ChatClient.java

/**
 * ChatClient.java
 *
 * This program implements a simple multithreaded chat client.  It connects to the
 * server (assumed to be localhost on port 7654) and starts two threads:
 * one for listening for data sent from the server, and another that waits
 * for the user to type something in that will be sent to the server.
 * Anything sent to the server is broadcast to all clients.
 *
 * The ChatClient uses a ClientListener whose code is in a separate file.
 * The ClientListener runs in a separate thread, receives messages form the server,
 * and displays them on the screen.
 *
 * Data received is sent to the output screen, so it is possible that as
 * a user is typing in information a message from the server will be
 * inserted.
 *
 */

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;

import java.net.Socket;

import java.util.Scanner;

public class ChatClient {
  /**
   * main method.
   * @params not used.
   */
  public static void main(String[] args) {
    try {
      Scanner keyboard = new Scanner(System.in);
      System.out.print("Please enter a Username: ");
      String userName = keyboard.nextLine();
      String hostname = "localhost";
      int port = 7654;

      //System.out.println("Connecting to server on port " + port);
      Socket connectionSock = new Socket(hostname, port);

      DataOutputStream serverOutput = new DataOutputStream(connectionSock.getOutputStream());

      System.out.println("Connection made.\n");

      // Start a thread to listen and display data sent by the server
      ClientListener listener = new ClientListener(connectionSock);
      Thread theThread = new Thread(listener);
      theThread.start();
      boolean firstPass = true;
      // Read input from the keyboard and send it to everyone else.
      // The only way to quit is to hit control-c, but a quit command
      // could easily be added.
      while (true) {
        if (firstPass) {
          serverOutput.writeBytes(userName + "\n");
          firstPass = false;
        }
        String data = userName + ": " + keyboard.nextLine();
        serverOutput.writeBytes(data + "\n");

        // If user types goodbye chat ends
        String[] checkForGoodbye = data.split(":",2);
        if (checkForGoodbye[1].length() > 7
            && (checkForGoodbye[1].substring(0, 8).equals(" goodbye")
            || checkForGoodbye[1].substring(0,8).equals(" Goodbye")
            || checkForGoodbye[1].substring(0,8).equals(" GOODBYE"))) {
          System.out.println("** EXITING APPLICATION **");
          System.exit(0);
        }
      }
    } catch (IOException e) {
      System.out.println(e.getMessage());
    }
  }
} // MtClient