1/a) Socket server source

import java.io.*;
import java.net.*;
  
public class Provider{
      ServerSocket providerSocket;
      Socket connection = null;
      ObjectOutputStream out;
      ObjectInputStream in;
      String message; 	
      Provider() {}
      void run() {
	try{
		providerSocket = new ServerSocket(8080, 10);
		connection = providerSocket.accept();
		out = new ObjectOutputStream(connection.getOutputStream());
		in = new ObjectInputStream(connection.getInputStream());
		
                      do {
			try {
				message = (String)in.readObject();
				System.out.println("client>" + message);
				if (message.equals("bye")) sendMessage("bye");
			}
			catch(ClassNotFoundException classnot){
				System.err.println("Data received in unknown format");
			}
		} while(!message.equals("bye"));
	}
	catch(IOException ioException){
		ioException.printStackTrace();
	}
	finally{
		try {
			in.close();
			out.close();
			providerSocket.close();
		}
		catch(IOException ioException){
			ioException.printStackTrace();
		}
	}
}
      
void sendMessage(String msg) {
	try {
		out.writeObject(msg);
		out.flush();
		System.out.println("server>" + msg);
	}
	catch(IOException ioException){
		ioException.printStackTrace();
	}
}
      
public static void main(String args[]) {
	Provider server = new Provider();
	while(true){
		server.run();
	}
}
}

1/b.) Client source

import java.io.*;
import java.net.*;
 
public class Requester{
      Socket requestSocket;
      ObjectOutputStream out;
      ObjectInputStream in;
      String message;
      Requester(){}
void run() {
	try{
		requestSocket = new Socket("localhost", 8080);
		out = new ObjectOutputStream(requestSocket.getOutputStream());
		in = new ObjectInputStream(requestSocket.getInputStream());
		do {
			try {
				sendMessage("Hello szerver");
				sendMessage("bye");
                                      message = (String)in.readObject();
			}
			catch(Exception e){
				System.err.println("data received in unknown format");
			}    
		} while(!message.equals("bye"));
	}
	catch(UnknownHostException unknownHost){
		System.err.println("You are trying to connect to an unknown host!");
	}
	catch(IOException ioException){
		ioException.printStackTrace();
	}
	finally{
		try{
			in.close();
			out.close();
			requestSocket.close();
		}
		catch(IOException ioException){
			ioException.printStackTrace();
		}
	}
}
  
void sendMessage(String msg) {
	try {
		out.writeObject(msg);
		out.flush();
		System.out.println("client>" + msg);
	}
	catch(IOException ioException){
		ioException.printStackTrace();
	}
}
 
public static void main(String args[]) {
	Requester client = new Requester();
	client.run();
}
}