Document Generation

[Joe Baldwin]

I have converted my entire datasource management over to Cayenne  
Modeler and it has made the coordination of the ORM part of my  
project one of the easiest and most reliable components to maintain  
and evolve.   I have two questions about generating project  
documentation:

What is the use-pattern is to document the Entities (i.e. generated  
Java classes) so that they will be visible to Javadoc.  (I was  
thinking that I could embed comments in the generated sub-classes,  
but then I was unsure how that would weather the changes I am making  
to the DB schema via Cayenne Modeler, or if that was even the  
smartest way to accomplish this.)

I have done some quick research and I can't seem to find a way to  
generate ER diagrams.  What tools, if any, are recommended that  
generate Entity-Relationship diagrams and are also compatible with  
Cayenne?

Thanks,
Joe