Here is one (of many) tutorials on using XDoclet with hibernate.
http://www.thogau.net/tutorials/pojo.html
See the section on Xdoclet and Hibernate.
Here is another one I like.
http://www.downside.ch/blog/?page_id=37
The version of XDoclet for the project
http://xdoclet.sourceforge.net/xdoclet/index.html
to use would be the latest 1.3.x snap shot (build it yourself).
http://xdoclet.sourceforge.net/xdoclet/install.html
Alternatively, get it from Appfuse since its kept up to date.
http://raibledesigns.com/wiki/Wiki.jsp?page=Downloads
I use XDoclet in one of my major projects so it will work. I suggest you try a simple example first (not using generic) to get the environment setup. Then move from there.
Hope this helps.