If you were to do this with a Linux server you could set up a cron job that executes the file you want.
On windows you would use the windows task scheduler..

I use this for php, so I guess it should be the same for jsp, no matter what server you're using.

The command to run on linux would look soemthing like:
wget -q http://www.yourdomain.com/yourscript.jsp > /dev/null