I'd like to add a third filter every Web Application should have: A monitoring filter that monitors performance of all server resources such as Serlvets, JSPs, GIFs, JPGs, HTML, CSS and more.
You can see the results of this filter by going to http://www.fdsapi.com, selecting 'Live Demo' and then going to the JAMon stats page. Every time you access a JSP or Servlet or other resources stats are automatically tracked.
The filter is very simple (start(), and stop()) and can be viewed at
steve - http://www.jamonapi.com