Java™ How To Program (Early Objects), Tenth Edition

Rethrowing Exceptions

Line 32 of Fig. 11.5 rethrows the exception. Exceptions are rethrown when a catch block, upon receiving an exception, decides either that it cannot process that exception or that it can only partially process it. Rethrowing an exception defers the exception handling (or perhaps a portion of it) to another catch block associated with an outer try statement. An exception is rethrown by using the throw keyword, followed by a reference to the exception object that was just caught. Exceptions cannot be rethrown from a finally block, as the exception parameter (a local variable) from the catch block no longer exists.

When a rethrow occurs, the next enclosing try block detects the rethrown exception, and that try block’s catch ...