Is there any good generic JPA DAO implemenation?

Question

According this article, generic JPA DAO(Data Access Object) is a pretty nice pattern.

Is there any good implementation?

Answer 1

You could take a look into the Spring Data JPA.

A few new concepts were introduced into Spring Data JPA, for instance the Query creation based on the method name, so you can declare a method like findById(String id) and the "generic" implementation will interpret the method's name and execute something like select Entity from Entity where id = 'given string'

Methods like findByNameAndLastName(String name, String lastName) or even findByNameOrInternalId(String name, int internalId) are supported too.

Answer 2

Just wanted to mention a couple more generic dao implementations for JPA:

• Generic DAO toolkit - http://code.google.com/p/generic-dao/
• Related Question in SO - Single DAO & generic CRUD methods (JPA/Hibernate + Spring)
• A good blog article on JPA DAO - http://blog.xebia.com/2009/03/09/jpa-implementation-patterns-data-access-objects/