For JBossCache with WebSphere, I got such error.
Anyone knows this class can be found in which JAR?

[6/9/05 10:37:51:764 EDT] 7d426d82 ServletInstan E SRVE0100E: Did not realize init() exception thrown by servlet init: javax.servlet.ServletException: Error while defining class: org.jboss.cache.TreeCache
This error indicates that the class: Error while defining class: org.jboss.system.ServiceMBeanSupport
This error indicates that the class: org.jboss.mx.util.JBossNotificationBroadcasterSupport
could not be located while defining the class: org.jboss.system.ServiceMBeanSupport
This is often caused by having the class at a higher point in the classloader hierarchy
Dumping the current context classloader hierarchy:
==> indicates defining classloader
*** indicates classloader where the missing class could have been found
==>[0]