In one of our legacy web applications, we leveraged Struts 1.2 with Hibernate 3.2.2GA. We utilized the hiberate.cfg.xml configuration file that defined our mappings to our Entity annotated beans. We also created DAO interface objects and HibernateDAO objects that extended a GenericHibernateDAO template class for the Entity Bean that implemented our DAO interface. The previous developers opted to create a DAO Factory class as a singleton that was accessed from within the Struts Actions to instantiate the DAO object for our action and methods were called to perform whatever business was necessary on the DAO objects.

In the Struts 1.2 release, JPA wasn't referenced. Is there an advantage as I move to Struts2 and Spring being embedded in the web application to look at JPA in how its used with Spring/Hibernate over this prior methodology of using Hibernate alone? Is there any particular types of scenarios where this behavior really shines versus where I will likely see little improvement in speed and ease of development?