Summary
nStruts is a powerful framework and is used widely, but it has its problems
ncomplicated, difficult to learn, tedious to set up
ncodebase isn't great--numerous deprecations attest to this
nActionForm pattern is limiting because bean binding (mapping request parameters to beans) is primitive (only string properties are particularly useful). You'll probably have to copy properties from an ActionForm to an application bean.
nTwo other open source frameworks, WebWork and Maverick may work better and are worth investigating
nhttp://www.opensymphony.com/webwork/
nhttp://mav.sourceforge.net/