Interface using Java in NetBeans

import java.io.*;

interface Interface{

    final int a = 10;

    void display();

}

public class p30_implementinterface implements Interface{

    public void display(){

        System.out.println("Tushar");

    }

    public static void main (String[] args){

        p30_implementinterface t = new p30_implementinterface();

        t.display();

        System.out.println(a);

    }    

}