This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori 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.