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");
    }
}