课程目的：
With the knowledge you now have of the basics of the Java programming language, you can learn to write your own classes. In this lesson, you will find information about defining your own classes, including declaring member variables, methods, and constructors.
You will learn to use your classes to create objects, and how to use the objects you create.
This lesson also covers nesting classes within other classes, and enumerations。
1、构建自己的类，包括变量申明、方法以及构造器；
2、学会创建对象，并且使用对象；
3、涉及到Nesting class 和 enumerations.
原文：http://www.cnblogs.com/clebean/p/7498643.html