Hands-On Design Patterns with Java

Learning the complete OOP class

Throughout this chapter, we made use of a Bicycle class. As illustrated in the following, we created a hierarchy to demonstrate inheritance as a key feature of OOP. All objects inherit from the Object class in Java. Our hierarchy has Bicycle inheriting from TwoWheeled, which inherits from Vehicle, which inherits from Object:

Bicycle class hierarchy

For our Bicycle class to work with the intended hierarchy, we created classes for Vehicle and TwoWheeled. Here are those classes:

public class Vehicle {}public class TwoWheeled extends Vehicle {}

The Vehicle and TwoWheeled classes do not offer anything to the Bicycle ...