EXPLAIN EACH LINE OF CODE

import java.net.ServerSocket; import java.net.Socket; import java.util.ArrayList; import java.io.BufferedInputStream; import java.net.Socket; import java.io.DataOutputStream; import java.io.EOFException; import java.io.IOException; import java.io.DataInputStream;

public class ChatServer {

static ArrayList connectedClients = new ArrayList(); public static void main(String[] args) { if (args.length != 1) { //System.err.println("Usage: ChatServer "); return; }

try { int port = Integer.parseInt(args[0]);

ServerSocket serverSocket = new ServerSocket(port); while (true) { Socket client = serverSocket.accept();

ClientHandler newClient = new ClientHandler(client); connectedClients.add(newClient); newClient.start(); }

} catch (Exception e) { e.printStackTrace(); } } }

// changes right here

class ClientHandler extends Thread { Socket clientSocket; DataOutputStream output; DataInputStream input; String name = "";

public ClientHandler(Socket clientSocket) { this.clientSocket = clientSocket; }

@Override public void run() { // Initialize our input and output streams to operate off of the given client try { output = new DataOutputStream(clientSocket.getOutputStream()); input = new DataInputStream(new BufferedInputStream(clientSocket.getInputStream())); } catch (IOException e) { e.printStackTrace(); }

// Always run while the service is operational while (true) { try { // Receive String message = input.readUTF(); if (name.equals("")) { name = message; } else { System.out.println(message);

// Send to all clients for (ClientHandler client : ChatServer.connectedClients) { if (client.name.equals(name) || client.clientSocket.isClosed()) { continue; } client.output.writeUTF(name + ": " + message); } } } catch (EOFException ex) { break; } catch (IOException e) { e.printStackTrace(); break; } } try { clientSocket.close(); output.close(); input.close(); ChatServer.connectedClients.remove(this); } catch (IOException e) { e.printStackTrace(); } } }