Chapter 8. Frameworks and Reuse: Designing with Interfaces and Abstract Classes

Chapter 7, "Mastering Inheritance and Composition," explains how inheritance and composition play major roles in the design of object-oriented (OO) systems. This chapter expands on this theme and introduces the concepts of a Java interface and an abstract class.

Java interfaces and abstract classes are a powerful mechanism for code reuse, providing the foundation for a concept we will call contracts . This chapter covers the topics of code reuse, frameworks, contracts, Java interfaces, and abstract classes. At the end of the chapter, we'll work through an example of how all these concepts can be applied to a real-world situation.