The Spring Framework provides a great implementation of the DAO/DTO pattern set as described in any J2EE patterns book. Have you had a chance to check that out? I am a huge fan of Hibernate as an ORM solution (not just another way to write queries, but that's another discussion altogether). But, if you feel like doing the dirty work yourself, see some of the examples provided by Spring. They are already doing what you are describing here - no need to reinvent the wheel.