接口做参数

接口做参数(2009-02-21 18:11:19)

标签：it java 编程

     如果一个方法的参数是接口类型,就可以将任何实现该接口类的实例的引用传递给该接口参数,那么接口参数就可以回调类实现的接口方法.

 

 interface SpeakHello
{
 void speakHello();
}
class Chinese implements SpeakHello
{
 public void speakHello()
  {
   System.out.println("中国人问好:你好,吃饭了吗?");
  }
}
class English implements SpeakHello
{
 public void speakHello()
 {
  System.out.println("外国人问好:你好,今天天气不错");
 }
}
class KindHello
{
 public void lookHello(SpeakHello lookhello)
 {
  lookhello.speakHello();
 }
}
public class InterfaceArgs {
   public static void main(String args[])
   {
    KindHello kh=new KindHello();
    kh.lookHello(new Chinese());
    kh.lookHello(new English());
   }
}