组合、继承和代理的区别

 1 public class Computer {
 2     public Computer() {
 3         CPU cpu=new CPU();
 4         RAM ram=new RAM();
 5         Disk disk=new Disk();
 6     }
 7 }
 8 class CPU{    }
 9 class RAM{    }
10 class Disk{    }

 1 public class PlaneDelegation{    
 2     private PlaneControl planeControl;    //private外部不可访问
 3     /*
 4      * 飞行员权限代理类，普通飞行员不可以开火
 5      */
 6     PlaneDelegation(){
 7         planeControl=new PlaneControl();
 8     }
 9     public void speed(){
10         planeControl.speed();
11     }
12     public void left(){
13         planeControl.left();
14     }
15     public void right(){
16         planeControl.right();
17     }
18 }
19 
20 final class PlaneControl {//final表示不可继承，控制器都能继承那还得了。。
21     protected void speed() {}
22     protected void fire() {}
23     protected void left() {}
24     protected void right() {}
25 }