This week's book giveaway is in the OCAJP forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide 1Z0-808 and have Jeanne Boyarsky & Scott Selikoff on-line! See this thread for details.
I have been running a mock Java certification test based on an applet at: http://www.lanw.com/java/javacert/ for several years. I have also been running a servlet based test engine in connection with LANWrights classes for over a year. Your first decision is: applet or servlet? Next you need to decide on the way to represent the questions. We have been using a custom script language, but are converting to XML. Using XML seems to give more flexibility, especially when we want to re-use the questions in different environments. I am using simple Perl scripts for storing the results of the mock Java exam. The servlets write the results to a simple "flat" file. I don't really see the need for a database unless your question generation or answer recording requirements are complex. Bill