/**

* Java. Level 2. Lesson 6

* Simple server for chat

*

* @author Sergey Iryupin

* @version 0.1 dated Jan 13, 2018

*/

import java.io.*;

import java.net.*;

class SimpleServer {

final int SERVER_PORT = 2048;

final String SERVER_START = "Server is started...";

final String SERVER_STOP = "Server stopped.";

final String CLIENT_JOINED = " client joined.";

final String CLIENT_DISCONNECTED = " disconnected";

final String EXIT_COMMAND = "exit"; // command for exit

public static void main(String[] args) {

new SimpleServer();

}

SimpleServer() {

int clientCount = 0;

System.out.println(SERVER_START);

try (ServerSocket server = new ServerSocket(SERVER_PORT)) {

while (true) {

Socket socket = server.accept();

System.out.println("#" + (++clientCount) + CLIENT_JOINED);

new Thread(new ClientHandler(socket, clientCount)).start();

}

} catch (Exception ex) {

System.out.println(ex.getMessage());

}

System.out.println(SERVER_STOP);

}

/**

* ClientHandler: service requests of clients

*/

class ClientHandler implements Runnable {

BufferedReader reader;

PrintWriter writer;

Socket socket;

String name;

public ClientHandler(Socket clientSocket, int clientCount) {

try {

socket = clientSocket;

reader = new BufferedReader(

new InputStreamReader(socket.getInputStream()));

writer = new PrintWriter(socket.getOutputStream());

name = "Client #" + clientCount;

} catch(Exception ex) {

System.out.println(ex.getMessage());

}

}

@Override

public void run() {

String message;

try {

do {

message = reader.readLine();

System.out.println(name + ": " + message);

writer.println("echo: " + message);

writer.flush();

} while (!message.equalsIgnoreCase(EXIT_COMMAND));

socket.close();

System.out.println(name + CLIENT_DISCONNECTED);

} catch(Exception ex) {

System.out.println(ex.getMessage());

}

}

}

}