/*
 * Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle or the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */ 

import java.io.*;
import java.net.*;
import java.util.*;


public class UdpHttpClient {

    public static int BUFLEN = 1024;

    public static void main(String[] args) throws IOException {

        if (args.length != 1) {
             System.out.println("Usage: java UdpHttpClient <hostname>");
             return;
        }

            // get a datagram socket
        DatagramSocket socket = new DatagramSocket();

            // send request
        byte[] command =  buildCommand(args[0].trim());
        InetAddress address = InetAddress.getByName(args[0].trim());
        DatagramPacket sentPacket 
	    = new DatagramPacket(command, command.length, address, 80);

	// debug
	System.out.println(new String(command));

        socket.send(sentPacket);
    
            // get response
	byte[] recvBuf = new byte[BUFLEN];
	DatagramPacket recvPacket
	    = new DatagramPacket(recvBuf, recvBuf.length);

        socket.receive(recvPacket);

	    // display response
        String received = new String(recvPacket.getData(), 0, 
				     recvPacket.getLength());
        System.out.println("Message from the server : " + received);
    
        socket.close();
    }

    public static byte[] buildCommand(String host) {

	String cmd = new String("HEAD /");
	cmd += " HTTP/1.1\n";
	cmd += "Host: " + host + "\n";
        cmd += "\r\n\r\n";
	
	return cmd.getBytes();
    }

}