java中接口实现多态举例

public class Test4 {

     public static void main(String[] args){  
         Instrument ss[]={new Wind(),new Piano()};  
         for(Instrument i:ss){  
             tun(i);  
         }  
     }  
     public static void tun(Instrument i){  
         i.play();  
     }  
} 

interface Instrument{  
    void play();  
}  
class Wind implements Instrument{  
    public void play(){  
        System.out.println("wind can play");  
    }  
}  
class Piano implements Instrument{  
    public void play(){  
        System.out.println("Piano can play");  
    }  
}