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();
    }
}