Section 20.1. The Sample Application

20.1. The Sample Application

In order to focus on the features and requirements of Hibernate, we are using a relatively simple application as an example. The application will track the students, professors, classes, and departments of a university. Through this framework, we'll be able to demonstrate the configuration, mapping, and manipulation of persistent domain objects.

The application will consist of five major domain classes:

Department

Will contain multiple classes and professors but no students

UniversityClass

Will have a single professor and multiple students, will belong to a single department, and will have a single syllabus

Syllabus

Will belong to a UniversityClass; every Syllabus will be unique to a specific UniversityClass

Professors

Will teach one or more classes but have a single primary department

Students

Will attend multiple classes but have no formal association with either a Professor or a Department

In addition, we'll introduce the Person interface to serve as a common ancestor between Professor and Student. Last, we need to add a layer to manage persistent domain objects. For other applications, you might decide to add a Data Access Object (DAO) with a façade layer on top. We decided that a DAO layer was overkill for such a small application, so we omitted it.