有没有知道这是怎么回事

public class lianxi1 {
    public static void main(String[] args) {
        CPU cpu=new CPU();
        cpu.setSpeed(10.0);
        cpu.getSpeed();
        PC pc=new PC();
        pc.setCpu(cpu);
    }
    
    public static class CPU {
        private Double speed;
        
        public Double getSpeed() {
            return speed;
        }
        
        public void setSpeed(Double speed) {
            this.speed = speed;
        }
    }
 
 
    
    public static class PC {
        private CPU cpu;
        private HardDisk hardDisk;
        public CPU getCpu() {
            return cpu;
        }
        public PC(CPU cpu) {        //构造方法重载
            this.cpu = cpu;
        }
        
        public PC() {  //构造方法
        }
        public HardDisk getHardDisk() {
            return hardDisk;
        }
        public void setHardDisk(HardDisk hardDisk) {
            this.hardDisk = hardDisk;
        }
        
        public void setCpu(CPU cpu) {
            this.cpu = cpu;
        }
        
        
        public void  show(){
            System.out.println("CPU的速度"+cpu.getSpeed());
            System.out.println("硬盘容量"+hardDisk.getAmount());
            
        }
    }
 
 
    
    public class sun extends Father{
        public void  show(){
            System.out.println("sun");
        }
    }
    
    
    public class Father {
        int a=1;
        
        public int getA() {
            return a;
        }
        
        public void setA(int a) {
            this.a = a;
        }
        public void show(){
            System.out.println("father");
        }
    }
 
 
    
    public abstract class chouxiang {
        abstract void chouxiangfangfa();
    }
    public class chouxiangImpl extends chouxiang {
        @Override
        void chouxiangfangfa() {
            
        }
    }
 
 
 
    
     class MyException extends  Exception{
        public void show(){
            System.out.println("Exception");
        }
    }
}
 

把每个class的代码都发出来
点修改问题，然后点这里