In this chapter we start with a discussion regarding the origins of the data access pattern and examine the related data transfer object.

We show how the data access object and factory pattern can work together. We continue with an introduction to the Java persistence API and object relational mapping.

We show how to improve a simple implementation of a data access object can be improved using generics

We finish with a discussion regarding the role of data access objects in modern Java EE applications.

Professional Java EE Design Patterns