A Module That Allows You to Declare Real Exception Classes in Perl
http://search.cpan.org/dist/Exception-Class

Exception::Class allows you to declare exception hierarchies in your modules in
 a "Java-esque" manner.

It features a simple interface allowing programmers to 'declare' exception
 classes at compile time. It also has a base exception class,
 Exception::Class::Base, that can be easily extended.

It is designed to make structured exception handling simpler and better by
 encouraging people to use hierarchies of exceptions in their applications,
 as opposed to a single catch-all exception class.

This module does not implement any try/catch syntax. Please see the
 "OTHER EXCEPTION MODULES (try/catch syntax)" section for more information on
 how to get this syntax.

You will also want to look at the documentation for Exception::Class::Base,
 which is the default base class for all exception objects created
 by this module.

  Author:	Dave Rolsky <autarch@urth.org>