16.6. Summary

In this chapter, we looked at layered applications and some important patterns and best practices. We discussed how you can design a web application with Hibernate and implement the Open Session in View pattern. You now know how to create smart domain models and how to separate business logic from controller code. The flexible Command pattern is a major asset in your software design arsenal. We looked at EJB 3.0 components and how you can further simplify a POJO application by adding a few annotations.

Finally, we discussed the persistence layer extensively; you wrote data-access objects and integration tests with TestNG that exercise the persistence layer.