but if I try invoking the stop()/start() methods from the jmx-console of the jboss...though it prints out the debug statements I have in there...the methods dont seem to work - when I invoke them from the jmx-console...
for ex: If I invoke the stop() method...it doesnt seem to nullify the singleton instance...
Does the control enter the stop method? You can check this by adding System.out.println statements in that method. And if it does enter this method, then the invoking the stop method from jmx-console is working.
When you say the nullify of singleton instance does not work, how did you
test it? Are you sure the instance is not getting created again after you have set the instance to null. Also, can you post the code of this MBean where you are doing these operations?