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Rev Author Line No. Line
211 ira 1 
 
2 
import java.io.*;
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import java.net.*;
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import java.util.*;
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public class P2_Client
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{
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    private static int soTimeout = 3000; // 3000 ms timeout = 3 sec
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    private static DatagramSocket socket;
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    private static DatagramPacket packet;
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    private static int portNumber = 1337;
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    public static String readPacket (int maxlen)
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    {
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        byte[] buf = new byte[maxlen];
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        packet = new DatagramPacket (buf, buf.length);
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        try {
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            socket.receive (packet);
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        } catch (SocketTimeoutException e) {
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            System.out.println ("Read timed out, requesting retransmit");
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            return null;
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        } catch (PortUnreachableException e) {
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            System.out.println ("Caught PortUnreachableException, are you" +
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                                " sure the server is running?");
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            System.exit(1);
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        } catch (IOException e) {
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            System.out.println ("Caught exception in readPacket()");
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            e.printStackTrace();
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            return null;
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        }
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        return new String (buf, 0, packet.getLength()/*- 1*/);
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    }
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    public static boolean writePacket (String msg) throws Exception
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    {
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        InetAddress address = InetAddress.getLocalHost();
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        int port = portNumber;
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        byte[] buf = msg.getBytes();
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        packet = new DatagramPacket (buf, buf.length, address, port);
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        try {
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            socket.send (packet);
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        } catch (PortUnreachableException e) {
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            System.out.println ("Caught PortUnreachableException, are " +
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                                "you sure the server is running?");
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            System.exit(1);
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        } catch (IOException e) {
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            System.out.println ("Caught exception in writePacket()");
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            e.printStackTrace();
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            return false;
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        }
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        return true;
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    }
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    public static void main (String[] args) throws Exception
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    {
212 ira 60 
        int dropHowMany = 0;
211 ira 61 
        socket = new DatagramSocket();
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        socket.connect (InetAddress.getLocalHost(), portNumber);
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        socket.setSoTimeout (soTimeout);
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        BufferedReader kbd = new BufferedReader (
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                                 new InputStreamReader (
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                                     System.in));
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212 ira 69 
        try {
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            dropHowMany = Integer.parseInt(args[0]);
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        } catch (ArrayIndexOutOfBoundsException e) {
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            System.err.println ("You need to call the program with \'java P2_Client <num>\'");
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            System.exit(1);
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        }
211 ira 75 
 
212 ira 76 
        writePacket ("DROP" + dropHowMany);
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211 ira 78 
        System.out.print ("% decode: ");
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        String msg = kbd.readLine();
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        String reply;
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        boolean done = false;
82 
 
83 
        while (!done)
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        {
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            writePacket (msg);
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            reply = readPacket(5);
87 
 
88 
            while (reply == null)
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            {
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                System.out.println ("Packet lost, retransmitting...");
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                writePacket (msg);
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                reply = readPacket(5);
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            }
94 
 
95 
            if (reply.equals("QUIT"))
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            {
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                done = true;
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                continue;
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            }
100 
 
101 
            System.out.println ("-> reply: " + reply);
102 
            System.out.print ("% decode: ");
103 
            msg = kbd.readLine();
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        }
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    }
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}
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