From: <forums_at_java.net>
Date: Mon, 14 Mar 2011 08:35:50 -0500 (CDT)
Custom mbeans feature is not available in GlassFish 3.1. A workaround is to
create and register MBeans programatically. In your application, use a
singleton object to handle the initialization or use a "Run only once"
lifecycle method. You can also consider using lifecycle events to register
MBeans -
http://download.oracle.com/docs/cd/E19798-01/821-1752/beamc/index.html