Subversion Repositories programming

/*******************************************************************************

 * File: P3_Client.java

 * Author: Ira W. Snyder (devel@irasnyder.com)

 * License: GNU General Public License v2

 * Class: CS380 - Computer Networking

 *

 * Assignment: Project #3

 * Date Last Modified: 2006-02-15

 *

 * Purpose: Implement a client that will request an IP Address from the

 * P3_Server running on TCP Port 1337. Once it gets a lease, it waits for

 * the server to tell it that the lease has expired.

 ******************************************************************************/

import java.net.*;

import java.io.*;

public class P3_Client

{

    /* Instance Variables */

    private static IPAddr ip;

    private static String hw;

    private static final String hostName = "localhost";

    private static final int portNumber = 1337;

    /**

     * Method: main

     * Purpose: The main() function, which handles requesting an IP Address,

     * and then closes when the lease expires.

     */

    public static void main (String[] args) throws Exception

    {

        Socket socket = null;

        PrintWriter out = null;

        BufferedReader in = null;

        BufferedReader kbd = null;

        String s = new String();

        boolean running = true;

        // Set up the socket, and input and output streams

        try

        {

            socket = new Socket (hostName, portNumber);

            out = new PrintWriter (socket.getOutputStream(), true);

            in = new BufferedReader (new InputStreamReader (

                                         socket.getInputStream()));

            kbd = new BufferedReader (new InputStreamReader (System.in));

        }

        catch (UnknownHostException e)

        {

            System.err.printf ("Can't resolve hostname: %s\n", hostName);

            System.exit (1);

        }

        catch (IOException e)

        {

            System.err.printf ("Couldn't get I/O for the connection to: %s\n", hostName);

            System.err.printf ("Is the P3_Server running?\n");

            System.exit (2);

        }

        // Ask the user for the Hardware Address

        System.out.print ("Please type your Hardware Address: ");

        hw = kbd.readLine();

        // Send Hardware Address to the server

        out.printf ("req IP %s\n", hw);

        // Print every message sent back from the server, until the lease expires

        while (running)

        {

            // Get messages from the server

            s = in.readLine();

            System.out.println (s);

            // Stop when the lease expires

            if (s.equals("IP Lease Time Expired"))

                running = false;

        }

        // Tell the user that we are quitting

        System.out.println ("Client Exiting");

        // Clean up all the sockets

        out.close();

        in.close();

        socket.close();

    }

}