Exception Handler Stack

JADE allows the developer to arm up to 128 local exception handlers for each method for a specific process, and up to 128 global exception handlers for each process. As each handler is armed or disarmed it is added to or removed from the local or global exception handler 'stack'. When an exception is raised, JADE passes the exception object to the most‑recently armed local exception handler in the stack that is armed to handle that type of exception and control is passed to that handler. The class specified in the exception handler arming statement (on exception‑class do exception‑handler‑method‑name) is what determines whether a specified exception is passed to a particular handler.

If no local exception handler handles a specified exception (or all return Ex_Pass_Back), the global exception handler stack is examined to look for a suitable global exception handler, starting with the most‑recently armed handler.

If an exception handler returns Ex_Pass_Back (documented later in this white paper), control is passed down to the next most‑recently armed exception handler that is capable of handling the exception.