7.8. Exercises: Inheritance¶
Work on these exercises in the IntelliJ
java-web-dev-exercises project. Add a new package called
technology to your
Class design: Create a new class called
Computer. Before you add any more code, know that you will need to add two additional classes:
SmartPhone. Before you start coding anything inside these classes, diagram how the three classes are going to be related to each other. Remember to add properties and methods to your diagram!
For a parent class add 3 properties, 2 methods, and a constructor.
For a child class add at least 1 additional property and 1 additional method.
Class implementation: Implement your design and test it in a
Try to add three JUnit tests per class!
Abstract class design: Consider the group of classes that you designed. Suppose you had a web program that used these classes, and you needed to assign a unique ID to every object created from one of these classes within the application. Therefore, each such class should have an
Idproperty, and no two objects created from any of the classes may have the same value for
Id. Create an abstract class,
AbstractEntity, that contains the behavior for assigning and accessing such a unique ID for each class that extends it. Add this class to your program above, and add
AbstractEntityto the class hierarchy in the correct place.