Maven project for a JMXMP connector server with configurable port, based on:

http://stackoverflow.com/questions/11413178/how-to-enable-jmxmp-in-tomcat

Usage ($CATALINA_HOME/conf/server.xml):
<Listener className="javax.management.remote.extension.JMXMPLifecycleListener" port="5555" />

And don't forget to add the jmxmp jars to $CATALINA_HOME/lib
See http://stackoverflow.com/questions/11412560/where-to-download-jmxmp

Note
Also make sure the JMX client also adds the jmxremote_optional.jar to the classpath.
For VisualVM: visualvm --cp:a jmxremote_optional.jar