UDP Socket Programming - File transfer

// Socket Programing – Datagram Sockets

// Client Server Communication

// File Transfer

// Server Program

import java.io.*;

import java.net.*;

import java.util.*;

public class UDPFileServer

{

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

     {

          DatagramSocket ds;

          DatagramPacket dp_send;

          DatagramPacket dp_rec;

         

          final int buf_size = 512;

          final int port = 1500;

         

          byte msg_rec[] = new byte[buf_size];

          byte msg_send[] = new byte[buf_size];

         

          try

          {

              ds = new DatagramSocket(port);

             

              dp_rec = new DatagramPacket(msg_rec, buf_size);

              ds.receive(dp_rec);

                  

              String filename = new String(dp_rec.getData()).trim();

                            

              InetAddress DA = dp_rec.getAddress();

              int destport = dp_rec.getPort();

                 

              System.out.println("Requested file : "+filename);  

             

              FileInputStream fin = new FileInputStream(filename);

              int i = 0;

              while(true)

              {

                   int ch = fin.read();

                   if(ch==-1)

                        break;

                   msg_send[i]=(byte)ch;

                   i++;

                  

              }

             

              fin.close();

             

            dp_send = new DatagramPacket(msg_send, msg_send.length, DA, destport);

              ds.send(dp_send);

             

          }

          catch(Exception e)

          {

              System.out.println("Exception " + e);

          }

     }

}

// Socket Programing – Datagram Sockets

// Client Server Communication

// File Transfer

// Client Program

import java.io.*;

import java.net.*;

import java.util.*;

public class UDPFileClient

{

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

     {

          DatagramSocket ds;

          DatagramPacket dp_send;

          DatagramPacket dp_rec;

         

          final int port = 1500;

          final int buf_size = 512;

         

          Scanner s = new Scanner(System.in);

         

          byte[] msg_send = new byte[buf_size];    

          byte[] msg_rec = new byte[buf_size];

             

          try

          {

              ds = new DatagramSocket();

              System.out.print("Enter file name : ");

              String data = s.nextLine();

             

              msg_send = data.getBytes();

              InetAddress DA = InetAddress.getByName("localhost");

             

              dp_send = new DatagramPacket(msg_send, msg_send.length, DA, port);

              ds.send(dp_send);

             

              dp_rec = new DatagramPacket(msg_rec, buf_size);

              ds.receive(dp_rec);

                  

              String filedata = new String(dp_rec.getData()).trim();

              System.out.println(filedata);

         

          }

          catch(Exception e)

          {

              System.out.println("Exception " + e);

          }

     }

}