Can Data Binding with Jaxb do this?

[R Olson]

I'm been using Jaxb to write XML files. For each class created by Jaxb (e.g. X.java), I wrote my own derivative class (e.g. Y.java) with additional data and methods, since I needed richer classes with more than the skeleton setters and getters and referenced data that Jaxb provides. So, when I build the set of objects, I construct my class (Y) rather than the original Jaxb created X class, and the XML file is created correctly. So far so good.
Now I want to go the other way and read XML files, and have Jaxb construct the objects of *my* derived classes, rather than the skeleton Jaxb generated classes. But, I don't see a way to do that. In other words, for XML element X, I want:
At build time:
- Jaxb writes class X.java
- I provide class Y.java, which is derived from X.java
At run time:
- Jaxb reads XML file
- For each X Element, Jaxb instantiates my derived Y class (not the X class).
I don't think Jaxb's ability to take a user-provided class name solves the problem. That just makes Jaxb generate the source under a different class name, but still doesn't instantiate my class.
Is there a way to do what I want, or am I asking too much? Seems to me like this would be a common need.
Thanks,
Ron

[Peter Chase]

I'd like to be able to do this, too!