[Ch15] Resetting chat to "classic" IO with my updated separation and executor service. (4c0a7978) · Commits · examples / Head First Java 3rd Edition

src/main/java/ch15/SimpleChatClient.java

+25 −30

Changes for src/main/java/ch15/SimpleChatClient.java: 25 added lines, 30 removed lines.
Original line number	Diff line number	Diff line
		@@ -4,19 +4,18 @@ import javax.swing.*;
		import java.awt.*;
		import java.awt.event.ActionEvent;
		import java.awt.event.ActionListener;
		import java.io.BufferedReader;
		import java.io.IOException;
		import java.net.InetSocketAddress;
		import java.nio.ByteBuffer;
		import java.nio.CharBuffer;
		import java.nio.channels.SocketChannel;
		import java.nio.charset.StandardCharsets;
		import java.io.InputStreamReader;
		import java.io.PrintWriter;
		import java.net.Socket;
		import java.util.concurrent.ExecutorService;
		import java.util.concurrent.Executors;

		public class SimpleChatClient {

		public static void main(String[] args) throws IOException {
		SocketChannel socket = setUpNetworking();
		Socket socket = setUpNetworking();

		ClientUI clientUI = new ClientUI();
		clientUI.go(socket);
		@@ -27,17 +26,17 @@ public class SimpleChatClient {
		threadExecutor.shutdown();
		}

		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;
		private static Socket setUpNetworking() throws IOException {
		Socket socket = new Socket("127.0.0.1", 5000);
		System.out.println("networking established");
		return socket;
		}
		}

		class ClientUI {
		private JTextArea incoming;

		public void go(SocketChannel socket) {
		public void go(Socket socket) {
		JFrame frame = new JFrame("Ludicrously Simple Chat Client");
		JPanel mainPanel = new JPanel();
		incoming = new JTextArea(15, 50);
		@@ -64,19 +63,21 @@ class ClientUI {

		public static class SendButtonListener implements ActionListener {
		private final JTextField outgoing;
		private final SocketChannel channel;
		private final PrintWriter writer;

		public SendButtonListener(JTextField outgoingMessage, SocketChannel channel) {
		public SendButtonListener(JTextField outgoingMessage, Socket socket) {
		try {
		writer = new PrintWriter(socket.getOutputStream());
		} catch (IOException e) {
		throw new RuntimeException(e);
		}
		outgoing = outgoingMessage;
		this.channel = channel;
		}

		public void actionPerformed(ActionEvent ev) {
		// pretty sure this is doing what I think it's doing
		byte[] message = outgoing.getText().getBytes();
		ByteBuffer buffer = ByteBuffer.wrap(message);
		try {
		channel.write(buffer);
		writer.println(outgoing.getText());
		writer.flush();
		} catch (Exception ex) {
		ex.printStackTrace();
		}
		@@ -87,12 +88,12 @@ class ClientUI {
		}

		class IncomingReader implements Runnable {
		private final SocketChannel channel;
		private final BufferedReader reader;
		private final JTextArea incomingMessageArea;

		public IncomingReader(JTextArea incomingMessageArea, SocketChannel channel) {
		public IncomingReader(JTextArea incomingMessageArea, Socket socket) throws IOException {
		this.incomingMessageArea = incomingMessageArea;
		this.channel = channel;
		reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
		}

		public void run() {
		@@ -100,18 +101,12 @@ class IncomingReader implements Runnable {
		}

		private void processMessages() {
		ByteBuffer buffer = ByteBuffer.allocate(80);

		String message;
		try {
		while (channel.read(buffer) != -1) {
		buffer.flip();
		CharBuffer message = StandardCharsets.UTF_8.decode(buffer);
		while ((message = reader.readLine()) != null) {
		System.out.println("read " + message);
		incomingMessageArea.append(message + "\n");
		buffer.clear();
		}
		channel.close();
		System.out.println("Connection closed");
		} // close while
		} catch (Exception ex) {
		ex.printStackTrace();
		}

src/main/java/ch15/SimpleChatServer.java

+29 −41

Changes for src/main/java/ch15/SimpleChatServer.java: 29 added lines, 41 removed lines.
Original line number	Diff line number	Diff line
		package ch15;

		import java.io.BufferedReader;
		import java.io.IOException;
		import java.net.InetSocketAddress;
		import java.nio.ByteBuffer;
		import java.nio.channels.ServerSocketChannel;
		import java.nio.channels.SocketChannel;
		import java.io.InputStreamReader;
		import java.io.PrintWriter;
		import java.net.ServerSocket;
		import java.net.Socket;
		import java.util.ArrayList;
		import java.util.Iterator;
		import java.util.concurrent.ExecutorService;
		import java.util.concurrent.Executors;

		@@ -18,75 +20,61 @@ public class SimpleChatServer {

		public void go() {
		try {
		ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
		serverSocketChannel.bind(new InetSocketAddress("localhost", 5000));

		ServerSocket serverSock = new ServerSocket(5000);
		Broadcaster broadcaster = new Broadcaster();
		while (serverSocketChannel.isOpen()) {
		SocketChannel clientSocket = serverSocketChannel.accept();
		while (!serverSock.isClosed()) {
		Socket clientSocket = serverSock.accept();
		broadcaster.addClient(clientSocket);
		executorService.execute(new ClientHandler(clientSocket, broadcaster));
		System.out.println("got a connection");
		}
		serverSocketChannel.close();
		executorService.shutdown();
		} catch (IOException ex) {
		} catch (Exception ex) {
		ex.printStackTrace();
		}
		}
		}

		class ClientHandler implements Runnable {
		private final SocketChannel clientSocket;
		private final BufferedReader reader;
		private final Broadcaster broadcaster;

		public ClientHandler(SocketChannel clientSocket, Broadcaster broadcaster) {
		this.clientSocket = clientSocket;
		public ClientHandler(Socket clientSocket, Broadcaster broadcaster) throws IOException {
		this.broadcaster = broadcaster;
		}
		InputStreamReader isReader = new InputStreamReader(clientSocket.getInputStream());
		reader = new BufferedReader(isReader);
		} // close constructor

		public void run() {
		ByteBuffer buffer = ByteBuffer.allocate(80);
		String message;
		try {
		while (clientSocket.read(buffer) != -1) {
		buffer.flip();
		broadcaster.tellEveryone(buffer);
		buffer.clear();
		}
		disconnectClient();
		while ((message = reader.readLine()) != null) {
		System.out.println("read " + message);
		broadcaster.tellEveryone(message);
		} // close while
		} catch (Exception ex) {
		ex.printStackTrace();
		}
		}

		private void disconnectClient() throws IOException {
		clientSocket.close();
		System.out.println("Closed: " + clientSocket);
		broadcaster.remove(clientSocket);
		}
		}

		class Broadcaster {
		private final ArrayList<SocketChannel> clientOutputStreams = new ArrayList<>();
		private final ArrayList<PrintWriter> clientOutputStreams = new ArrayList<>();

		void addClient(SocketChannel clientSocket) {
		clientOutputStreams.add(clientSocket);
		void addClient(Socket clientSocket) throws IOException {
		clientOutputStreams.add(new PrintWriter(clientSocket.getOutputStream()));
		}

		public void tellEveryone(ByteBuffer buffer) {
		for (SocketChannel channel : clientOutputStreams) {
		public void tellEveryone(String message) {
		Iterator<PrintWriter> it = clientOutputStreams.iterator();
		while (it.hasNext()) {
		try {
		while (buffer.hasRemaining()) {
		channel.write(buffer);
		}
		buffer.rewind();
		PrintWriter writer = it.next();
		writer.println(message);
		writer.flush();
		} catch (Exception ex) {
		ex.printStackTrace();
		}
		}
		}

		public void remove(SocketChannel clientSocket) {
		clientOutputStreams.remove(clientSocket);
		}
		}
		No newline at end of file