If your war file is exploded then any changes to the jsp will NOT require a restart of the server.
The following link might help you:
Let me also add that if you just change the jsp file in a exploded war, you dont even have to touch the web.xml file for redeploying the application. The next time you use the jsp, the latest changes will be available to you. So it's as simple as making changes to the jsp(in the exploded war) and start seeing the changes you made.