Hi,
An error boundary event is a logical error inside a process definition, so no support for Java exceptions there.
In other words, you can throw a logical error using a error end event that can be caught be an error boundary event.
But you can catch a Java exception within a Java service task and take an error sequence flow from there.
So you can add two sequence flows to the Java service task, one for normal process flow (without the exception occurring), and one for error process flow with the sub process you want to execute in case an exception does occur inside the Java service task.
To implement the error routing logic in a Java service task you should implement the ActivityBehaviour interface instead of a JavaDelegate.
You can find more information in the userguide, under Java service task - Handling exceptions.
Best regards,
