Some other program altogether -- or a previously executed copy of the same program -- may already be running, bound to that same port. What port are you trying to listen on?
i used 3306,5050,1080, e.t.c after some time i am getting the error. its because i am failing to close a socket connection after i exit from the system.i am simulating my client server app.
There is already some application running at that port.many times even if you close the application the jvm keeps on running..in that case you can use the program manager of your app;ication for checking and killing any unnecessay program that might be using that port..some of the program make thread that make use of the port and if the threads are not demon then they would continue to run even after the main method..so in that case it still migh be using the port...so kill that application that is using the port and then again start the server...