Catching and Handling ReportServiceException

Happy

Hi guys,
I am looking for ideas on how to catch and handle ReportServiceExceptions that occur with situations like this:

Required parameter not set
Can not connect to database
etc etc.

Exceptions that occur in my java event handlers are caught and managed by setting a global persistent "MESSAGES" variable and dropping the bound data to prevent database queries, however I can't quite figure out how to handle these ReportServiceException errors that pop up in the BIRT-Viewer from time to time.

The reason why I wish to trap them is to not expose the exceptions to the end-user. I wish to log the exception and display a meaningful error message using the method in the previous paragraph.

If the user digs into the stack trace which is currently displayed on their screen in the event of these exceptions, they will get messages such as:
java.lang.IllegalStateException: zip file is closed.

These kinds of error messages just spread confusion and I wish to do away with them (in the front end at least).
Any Ideas?