How to implement a single instance Java application?

Question

Sometime I see many application such as msn, windows media player etc that are single instance applications (when user executes while application is running a new applicatio

Answer 1

I have found a solution, a bit cartoonish explanation, but still works in most cases. It uses the plain old lock file creating stuff, but in a quite different view:

http://javalandscape.blogspot.com/2008/07/single-instance-from-your-application.html

I think it will be a help to those with a strict firewall setting.