Netty書籍推薦

一、Netty是什麼

Netty是一個高性能、異步的NIO框架，基於Java NIO的特性進行封裝。它的出現，使得基於NIO的開發變得更加簡單，同時提高了性能和可靠性。在我們學習Netty之前，推薦閱讀以下兩本書籍：

二、《Netty權威指南》

《Netty權威指南》通俗易懂，適合入門學習。這本書旨在為使用Netty框架的開發人員提供一個全面的、深入的指南，涵蓋了網絡協議、異步編程和Netty API的所有方面。這本書分為七個部分，其中包括：Netty的架構和工作原理、Netty的基本組件和功能、網絡協議的實現、數據處理、安全性、優化和擴展。下面是一個簡單的Netty服務端的示例：

public class NettyServer {

    public static void main(String[] args) throws InterruptedException {
        NioEventLoopGroup bossGroup = new NioEventLoopGroup(1);
        NioEventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .option(ChannelOption.SO_BACKLOG, 128)
                    .childOption(ChannelOption.SO_KEEPALIVE, true)
                    .childHandler(new ChannelInitializer() {
                        @Override
                        public void initChannel(SocketChannel ch) throws Exception {
                            ChannelPipeline pipeline = ch.pipeline();
                            pipeline.addLast(new StringDecoder());
                            pipeline.addLast(new StringEncoder());
                            pipeline.addLast(new NettyServerHandler());
                        }
                    });

            ChannelFuture channelFuture = serverBootstrap.bind(6668).sync();

            channelFuture.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

class NettyServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        System.out.println((String) msg);
        ctx.writeAndFlush("服務端已接收到消息");
    }
}

三、《深入分析Java Web技術內幕》

《深入分析Java Web技術內幕》是一本從Java基礎知識到實際應用場景的詳細闡述之書。在裡面，關於Netty的介紹並不是非常詳細，但是對於理解網絡原理和協議處理有着重要的幫助。如果你在使用Netty過程中，遇到了一些網絡協議的問題，這本書會給你提供新的思路。下面是一個簡單的HTTP服務端的示例：

public class HttpServer {

    public static void main(String[] args) throws InterruptedException {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap()
                    .group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new ChannelInitializer() {
                        @Override
                        public void initChannel(SocketChannel ch) throws Exception {
                            ChannelPipeline pipeline = ch.pipeline();
                            pipeline.addLast(new HttpServerCodec());
                            pipeline.addLast(new HttpObjectAggregator(1024 * 1024));
                            pipeline.addLast(new HttpServerHandler());
                        }
                    });
            ChannelFuture channelFuture = serverBootstrap.bind(8888).sync();
            channelFuture.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

class HttpServerHandler extends SimpleChannelInboundHandler {
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest msg) throws Exception {
        System.out.println(msg.toString());
        ByteBuf content = Unpooled.copiedBuffer("服務端已接收到消息", CharsetUtil.UTF_8);
        FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, content);
        response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain");
        response.headers().set(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());
        ctx.writeAndFlush(response);
    }
}

四、《Netty實戰》

《Netty實戰》是一個循序漸進的指南，適合開發人員逐步掌握Netty框架，並在實際應用中使用。該書覆蓋了Netty網絡編程的所有不同方面，包括：使用ByteBuf進行編解碼、使用ChannelHandler實現協議處理、使用EventLoop執行異步I/O操作以及使用Netty構建客戶端和服務端。下面是一個簡單的Netty客戶端的示例：

public class NettyClient {

    public static void main(String[] args) throws Exception {
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(group)
                    .channel(NioSocketChannel.class)
                    .handler(new ChannelInitializer() {
                        @Override
                        public void initChannel(SocketChannel ch) throws Exception {
                            ChannelPipeline pipeline = ch.pipeline();
                            pipeline.addLast(new StringDecoder());
                            pipeline.addLast(new StringEncoder());
                            pipeline.addLast(new NettyClientHandler());
                        }
                    });
            ChannelFuture channelFuture = bootstrap.connect("127.0.0.1", 6668).sync();
            channelFuture.channel().closeFuture().sync();
        } finally {
            group.shutdownGracefully();
        }
    }
}

class NettyClientHandler extends SimpleChannelInboundHandler {
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        ctx.writeAndFlush("客戶端發送消息");
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
        System.out.println(msg);
    }
}