Struts2

http://www.mkyong.com/tutorials/struts-2-tutorials/
http://struts.apache.org/development/2.x/
http://struts.apache.org/development/2.x/docs/debugging-struts.html
http://joeljil.wordpress.com/2010/05/31/struts2/
http://javapostsforlearning.blogspot.com.es/2012/07/configuring-struts-2.html