EchoServer

//EchoClient JAVA program
//send BYE to disconnect
//runs at port 5000


import java.io.*;
import java.net.*;
import java.util.*;

class EchoServer
{
    public static void main(String arg[])
    {

        try
        {

            //Socket for Server
            ServerSocket serverSocket=new ServerSocket(5000);

            //Socket to connect to Client
            Socket clientSocket=serverSocket.accept();


            try {

                //Scanner for reading message from Client
                Scanner in = new Scanner(clientSocket.getInputStream());

                //PrintWriter for Sending message to Client
                PrintWriter p = new PrintWriter(clientSocket.getOutputStream(),true);

                //Send Greeting to Client
                p.println("Hello! Welcome to EchoServer. Enter BYE to Quit");

                boolean exit=false;

                //While Client has something to say, repeat this..
                while(!exit&&in.hasNextLine())
                {
                    String input=in.nextLine();                         //Message from Client
                    System.out.println("Client Says: " + input);
                    if(input.trim().equals("BYE"))                      //trim() removes white spaces around the received text
                    {
                        System.out.println("Disconnecting...");
                        p.println("Disconnecting...");                  //Message to Client
                        exit=true;
                    }
                    else
                    {
                        p.println(input);                               //Message to Client
                    }
                }
            }
            finally
            {
                clientSocket.close();                                   //Close Client Socket
                serverSocket.close();                                   //Close Client Socket
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }

    }
}