The downloadable JDK documentation comes with fully working example code to do this. Look in the docs\guide\rmi\archives\rmiservlethandler directory, where you'll also find instructions on setup and use.
Can it be helpful for what I want to implement. I want to have an applet that is automatically updated from a Servlet over http. This will be a Obsever/Observable pattern along with a Server push type of thing. Please help me in this regard...
Server push to an applet is not generally possible due to firewalls. Consider a periodic pull by the applet instead. I would use plain HTTP, and leave RMI out of it.