As of Java 1.5 (Java 5.0), the sun jdk started shipping with some useful tools for viewing information about running java processes. To provide quick and easy access to some of the information these commands provide, eclim exposes the command :Jps.
Note
For more information on the jdk tools you may view the online documentation.
When invoked it will open a window containing information about the current processes and some links for viewing additional info (depending upon availability of required tools on your platform).
Example content: