Chat Client

ChatClient.java

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

public final class ChatClient {
    private static final String SERVER_HOST      = "localhost";
    private static final String TERMINAL_MESSAGE = "quit";
    private static final int BUFFER_SIZE         = 4096;

    public static void main(String[] args) {
        if (args.length < 1) {
            System.err.println("Port number must be designated !!");
            System.exit(1);
        }

        Socket socket = null;

        try {
            socket = new Socket(ChatClient.SERVER_HOST, Integer.parseInt(args[0]));

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

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

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

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

                char[] buffer = new char[ChatClient.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(ChatClient.TERMINAL_MESSAGE)) {
                        System.out.println("Quit Chat. Good Bye !!");
                        System.exit(0);
                   } else if (message.indexOf("\n") != -1) {
                        break;
                   }
                }

                output.write('\n'); 
                output.flush();

                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(ChatClient.TERMINAL_MESSAGE) || sb.toString().trim().equals("")) {
                    System.out.println("Quit Chat. Good Bye !!");
                    break;
                } else { 
                    System.out.println("Receive Message >> " + sb.toString());
                }
            }
        } catch (UnknownHostException error) {
            error.printStackTrace();
        } catch (IOException error) {
            error.printStackTrace();
        } finally {
            try {
                if (socket != null) {
                    socket.close();
                }
            } catch (IOException error) {
                error.printStackTrace();
            }
        }
    }
}