For now, just some pointers to get you started:
Note that in contrast with e.g. flowscript, these actions work stateless: they don't store the form object serverside but rebuild it on each request (which is very fast BTW). When doing things this way, ValueChangedEvents will not work and output widgets will lose their value between requests. You can of course store the form in the session to solve this.
The apples block contains sample code on how to do use the Woody binding from Java. See BindingWoodyApple.java