How to create a simple Server Client Application Using RUDP in Java?

Question

I was working on a simple application to transfer files between two machines using UDP, but that turned out to be lossy and unreliable, so while searching the Internet I found this project named Simple Reliable UDP here, but they don't have any documentation or any example code. So if there is any who can help me with this code I will be grateful because I'm newbie in Java. I started with writing simple server client app, but I got address already bind exception. To make clear I want to use UDP connections only that's why I'm trying to implement ReliableServerSocket and ReliableSocket.

  package stackoverflow;

  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  import net.rudp.ReliableServerSocket;
  import net.rudp.ReliableSocket;

  /**
  *
  * @author Nika
  */
  public class udpServer implements Runnable{
  ReliableServerSocket rss;
  ///ocket rs;
  ReliableSocket rs;
  public udpServer() throws IOException {
  rss= new ReliableServerSocket(9876);
  }
  public void run(){
  while (true){
    try {
        rs=(ReliableSocket)rss.accept();
        System.out.println("Connection Accepted");
        System.out.println(""+rs.getInetAddress());
        BufferedReader  inReader = new BufferedReader (new InputStreamReader (rs.getInputStream()));
    //BufferedWriter  outReader = new BufferedWriter (new OutputStreamWriter (rs.getOutputStream()));

        String str= ""+inReader.readLine();

        if(str.contains("UPLOAD")){
            System.out.println("Client wants to upload file");
        }else if(str.contains("D1")){
            System.out.println("Client wants to download file");
       }



    } catch (IOException ex) {
        Logger.getLogger(udpServer.class.getName()).log(Level.SEVERE, null, ex);
    }

  }

  }

      public static void main(String args[]) throws Exception  
   {
      System.out.println("UDP Server Executed");
     Thread t= new Thread( new udpServer());
             t.start();
   }


 }

Client Code here

      package stackoverflow;

      import java.io.BufferedWriter;
      import java.io.IOException;
      import java.io.OutputStreamWriter;
      import net.rudp.ReliableSocket;

      /**
      *
      * @author Nika
      */
     public class UdpFileClient {

     BufferedWriter outReader;
     ReliableSocket server;

    public UdpFileClient(boolean b1, boolean b2) throws IOException {

    if (b1) {
        server = new ReliableSocket("127.0.0.1", 9876);

        outReader = new BufferedWriter(new OutputStreamWriter(server.getOutputStream()));
        outReader.write("D1");
        System.out.println("Download Req Sent From Client");
        server.close();
        outReader.flush();
        outReader.close();
    }

    if (b2) {
        server = new ReliableSocket("127.0.0.1", 9876);
        outReader = new BufferedWriter(new OutputStreamWriter(server.getOutputStream()));
        outReader.write("UPLOAD");
        System.out.println("Upload Req Sent From Client");
        server.close();
        outReader.flush();
        outReader.close();
    }

}

public static void main(String args[]) throws Exception {
    System.out.println("UDP CLient Executed");
    new UdpFileClient(true, true);
}

}

I already know I can use TCP/IP, but it is kind of requirement for the project to use UDP. If any other way to send files in lossless way using UDP with good speed will also be helpful.

Thanks in advance!!

Answer 1

I tried RUDP and found that i was not printing my output, i know this is a silly mistake.

UDP Client package UDPClient;

  import java.io.IOException;
  import java.io.InputStream;
  import java.net.InetSocketAddress;
  import net.rudp.ReliableSocket;

  /**
  *
  * @author Nika
  */
  public class UDPtestc {
  ReliableSocket server;
   public UDPtestc() throws IOException {
     server = new ReliableSocket();
            server.connect(new InetSocketAddress("127.0.0.1", 9876));
    byte[] buffer = new byte[1024];
    int count,progress=0;
    InputStream in = server.getInputStream();
    while((count=in.read(buffer)) >0){
    progress+=count;
    System.out.println(""+progress);
    }
    server.close();            
    }

    public static void main(String[] args) throws IOException {
    new UDPtestc();
    }

    }

UDPserver

  package UDPServer;

  import java.io.FileInputStream; 
  import java.io.IOException;
  import java.io.OutputStream;
  import java.io.RandomAccessFile;
  import java.net.Socket;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  import net.rudp.ReliableServerSocket;
  import net.rudp.ReliableSocket;

  /**
  *
  * @author Nika
  */
  public class UDPtests implements Runnable {

  ReliableServerSocket rss;
  ReliableSocket rs;
  String file;

  FileInputStream bin;

  public UDPtests() throws IOException {
    rss = new ReliableServerSocket(9876);
    Thread serverthread = new Thread(this);
    serverthread.start();

   }

   public void run() {
    while (true) {
        try {
            rs =  (ReliableSocket)rss.accept();
            System.out.println("Connection Accepted");
            System.out.println("" + rs.getRemoteSocketAddress());

              file = "";
        Long size=0L;
             file += "10MB.txt";
                size+=10*1024*1024;

        RandomAccessFile r1= new RandomAccessFile(file,"rw");
        r1.setLength(size);
        byte[] sendData = new byte[1024];

        OutputStream os = rs.getOutputStream();
        //FileOutputStream wr = new FileOutputStream(new File(file));
        bin= new FileInputStream(file);
        int bytesReceived = 0;
        int progress = 0;
        while ((bytesReceived = bin.read(sendData)) > 0) {
            /* Write to the file */
            os.write(sendData, 0, bytesReceived);
            progress += bytesReceived;
            System.out.println(""+progress);
        }



        } catch (IOException ex) {
            Logger.getLogger(udpServer.class.getName()).log(Level.SEVERE, null, ex);
        }

    }
}

public static void main(String[] args) throws IOException {
    new UDPtests();
}

}

Soon i will post other tuts on RUDP if it will be possible.