（1）实现单重继承并借助接口实现多重继承。

（2）实现方法的继承与覆盖。

（3）实现方法（包括构造方法）的重载。

（4）在程序中利用包进行类的逻辑组织。

（5）编写基于图形界面的程序。

-(1) for single re-use of interface inheritance and multiple inheritance. (2) Implementation of the inheritance and coverage. (3) implementation methods (including constructor) of the overload. (4) packets used in the program logic of the class organization. (5) preparation program based on the graphical interface.