引导

EventLoopGroup group = new NioEventLoopGroup();
Bootstrap bootstrap = new Bootstrap(); //1 创建一个新的 Bootstrap 来创建和连接到新的客户端管道
bootstrap.group(group) //2 指定 EventLoopGroup
.channel(NioSocketChannel.class) //3 指定 Channel 实现来使用
.handler(new SimpleChannelInboundHandler<ByteBuf>() { //4 设置处理器给 Channel 的事件和数据
        @Override
        protected void channeRead0(
            ChannelHandlerContext channelHandlerContext,
            ByteBuf byteBuf) throws Exception {
            System.out.println("Received data");
            byteBuf.clear();
        }
    });
ChannelFuture future = bootstrap.connect(
    new InetSocketAddress("www.manning.com", 80)); //5 连接到远端主机
future.addListener(new ChannelFutureListener() {
        @Override
        public void operationComplete(ChannelFuture channelFuture)
            throws Exception {
            if (channelFuture.isSuccess()) {
                System.out.println("Connection established");
            } else {
                System.err.println("Connection attempt failed");
                channelFuture.cause().printStackTrace();
            }
        }
    });

EventLoopGroup group = new NioEventLoopGroup();
Bootstrap bootstrap = new Bootstrap(); //1 创建新的 Bootstrap 来创建新的客户端管道
bootstrap.group(group) //2 注册 EventLoopGroup 用于获取 EventLoop
.channel(OioSocketChannel.class) //3 指定要使用的 Channel 类。通知我们使用 NIO 版本用于 EventLoopGroup ， OIO 用于 Channel
.handler(new SimpleChannelInboundHandler<ByteBuf>() { //4 设置处理器用于管道的 I/O 事件和数据
                @Override
                protected void channelRead0(
                        ChannelHandlerContext channelHandlerContext,
                        ByteBuf byteBuf) throws Exception {
                        System.out.println("Reveived data");
                        byteBuf.clear();
                }
        });
ChannelFuture future = bootstrap.connect(
        new InetSocketAddress("www.manning.com", 80)); //5 尝试连接到远端。当 NioEventLoopGroup 和 OioSocketChannel 不兼容时，会抛出 IllegalStateException 异常
future.syncUninterruptibly();

ServerBootstrap bootstrap = new ServerBootstrap(); //1 创建一个新的 ServerBootstrap 来创建新的 SocketChannel 管道并且绑定他们
bootstrap.group(new NioEventLoopGroup(), //2 指定 EventLoopGroups 从 ServerChannel 和接收到的管道来注册并获取 EventLoops 
        new NioEventLoopGroup()).channel(NioServerSocketChannel.class) //3指定 Channel 类来使用
.childHandler(        //4 设置处理器用于处理接收到的管道的 I/O 和数据
    new SimpleChannelInboundHandler<ByteBuf>() {
        ChannelFuture connectFuture;

        @Override
        public void channelActive(ChannelHandlerContext ctx) throws Exception {
            Bootstrap bootstrap = new Bootstrap(); //5 创建一个新的 Bootstrap 来连接到远程主机
            bootstrap.channel(NioSocketChannel.class) //6 设置管道类
                .handler(new SimpleChannelInboundHandler<ByteBuf>() {  //7 设置处理器来处理 I/O
                        @Override
                        protected void channelRead0(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
                            System.out.println("Reveived data");
                        }
                    });
            bootstrap.group(ctx.channel().eventLoop()); //8 使用相同的 EventLoop 作为分配到接收的管道
            connectFuture = bootstrap.connect(new InetSocketAddress("www.manning.com", 80));  //9 连接到远端
        }

        @Override
        protected void channelRead0(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf) throws Exception {
            if (connectFuture.isDone()) {
                // do something with the data  //10 连接完成处理业务逻辑 (比如, proxy)
            }
        }
    });
ChannelFuture future = bootstrap.bind(new InetSocketAddress(8080));  //11 通过配置了的 Bootstrap 来绑定到管道
future.addListener(new ChannelFutureListener() {
        @Override
        public void operationComplete(ChannelFuture channelFuture) throws Exception {
            if (channelFuture.isSuccess()) {
                System.out.println("Server bound");
            } else {
                System.err.println("Bound attempt failed");
                channelFuture.cause().printStackTrace();
            }
        }
    });