Zarar Siddiqi’s blog post on java.net talks about building a generic toString() method to dump out the contents of all the attributes of an instance, which of course is invaluable for debugging.
The thing is, one of the number one rules of architecture is to appreciate and understand what is already out there, what has been done before, and what you can reuse.
The Commons Lang library of useful code includes a ReflectionToStringBuilder class which does exactly the same thing.