Description of the illustration employee_classes.jpg

This image is a diagram of the class structure for the data access objects (DAO) for the Java application. On the left the EmployeeRepository class represents the inteface for the DAO. Two implementations classes inherit from this class. The EmployeeRepositoryImpl class is the implementation class for the ArrayList persistence store. The EmployeeRepositoryDB class is the implementation class for the Oracle database implementation. The EmployeeService class uses either of the two implementation classes to create the actual REST web service.