This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
You can. You can also use a hammer to drive in a screw. But it's the wrong tool for the job. Servlets are meant to respond to requests, context listeners are meant to perform setup. Use the right tool for the job.