JMX

With  eclipse 

• go to Help > Software Updates > Find and Install...
• check Search for new features to install and click Next >
• click on New Remote Site...
• in the New Update Site window, type:
• Name: eclipse-jmx
• URL: http://eclipse-jmx.googlecode.com/svn/trunk/net.jmesnil.jmx.update/
• click on OK
• check eclipse-jmx and click on Finish
• expand the features and select the latest one. Then click on Next >
• check I accept the terms in the license agreement and click on Next >
• click on Finish
• once all the plug-ins are downloaded, click on Install All
• finally, when ask to restart Eclipse, click on Yes

With JBOSS TOOL SET

http://blag.oxbeef.net/?q=node/5

Monitor Java Processes( Tomcat) with JCONSOLE
https://wiki.internet2.edu/confluence/display/CPD/Monitoring+Tomcat+with+JMX


Monitoring the Java VM
http://opennms.org/wiki/Monitoring_the_Java_VM