继承

package bbb;
class Instrument{
 public void play(){
  System.out.println("弹奏乐器");
}
}
class Wind extends Instrument{
 public Wind(){
 }
  public void playnew(){
  }
  public void play(){
   System.out.println("弹奏wind!");
  }
 
 public void play2(){
  System.out.println("调用wind的play2");
 }
}
class Brass extends Instrument{
 public Brass(){
 }
 public void playnew(){
 }
 public void play(){
  System.out.println("弹奏brass!");
 }
 public void play2(){
  System.out.println("调用brass的play2");
 }
}
 public class Music{
   public static void tune(Instrument i){
    i.play();
 }
 
 public static void main(String args[]){
  Wind w=new Wind();
  Brass b=new Brass();
  tune(w);
  tune(b);
 }
 }
 

结果：弹奏wind!
           弹奏brass!