Java client/server application

AIM: Write a java  that implements a simple client/server application. The client sends data to a server. The server receives the data, uses it to produce a result and then sends the result back to the client. The client displays the result on the console. For ex: The data sent from the client is the numbers and the result produced by the server is the addition of that numbers

Client program:

import java.io.*;

import java.net.*;

public class AddClient

 {

            public static void main(String args[])

             {

                        Socket addSocket = null;

                        DataOutputStream strmToServer = null;

                        DataInputStream strmFromServer = null;

                        final String server = "localhost";

                        int i, currentSum, num;

                        try

                         {

                                    addSocket = new Socket(server, 8000);

                                    strmToServer = new DataOutputStream(addSocket.getOutputStream());

                                    strmFromServer = new DataInputStream(addSocket.getInputStream());

                                    System.out.println("Connected to Server ...");

                        }

                        catch (UnknownHostException ex)

                        {

                                    System.out.println("Unable to find server: " + server);         

                                    System.exit(1);

                        }

                        catch (IOException ex)

                        {

                        System.out.println("Unable to open I/O stream to server: " + server);

                        System.exit(1);

                        }

                        try

                        {

                                    strmToServer.writeInt(args.length-1);

                                    currentSum = Integer.parseInt(args[0]);

                                    for (i=1; i<args.length; i++)

                                    {

                                                num = Integer.parseInt(args[i]);

                                                strmToServer.writeInt(currentSum);

                                                strmToServer.writeInt(num);

                                                currentSum = strmFromServer.readInt();

                                    }

                                    System.out.println("Sum: " + currentSum);

                                    strmFromServer.close();

                                    strmToServer.close();

                                    addSocket.close();

                        }

                        catch (Exception ex)

                        {

                                    ex.printStackTrace();

                         }

            }

}

Server program:

import java.net.*;

import java.io.*;

public class AddServer

 {

            public static void main(String args[])

            {

                        Socket socket = null;

                        ServerSocket serverSocket = null;

                        DataOutputStream strmToClient = null;

                        DataInputStream strmFromClient = null;

                        int i, numAdditions, sum, num1, num2;

                        try

                        {

                                    serverSocket = new ServerSocket(8000);

                                    System.out.println("Server is starting ...");

                        }

                        catch (Exception ex)

                        {

                                    System.out.println("Unable to start server");

                                    System.exit(1);

                        }

                        try

                        {

                                    while (true)

                                    {

                                                socket = serverSocket.accept();

                                                System.out.println("Serving client: " + socket.getInetAddress());

                                                strmToClient = new DataOutputStream(socket.getOutputStream());

                                                strmFromClient = new DataInputStream(socket.getInputStream());

                                                numAdditions = strmFromClient.readInt();

                                                for (i=0; i<numAdditions; i++)

                                                {

                                                            num1 = strmFromClient.readInt();

                                                            num2 = strmFromClient.readInt();

                                                            System.out.println(num1 + " + " + num2);

                                                            sum = num1 + num2;

                                                            strmToClient.writeInt(sum);

                                                }

                                                socket.close();

                                    }

                        }

                        catch (IOException ex)

                        {

                                    System.out.println("Unable to open I/O stream to server: " + ex);

                                    System.exit(1);

                        }

            }

}

Output: