java第四章编程题（初学篇）

代码：

 /*
    test.java
 */
 package test;
 public class test {
     public static void main(String args[] )
     {
         CPU ccp= new CPU();
         HardDisk hhd=new HardDisk();
         PC pc =new PC();
         ccp.setSpeed(2200);
         hhd.setAmount(200);
         pc.setCPU(ccp);
         pc.setHardDisk(hhd);
         pc.show();
     }

 }

 /*
   PC.java
 */
 package test;
 public class PC {
     CPU cpu ;
     HardDisk HD ;
     void setCPU(CPU cp)  { cpu=cp;  }
     void setHardDisk(HardDisk hd){ HD=hd ;}
     void show()
     {
         System.out.println("CPU的Speed: "+cpu.getSpeed());
         System.out.println("HardDisk: "+HD.getAmount());
     }
 }

 /*
   CPU.java
 */
 package test;

 public class CPU {
      int speed;
      void setSpeed(int m){speed=m;}
      int getSpeed(){return speed ;}
 }

 /*
   HardDisk.java
 */
 package test;

 public class HardDisk {

     int amount;
     void setAmount(int m){    amount=m;}
     int getAmount(){return amount;}
 }