How are you doing dude? I'm not sure that I understand correctly what you are
searching for, but a
few things poped-up in my mind:

1- DB4O @http://www.db4o.com/
2- BDB JE @ http://www.sleepycat.com/products/bdbje.html

and finally

3- http://www.prevayler.org/wiki.jsp

I guess Prevayler is probably what you are looking for.