I want to prevent the user from running my java application multiple times in parallel.

To prevent this, I have created a lock file when am opening the application, and delete the lock file when closing the application.

When the application is running, you can not open an another instance of jar. However, if you kill the application through task manager, the window closing event in the application is not triggered and the lock file is not deleted.

How can I make sure the lock file method works or what other mechanism could I use?