I am running Apache Jserv on a Linux platform, with automatic class-reloading.




I have a singleton class called Scheduler.java that runs as a Thread, and a few servlets that get a handle to this thread.






public class Scheduler extends Thread {



private static Scheduler scheduler;




public static synchronized Scheduler getInstance(){



if (scheduler == null){


scheduler = new Scheduler();


scheduler.start();


}


return scheduler;



}





The problem I have is that if I recompile either the Scheduler class or the servlets that get an instance of it,
I end up with multiple instances of Scheduler running.



Even if I DELETE all the classes and recompile them, I still have old threads running somewhere in the background.



The only way to get rid of them is to stop and restart the web server.



I would like to know why the threads are still running ( I did NOT do setDaemon(true), if that matters)
and how to stop them.



Also, setting scheduler = null does not stop the thread from running.