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211 ira 1 
import java.io.*;
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import java.util.*;
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import java.net.*;
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import java.util.regex.*;
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public class P2_Server
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{
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    private static int portNumber = 1337;
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    private static int dropEvery = -1;
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    private static int sendCount = 1;
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    private static DatagramPacket packet;
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    private static DatagramSocket socket;
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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 (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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        System.out.println ("Recieved Packet. Len: " + packet.getLength());
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        String s = new String (buf, 0, packet.getLength() /*- 1*/);
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        System.out.println ("RcvdPacket: |" + s + "|");
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        return s;
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    }
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    public static boolean writePacket (String msg)
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    {
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        if (sendCount == dropEvery && !msg.equals("QUIT"))
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        {
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            System.out.println ("Dropped a packet");
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            sendCount = 0; // reset the sendCount
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            return true;   // "Fake" send
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        }
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        else { sendCount++; }
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        System.out.println ("Num sent: " + sendCount);
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        InetAddress address = packet.getAddress();
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        int port = packet.getPort();
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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 (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 int calcDrops (String s)
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    {
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        String dropRegex = "^DROP(\\d*)(.*)$";
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        Pattern p = Pattern.compile(dropRegex);
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        Matcher m = p.matcher(s);
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        if (m.matches())
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            return Integer.parseInt(m.group(1));
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        return -1;
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    }
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    public static void main (String[] args) throws Exception
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    {
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        boolean done = false;
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        socket = new DatagramSocket(portNumber);
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        packet = null;
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        String s;
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        // Try to get a "timeout info" packet
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        while (!done)
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        {
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            s = readPacket (8);
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            dropEvery = calcDrops(s);
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            if (dropEvery != -1)
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            {
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                done = true;
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                System.out.println ("dropEvery: " + dropEvery);
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            }
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        }
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        done = false;
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        // Keep reading until we get a quit packet
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        while (!done)
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        {
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            s = readPacket (5);
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            // Check and see if we got a quit message
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            if (s.equals("QUIT"))
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            {
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                done = true;
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                writePacket(s);
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                continue;
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            }
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            try {
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                s = P2_EncDec.convert4B (s);
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            } catch (IllegalArgumentException e) {
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                System.out.println ("Recieved a bad packet");
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                s = "BADVAL";
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            }
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            writePacket (s);
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        }
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    }
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}