Question

Overview

UDP is a transport layer protocol that provides no reliability. This project aims to show how to implement extra features for the protocol in the application layer. The project will develop a new version of UDP protocol called UDPplus which provides reliable connection oriented between a client and a UDPplus sever. The UDPplus is implemented at application layer using UDP protocol only.

Basic Scenario

The UPDplus is a simple bank inquiry application where the client sends full name and receive the account name that is associated with this name as following

Name	Account No
Abdullah Ali	15324
Manal Abdullah	90781
Henry Markos	88125
Hisham Mansoor	62044

Client Process: the process reads the name from a user then sends it to the server which returns the account number. The process prints the account number to the user.

Server Process: the process remains ready to receive inquiries, once an inquiry is received it looks for the account associated with the name as it is showed in the table above. If the account is found the process returns the account number or returns “0000” as an error. III. Application Core Features

The basic scenario should be extended to implement the following features:

1. Connection oriented feature: the UPDplus should implement two way handshaking. The client should send a notification to the server in order to establish a new connection. If the server is available it will replay with the maximum number of messages the server can handle. If the server is not available (i.e. busy), it will replay with -1.
   1. You should implement the server to randomly response with a chance 20% not available.
   2. The client cannot send datagrams until a positive response received from the server.
   3. The port number for the server side is 9152.
   4. The port number for the client side should be random.

      server code

   5. package se;

      import java.io.*;

      import java.net.*;

      class Server {

        

          public static void main(String args[]) throws Exception {

              System.out .printf("Server Runing ");

              DatagramSocket serverSocket = new DatagramSocket(9876);

              byte[] receiveData = new byte[1024];

              byte[] sendData = new byte[1024];

             

              while(true) {

      DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);

      serverSocket.receive(receivePacket);

      String sentence = new String(receivePacket.getData());

      InetAddress IPAddress = receivePacket.getAddress();

             

      int port = receivePacket.getPort();

      String capitalizedSentence = sentence.toUpperCase();

      sendData = capitalizedSentence.getBytes();

      DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, port);

      serverSocket.send(sendPacket);

              }

          }

        }

client code

package se;

import java.io.*;

import java.net.*;

public class client { public static void main(String args[]) throws Exception {

    System.out.printf("client Runing :");

    BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));

    DatagramSocket clientSocket = new DatagramSocket();

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

    byte[] sendData = new byte[1024];

    byte[] receiveData = new byte[1024];

    String sentence = inFromUser.readLine();

    sendData = sentence.getBytes();

    DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, 9876);

    clientSocket.send(sendPacket);

    DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);

    clientSocket.receive(receivePacket);

   

    String modifiedSentence = new String(receivePacket.getData());

    System.out.println("FROM SERVER:" + modifiedSentence); clientSocket.close();

   

}

}

Answer 1

Server Code

import java.io.*;

import java.net.*;

class Server {

    public static void main(String args[]) throws Exception {

        System.out .println("Server Runing ");

        DatagramSocket serverSocket = new DatagramSocket(9876);

        byte[] receiveData = new byte[1024];

        byte[] sendData = new byte[1024];
        int i;
        int ans = 0;
        String name[] = new String[]{ "Abdullah", "Manal","Henry","Hisham"};
        String acc[] = new String[] {"15324","90781","88125","62044"};

        while(true) {

            ans = 0;
            DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);

            serverSocket.receive(receivePacket);

            String sentence = new String(receivePacket.getData());

            InetAddress IPAddress = receivePacket.getAddress();
            int port = receivePacket.getPort();
      
            for(i=0; i<4; i++)
            {
                String tmp = name[i];

                if(sentence.equals(tmp)==true)
                {
                    String capitalizedSentence = acc[i];
                    sendData = capitalizedSentence.getBytes();
                    DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, port);
                    serverSocket.send(sendPacket);
                    ans = 1;
                }
            }
            if(ans==0)
            {
                String err="0000";
                sendData = err.getBytes();
                DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, port);
                serverSocket.send(sendPacket);
            }
        }

    }

}

client code

import java.io.*;

import java.net.*;

public class client { public static void main(String args[]) throws Exception {

    BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));

    DatagramSocket clientSocket = new DatagramSocket();

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

    byte[] sendData = new byte[1024];

    byte[] receiveData = new byte[1024];

    System.out.println("Enter Name Of Customer");
    String sentence = inFromUser.readLine();

    sendData = sentence.getBytes();

    DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, 9876);

    clientSocket.send(sendPacket);

    DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);

    clientSocket.receive(receivePacket);

    String modifiedSentence = new String(receivePacket.getData());

    System.out.println("Account Number is :" + modifiedSentence);
  
    clientSocket.close();

}

}