Subversion Repositories programming

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

 * File: P1Client.java

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

 * Class: CS380 - Computer Networking

 *

 * Assignment: Project #1

 * Date Last Modified: 2006-01-18

 *

 * Purpose: Opens a connection to a server running on port 1337 on the

 *          local machine. Sends 10 1024 Byte payloads to the server,

 *          measuring the time it takes to recieve them back.

 *          It uses this data to calculate the RTT between the applications.

 *

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

import java.io.*;

import java.net.*;

import java.util.Date;

public class P1Client

{

    public static final String exitSeq = "QUIT";

    public static final String hostName = "localhost";

    public static final int portNumber = 1337;

    public static final int numPackets = 200000;

    public static final int packetSize = 1024;

    private static Date startTime;

    private static Date stopTime;

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

    {

        Socket sendSocket = null;

        PrintWriter out = null;

        BufferedReader in = null;

        try

        {

            sendSocket = new Socket (hostName, portNumber);

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

            in = new BufferedReader (new InputStreamReader(

                                         sendSocket.getInputStream()));

        }

        catch (UnknownHostException e)

        {

            System.err.println ("Can't resolve hostname: " + hostName);

            System.exit(1);

        }

        catch (IOException e)

        {

            System.err.println ("Couldn't get I/O for " +

                                "the connection to: " + hostName);

            System.exit(1);

        }

        String packet = generatePacket (packetSize);

        String response = new String();

        int i = 0;

        /* Start the timer */

        startTime = new Date();

        for (i=0; i<numPackets; i++)

        {

            out.println (packet);

            response = in.readLine();

        }

        /* Stop the timer */

        stopTime = new Date();

        /* Calculate and print all timing info */

        printTimingInfo(startTime, stopTime);

        /* Cleanup */

        out.close();

        in.close();

        sendSocket.close();

    }

    public static String generatePacket (int size)

    {

        String packet = new String();

        int i = 0;

        for (i=0; i<size; i++)

            packet += "Z";

        return packet;

    }

    public static void printTimingInfo (Date startTime, Date stopTime)

    {

        long totalTime = (stopTime.getTime() - startTime.getTime());

        double rtt = (double)totalTime / (double)numPackets;

        double totalBytes = (double)packetSize * (double)numPackets;

        double bw  = totalBytes / (double)totalTime * (double)1000.0 /* ms */;

        System.out.println ("Time for " + numPackets + " packets (millisec): "

                            + totalTime);

        System.out.println ("RTT per packet: " + rtt);

        System.out.println ("Total Bandwidth: " + bw + " Bytes / sec");

    }

}