java类中定义接口

今天看到一个java类中定义了接口，写个备忘录，记录一下

 package com.gxf.test;

 public class Test_interface {
     public interface show{
         public void show();
     }
     static class TestInterface implements show{

         @Override
         public void show() {
             System.out.println("this is interface!");

         }

     }

     public static void main(String []args){
         TestInterface testInterface = new TestInterface();
         testInterface.show();
     }
 }