I've been trying for a couple of days now to get HttpServletRequest.getUserPrincipal() to return something other than null, with absolutely no success. I'm starting to think there's a bug in JBoss, but since I can't find the bug database anywhere I can't check.
If anybody has a working example of using getUserPrincipal() with JBoss3.2.1 would you mind replying with a zip/tar/whatever that includes your jboss-web.xml, login-config.xml, web.xml, and source code files for your HttpServlet (or the Action if you're using Struts) and LoginModule classes?
Make sure the requested web page is secured (in the web.xml). For unsecured pages, getUserPrincipal() will always return null.