As also described in the Hibernate book from King and Bauer: "With the adoption of Java™ 5 generics, the idea of a generic typesafe Data Access Object (DAO) implementation has become feasible. In this article, system architect Per Mellqvist presents a generic DAO implementation class based on Hibernate. He then shows you how to use Spring AOP introductions to add a typesafe interface to the class for query execution."