I’ve recently been experimenting with XDoclet and I have to say that it really seems to simplify things. But when you think about it, it seems like somewhat of a round trip.

Developers have gone to great lengths to externalize properties and deployment-related information out of source code and into XML files. They have gone so far as to require you to define all of this information externally. For example, Struts uses the struts-config.xml file to define the interaction between pages in a Web application. So far as I know, you cannot define the action responses directly in your code.

So, XDoclet is now providing us with a way to pull all of the externalized definitions back into the source code. Why not just provide an underlying framework or interface to define these things directly in the code? Why do we have to resort to JavaDoc to define system behavior?