From a Java program, I needed to test if another Java program was running. My first thought was that the jps tool already
provides me with this information. But I was being curious how he does that. So I had a look at its bytecode, and created
a very simplified version of the jps tool.

package jps;

import java.net.URISyntaxException;
import java.util.Set;

import sun.jvmstat.monitor.*;

public class MyJps
{

   public static void main(String[] args) throws MonitorException, URISyntaxException
   {
      MonitoredHost monitoredHost = MonitoredHost.getMonitoredHost("localhost");
      Set<Integer> activeVms = monitoredHost.activeVms();
      for (int psId : activeVms)
      {
         MonitoredVm monitoredVm = monitoredHost.getMonitoredVm(new VmIdentifier(String.valueOf(psId)));
         String mainClass = MonitoredVmUtil.mainClass(monitoredVm, false);
         System.out.println(mainClass + " [" + psId + "]");
      }
   }

}

It uses classes from the tools.jar, so do not forget to include it in your classpath if you run this class. From there, it is
not difficult to write a small method that test if a given Java process is running. Also, it is not difficult to change this
code to make it work on a distant server.