[Ch15] Client uses nio

import java.awt.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.net.Socket;

import java.net.InetSocketAddress;

import java.nio.ByteBuffer;

import java.nio.channels.SocketChannel;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

public class SimpleChatClient {

  public static void main(String[] args) throws IOException {

    Socket socket = setUpNetworking();

    SocketChannel socket = setUpNetworking();

    ClientUI clientUI = new ClientUI();

    clientUI.go(socket);

    threadExecutor.shutdown();

  }

  private static Socket setUpNetworking() throws IOException {

    Socket socket = new Socket("127.0.0.1", 5000);

    System.out.println("Networking established. Local port: " + socket.getLocalPort());

    return socket;

  private static SocketChannel setUpNetworking() throws IOException {

    SocketChannel socketChannel = SocketChannel.open(new InetSocketAddress("localhost", 5000));

    System.out.println("Networking established. Local address: " + socketChannel.getLocalAddress());

    return socketChannel;

  }

}

class ClientUI {

  private JTextArea incoming;

  public void go(Socket socket) {

  public void go(SocketChannel socket) {

    JFrame frame = new JFrame("Ludicrously Simple Chat Client");

    JPanel mainPanel = new JPanel();

    incoming = new JTextArea(15, 50);

  public static class SendButtonListener implements ActionListener {

    private final JTextField outgoing;

    private final PrintWriter writer;

    private final SocketChannel channel;

    public SendButtonListener(JTextField outgoingMessage, Socket socket) {

      try {

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

      } catch (IOException e) {

        throw new RuntimeException(e);

      }

    public SendButtonListener(JTextField outgoingMessage, SocketChannel channel) {

      outgoing = outgoingMessage;

      this.channel = channel;

    }

    public void actionPerformed(ActionEvent ev) {

      byte[] message = outgoing.getText().getBytes();

      ByteBuffer buffer = ByteBuffer.wrap(message);

      try {

        writer.println(outgoing.getText());

        writer.flush();

        channel.write(buffer);

      } catch (Exception ex) {

        ex.printStackTrace();

      }

}

class IncomingReader implements Runnable {

  private final BufferedReader reader;

  private final SocketChannel channel;

  private final JTextArea incomingMessageArea;

  public IncomingReader(JTextArea incomingMessageArea, Socket socket) throws IOException {

  public IncomingReader(JTextArea incomingMessageArea, SocketChannel channel) {

    this.incomingMessageArea = incomingMessageArea;

    reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));

    this.channel = channel;

  }

  public void run() {

  }

  private void processMessages() {

    String message;

    ByteBuffer buffer = ByteBuffer.allocate(256);

    try {

      while ((message = reader.readLine()) != null) {

      while (channel.isOpen()) {

        channel.read(buffer);

        String message = new String(buffer.array()).trim();

        System.out.println("read " + message);

        incomingMessageArea.append(message + "\n");

      } // close while

        buffer.clear();

      }

    } catch (Exception ex) {

      ex.printStackTrace();

    }