WebSphere and TransactionRolledbackException Details

Question

Hello everyone,
we are currently using TopLink and WAS 5.1 to develop a "rich client" application with a Swing client. All database operations are performed on the server side within session beans using TopLink 9.0.4 and the WAS JTS transaction controller coming with TopLink.
And now comes the problem: When the transaction is committed, database operations performed by TopLink can fail because of SQLExceptions. How do I get these SQLExceptions back to the client? I have read several posts in this forum and WebSphere related newsgroups but didn't find a solution. I guess we are not the only ones using this kind of architecture and probably someone has solved this problem or found a work-around. Possibly by adjusting the transaction controller.
This problem is somewhat urgent, because depending on the cause of the exceptions, the client has to do different things to handle the exception (e.g. unique key constraints or duplicate key exceptions). This can only be realized when we get the cause of the transaction to roll back.
Any help is welcome!
Thomas

Answer 1

Okay, I think I need to clarify the problem here. All our business logic is implemented using stateless EJB session beans, which are called from the client. All database operations are performed within these session beans and the transactions are managed by the container (WebSphere). Since we are not responsible for transaction management, all transaction handling is done by the container, including the commit of the transaction and also the TopLink UnitOfWork. So the code looks a little bit like this.
public String doSomething() {
// get the session using the session manager
UnitOfWork uow = session.getActiveUnitOfWork();
// Create a new object, no INSERT happens here,
// so nothing goes wrong
uow.registerNewObject(...);
// Everything went fine, so we return OK
return "OK"
After we return from this method, the transaction is committed by the container and the SQL statements are executed. There we get e.g. a unique key constraint violation from the database. There is no way for the method to handle this exception. The only thing the client notices is, that the transaction commit failed and the transaction was rolled back. Nothing more, no detailed exception message explaining the cause. This is the normal behaviour with no exception handler installed and also with an exception handler installed and rethrowing the exception. We have tried both. We also thought about saving the exception message at some place for the client to retrieve it later on, but that is almost impossible. We are using stateless session beans, so there is no session to store the message in. Also we don't have the session context available in the exception handler. Even if we tried to return some kind of ResultCode object to the client, we can't change the object in the exception handler and we don't get the object to the client, since an exception occurs during the method execution (from the client's point of view).
I hope this helps to clarify the problem a little bit.
Thomas