HST9I.QMS_NEED_TO_CLOSE_TRANSACTION) violated Error Code: 2091 because the QMS transaction stayed opened.
Why does the Toplink session tries to execute commit before executing the first statement?
Is there any possibility to execute abort transaction from the toplink framework, if the UnitOfWork statements fail ?
Has anybody come up with a work around ?
Should we try to abort the QMS transaction in sessionListener.postAcquireClientSession (or a rollback) ?
Thanks
Kate

Answer 1

I've used Axis with Toplink a bit, but I'm not aware of an easy solution for a Toplink merge to be handled automatically by the Axis serialization engine.
In my application, I have an API layer for all biz/persistence logic. I have been careful to keep parameters to these APIs limited to simple types and arrays of simple types. It works fine for local calls, and it allows easy mapping between WSDL definitions and SOAP calls for remote access to my biz layer.
All adding/editing/deleting is performed via a parameterized API call. This fits well with the SOAP paradigm.
As for viewing data, I have thin objects that wrap my Toplink objects which I return as values.
Obviously, if your application isn't structured with an API layer, this may not be helpful.
If anyone has done something with Axis/Toplink beyond this, I'd be interested in learning about it.
Nate