URL Demo in java

import java.io.*;

import java.net.*;

public class URLDemo

{

     public static void main(String[]args)

      {

                   try

                   {

                         URL u=new URL ("http://www.yahoomail.com/index.html");

                         URLConnection ucon=u.openConnection();

                           for(int i=0;i<20;i++)

                           {

                            String key=ucon.getHeaderFieldKey(i);

                            String val=ucon.getHeaderField(key);

                            System.out.println(key+"\t=\t"+val);

                           }

                   }catch(Exception e)

                      {

                        System.out.println(e);

                       }

         }

}