Seems you are new in the Java and have written good modularized code though some more modifications need to do .
Follow what Jeanne has suggested.
One very minute mistake i am observing is your servlet don't have doGet() or doPost() methods which is very important to get data from your request .
See what exactly happens is when you are submitting the form having method="get" or "post" then all form parameters/data goes to your request and then to the servelet method doGet() or doPost() where you can process request data.
So you need to add doGet() or doPost() method based on your form method and then can processRequest() from it .