Excellent chart of component isolation.  Presentation, business, integration sit on top of the development framework and event logging capabilities.  Seriously, very nice.

 

Nothing like a framework to ease your burden.  Check it out, more than 50 java development frameworks are described and linked.  Of course the usual suspects are here: Cocoon, Struts, and Java Server Faces.  But also includes Tapestry, RSF, ZK and JAT.  Wow, glad we are finally moving into this space...