import java.io.*;
import java.net.*;
import java.util.Scanner;
     public class EchoClient{
          public static void main(String[] args){
             try{
                 Socket socket=new Socket("127.0.0.1",5000);
                 BufferedReader in = new BufferedReader(
                 new InputStreamReader(socket.getInputStream()));
                PrintWriter out= new PrintWriter(socket.getOutputStream(),true);
                 Scanner sc=new Scanner(System.in);
                 String message,response;
             while(true){
                 System.out.print("Enter message:");
                 message=sc.nextLine();
                out.println(message);
                response=in.readLine();
          System.out.println("Server:"+response);
         if(message.equalsIgnoreCase("exit"))
    break;
   }
   socket.close();
   sc.close();
   }catch(IOException e){
   e.printStackTrace();
    }
  }
}

import java.io.*;
import java.net.*;
     public class EchoServer{
     public static void main(String[] args){
     try{
         ServerSocket serverSocket=new ServerSocket(5000);
        System.out.println("Echo Server is waiting for a client...");
        Socket socket=serverSocket.accept();
        System.out.println("Clent Connected");
BufferedReader in=new BufferedReader(
new InputStreamReader(socket.getInputStream()));
PrintWriter out= new PrintWriter(
socket.getOutputStream(),true);
String message;
while((message=in.readLine())!=null){
System.out.println("Received: "+message);
if(message.equalsIgnoreCase("exit")){
out.println("Connection closed.");
}
out.println("Echo:" +message);
}
socket.close();
serverSocket.close();
}
catch(IOException e){
e.printStackTrace();}
}
}