This is a great article, but I also had some trouble getting the example to work.
I followed the exact steps in the article and was getting a 404 error when submitting the login.jsp form. I changed my web.xml file to the following:
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
This is assuming you have your .jsp pages in the root of the project directory “TOMCAT_ROOT/webapps/onjava/”. With this fix there is no need to change the action for the form.
Alex, thanks for heading me in the right direction!