三种TCP协议聊天室实现
一 概述
- 使用Java的IO实现聊天室
- 使用Java的NIO实现聊天室
- 使用Netty实现聊天室
二 IO聊天室
1 服务器
public class IOServer {
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = new ServerSocket();
serverSocket.setReuseAddress(true);
serverSocket.bind(new InetSocketAddress(8899));
ExecutorService executor = Executors.newCachedThreadPool();
Set<Socket> socketGroup = new HashSet<>();
while (true) {
Socket socket = serverSocket.accept();
socketGroup.add(socket);
executor.execute(() -> {
try (
InputStream in = socket.getInputStream();
InputStreamReader reader = new InputStreamReader(in, "UTF-8");
BufferedReader br = new BufferedReader(reader);
) {
String line;
while ((line = br.readLine()) != null) {
int port = socket.getPort();
System.out.println("from client:{" + port + "}" + line);
String finalLine = line;
for (Socket client : socketGroup) {
if (client == socket) continue;
try {
OutputStream output = client.getOutputStream();
DataOutputStream out = new DataOutputStream(output);
String s = "client{" + port + "}" + finalLine + "\n";
out.write(s.getBytes());
} catch (IOException e) {
e.printStackTrace();
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
});
}
}
}
2 客户端
public class IOClient {
public static void main(String[] args) throws IOException {
Socket socket = new Socket();
InetSocketAddress address = new InetSocketAddress("localhost", 8899);
socket.connect(address);
try (
OutputStream output = socket.getOutputStream();
DataOutputStream out = new DataOutputStream(output);
Reader rd = new InputStreamReader(socket.getInputStream());
BufferedReader bufferRd = new BufferedReader(rd);
) {
// 子线程监听输入并发送
new Thread(() -> {
InputStreamReader in = new InputStreamReader(System.in);
BufferedReader reader = new BufferedReader(in);
while (true) {
try {
out.write((reader.readLine() + '\n').getBytes());
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
// 主线程循环监听接受到的数据并输出
while (true) {
System.out.println(bufferRd.readLine());
}
}
}
}
三 NIO聊天室
1 服务器
public class NIOServer {
public static void main(String[] args) throws IOException {
ServerSocketChannel srvSocketChannel = ServerSocketChannel.open();
srvSocketChannel.configureBlocking(false);
ServerSocket socket = srvSocketChannel.socket();
socket.setReuseAddress(true);
socket.bind(new InetSocketAddress(8899));
Selector selector = Selector.open();
srvSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
Set<SocketChannel> channelGroup = new HashSet<>();
while (selector.select() > 0) {
Set<SelectionKey> keys = selector.selectedKeys();
for (SelectionKey key : keys) {
SocketChannel client;
if (key.isAcceptable()) {
ServerSocketChannel channel = (ServerSocketChannel) key.channel();
client = channel.accept();
client.configureBlocking(false);
client.register(selector, SelectionKey.OP_READ);
channelGroup.add(client);
System.out.println(client.getRemoteAddress());
} else if (key.isReadable()) {
client = (SocketChannel) key.channel();
ByteBuffer buffer = ByteBuffer.allocate(1024);
client.read(buffer);
buffer.flip();
System.out.print(new String(buffer.array()));
channelGroup.forEach(channel -> {
buffer.rewind();
if (channel != client) {
try {
int port = client.socket().getPort();
byte[] array = buffer.array();
String s = "client{" + port + "}:" + new String(array);
channel.write(ByteBuffer.wrap(s.getBytes()));
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
keys.remove(key);
}
}
}
}
2 客户端
public class NIOClient {
public static void main(String[] args) throws IOException {
SocketChannel socketChannel = SocketChannel.open();
socketChannel.configureBlocking(false);
InetSocketAddress address = new InetSocketAddress("localhost", 8899);
socketChannel.connect(address);
Selector selector = Selector.open();
socketChannel.register(selector, SelectionKey.OP_CONNECT);
while (selector.select() > 0) {
Set<SelectionKey> keys = selector.selectedKeys();
for (SelectionKey key : keys) {
SocketChannel client;
if (key.isConnectable()) {
client = (SocketChannel) key.channel();
if (client.isConnectionPending()) {
client.finishConnect();
client.register(selector, SelectionKey.OP_READ);
new Thread(() -> {
InputStreamReader in = new InputStreamReader(System.in);
BufferedReader reader = new BufferedReader(in);
while (true) {
try {
String line = reader.readLine() + '\n';
client.write(ByteBuffer.wrap(line.getBytes()));
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
} else if (key.isReadable()) {
client = (SocketChannel) key.channel();
ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
client.read(byteBuffer);
byteBuffer.flip();
while (byteBuffer.hasRemaining()) {
System.out.print((char)byteBuffer.get());
}
}
keys.remove(key);
}
}
}
}
四 Netty聊天室
1 服务器
- TCPServer.java
public class TCPServer {
public static void main(String[] args) throws InterruptedException {
EventLoopGroup boss = new NioEventLoopGroup();
EventLoopGroup worker = new NioEventLoopGroup();
try {
ServerBootstrap bootstrap = new ServerBootstrap();
bootstrap.group(boss,worker).channel(NioServerSocketChannel.class)
.handler(new LoggingHandler(LogLevel.INFO))
.childHandler(new ServerChannelInitializer());
ChannelFuture channelFuture = bootstrap.bind(8899).sync();
channelFuture.channel().closeFuture().sync();
} finally {
boss.shutdownGracefully();
worker.shutdownGracefully();
}
}
}
- ServerChannelInitializer.java
public class ServerChannelInitializer extends ChannelInitializer<SocketChannel> {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast(new DelimiterBasedFrameDecoder(4096,Delimiters.lineDelimiter()));
pipeline.addLast(new StringDecoder(UTF_8));
pipeline.addLast(new StringEncoder(UTF_8));
pipeline.addLast(new ServerHandler());
}
}
- ServerHandler.java
public class ServerHandler extends SimpleChannelInboundHandler<String> {
private static ChannelGroup group = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
@Override
public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
Channel channel = ctx.channel();
group.forEach(ch -> {
ch.writeAndFlush(channel.remoteAddress() + " 上线" + "\n");
});
group.add(channel);
}
@Override
public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
group.forEach(ch -> {
ch.writeAndFlush(ctx.channel().remoteAddress() + " 下线" + "\n");
});
}
@Override
protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
Channel channel = ctx.channel();
group.forEach(ch -> {
if (ch != channel) {
ch.writeAndFlush(channel.remoteAddress() + ":" + msg + "\n");
} else {
ch.writeAndFlush("自己:" + msg + "\n");
}
});
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
ctx.close();
}
}
2 客户端
- TCPClient.java
public class TCPClient {
public static void main(String[] args) throws InterruptedException, IOException {
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap bootstrap = new Bootstrap();
bootstrap.group(group)
.channel(NioSocketChannel.class)
.handler(new ClientChannelInitializer());
Channel channel = bootstrap
.connect("localhost", 8899)
.sync()
.channel();
InputStreamReader in = new InputStreamReader(System.in);
BufferedReader reader = new BufferedReader(in);
while (true) {
channel.writeAndFlush(reader.readLine() + "\n");
}
} finally {
group.shutdownGracefully();
}
}
}
- ClientChannelInitializer.java
public class ClientChannelInitializer extends ChannelInitializer<SocketChannel> {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast(new DelimiterBasedFrameDecoder(4096, Delimiters.lineDelimiter()));
pipeline.addLast(new StringDecoder(UTF_8));
pipeline.addLast(new StringEncoder(UTF_8));
pipeline.addLast(new SimpleChannelInboundHandler<String>() {
@Override
protected void channelRead0(ChannelHandlerContext ctx, String msg) {
System.out.println(msg);
}
});
}
}
五 总结
- Netty实现简单，逻辑清晰，但是隐藏了很多复杂的细节，后续的学习再慢慢剖析吧。
- IO的线程模型，实现比较通俗易懂。
- NIO的实现相对比较难懂，需要大家对Selector、Channel和Buffer有比较深刻的理解，不然很容易出错。
注：NIO是Netty的基础，学好NIO对于Netty的学习有重要作用。
