selective-repeat-java/SelectiveRepeatReceiver.java at master · danyal-s/selective-repeat-java · GitHub

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/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
packageselectiverepeatreceiver;

importjava.io.BufferedReader;
importjava.io.IOException;
importjava.io.InputStreamReader;
importjava.io.PrintWriter;
importstaticjava.lang.Thread.sleep;
importjava.net.Socket;
importjava.util.Arrays;
importjava.util.Scanner;

/**
 *
 * @author Danyal
 */
publicclassSelectiveRepeatReceiver {

publicstaticvoidmain(String[] args) throwsInterruptedException
 {
Scannerscan = newScanner(System.in);
try
 {
System.out.println("Enter the IP Address: ");
StringIP = scan.next();
System.out.println("Enter port number: ");
Stringport = scan.next();
Socketusocket = newSocket(IP, Integer.parseInt(port));
BufferedReaderinbuffer = newBufferedReader(newInputStreamReader(usocket.getInputStream()));
PrintWriteroutbuffer = newPrintWriter(usocket.getOutputStream(), true);
intrn = 0;
booleannaksent = false, ackneeded = false;
booleandatareceived = false;
intm = Integer.parseInt(inbuffer.readLine());
boolean[] marked = newboolean[m];
Stringdata[] = newString[m];
for(inti = 0; i < marked.length; i++)
 {
marked[i] = false;
 }
while(!datareceived)
 {
outbuffer.println("FRAME");
sleep(300);
intframe = Integer.parseInt(inbuffer.readLine());
if(frame != rn && !naksent && frame > rn)
 {
outbuffer.println("NACK" + rn);
System.out.println("Received frame number" + frame + " when " + rn + " was expected. Sending NACK" + rn + ".");
System.out.println("Sent NACK" + rn);
naksent = true;
continue;
 }
elseif(frame < rn)
 {
System.out.println("Discarded frame number " + frame + " as it's < rn");
continue;
 }

if(isBetween(frame, rn, rn + m, m)&&(!marked[frame]))
 {
System.out.println("Stored " + frame + " at " + frame + ".");
data[frame] = "Frame" + Integer.toString(frame);
marked[frame] = true;
System.out.println("Marked " + frame + " as received.");
while(marked[rn])
 {
System.out.println(rn + " is marked. Moving to " + (rn + 1) + ".");
rn++;
ackneeded = true;
if(rn >= marked.length)
 {
datareceived = true;
break;
 }
 }
if(ackneeded)
 {
System.out.println("ACK is needed. Sending out ACK" + rn + ".");
outbuffer.println("ACK"+rn);
ackneeded = false;
naksent = false;
 }
 }
System.out.println(Arrays.toString(data));
 }
System.out.println("Data successfully retreieved. Final output is:\n" + Arrays.toString(data));
outbuffer.println("FINISH");
inbuffer.close();
outbuffer.close();
usocket.close();
 }
catch(IOExceptione)
 {
e.printStackTrace();
 }
 }
staticbooleanisBetween(intnum, intn1, intn2, intmod)
 {
if(num == n1)
returntrue;

while(n1 != n2)
 {
n1 = (n1 + 1)%mod;
if(num == n1)
returntrue;
 }
returnfalse;
 }
}