nValidation should be easy to configure, be
robust on the client
side and either provide good out of the box messages or allow you to easily customize
them.
nStruts and Spring MVC
nuse Commons Validator – a mature
solution
nWebWork
nuses OGNL for powerful expressions -
client-side support very
new
nTapestry
nhas very robust validation - good messages
without need to customize
nJSF
nugly default messages, but easiest to
configure