Chat Server

ChatServer.java

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

public final class ChatServer {

    private static final int LISTEN_PORT         = 9999;
    private static final String TERMINAL_MESSAGE = "quit";
    private static final int BUFFER_SIZE         = 4096;

    public static void main(String[] args) {
        ServerSocket serverSocket = null;
        Socket       clientSocket = null;

        try {
            serverSocket = new ServerSocket(ChatServer.LISTEN_PORT);

            System.out.println("Listen (" + ChatServer.LISTEN_PORT + ") ...");
            clientSocket  = serverSocket.accept();

            while (true) {
                Reader input  = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
                Writer output = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()));

                //for Receive Message
                StringBuilder sb = new StringBuilder(ChatServer.BUFFER_SIZE);

                System.out.println("Waiting ...");

                int c = 0;

                while ((c = input.read()) != -1 ) {
                    if (c == '\n') {
                        break;
                    }

                    sb.append((char)c);
                }

                if (sb.toString().trim().toLowerCase().equals(ChatServer.TERMINAL_MESSAGE) || sb.toString().trim().equals("")) {
                    System.out.println("Quit Chat. Good Bye !!");
                    break;
                } else { 
                    System.out.println("Receive Message >> " + sb.toString());
                }

                System.out.print("Send Message    >> ");

                Reader stdin = new BufferedReader(new InputStreamReader(System.in));

                char[] buffer = new char[ChatServer.BUFFER_SIZE];

                while (stdin.read(buffer) != -1) {
                   //Send
                   output.write(buffer);

                   String message = String.valueOf(buffer);  //String message = new String(buffer, 'UTF-8');

                   if (message.trim().toLowerCase().equals(ChatServer.TERMINAL_MESSAGE)) {
                        System.out.println("Quit Chat. Good Bye !!");
                        System.exit(0);
                   } else if (message.indexOf("\n") != -1) {
                        break;
                   }
                }

                output.write('\n'); 
                output.flush();
            }
        } catch (SocketTimeoutException error) {
            System.err.println("TIMEOUT");
            error.printStackTrace();
        } catch (IOException error) {
            error.printStackTrace();
        } finally {
            try {
                if (clientSocket != null) {clientSocket.close();}
                if (serverSocket != null) {serverSocket.close();}
            } catch (IOException error) {
                error.printStackTrace();
            }
        }
    }
}