java interface 用法

import java.io.*;
import java.util.*;
import java.util.regex.*;

interface myinterface
{
        public void output();
}

public class tmp implements myinterface
{
        public void output()
        {
                System.out.println("output");
        }

        public static void main(String args[]) throws Exception
        {
                myinterface t = new tmp();
                t.output();
        }
}