Listing Open Source Web Frameworks in Java

I've stumbled acros a nice listing of available open source web frameworks for Java:

http://java-source.net/open-source/web-frameworks.

Are there really too many Java web frameworks?

Java ServerFaces Tutorial

An excellent tutorial about Java ServerFaces can be found at RoseIndia.net: JSF Tutorial. I use this link regularly as reference. When I search information about how to do something in JSF, I often end up on this site. It's an excellent resource about everything related to software engineering.