Sun Java System Application Server Enterprise Edition 8.2 Developer's Guide

MBean Notifications

All AMX MBeans that emit Notifications place a java.util.Map within the userData field of a standard Notification, which can be obtained via Notification.getUserData(). Within the map are zero or more items, which vary according to the Notification type. Each Notification type, and the data available within the Notification, is defined in its respective MBean or in an appropriate place.

Note that certain standard Notifications, such as do not and cannot follow this behavior.