1、Netty的Handler模型

2、服务端代码示例

根据模型图可以更好的理解ServerBootstrap引导类设置Netty的属性。

public class TimeServer {
    private int port;
    public TimeServer(int port) {
        this.port = port;
    }
    public void run() throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup,workGroup)
                    //设置使用的使用的Channel类
                    .channel(NioServerSocketChannel.class)
                    //设置NioServerSocketChannel的Pipeline的Handler
                    .handler(null)
                    // 用于设置ServerChannel的选项，如：NioServerSocketChanne，来监听和接收connection。作用于当bind() 时。
                    .option(ChannelOption.SO_BACKLOG, 128)
                    //设置NioServerSocketChannel 附带的属性
                    //.attr()
                    //用于设置SocketChannel，作用于connection成功后channel的I/O操作。
                    .childOption(ChannelOption.SO_KEEPALIVE, true)
                    //设置SocketChannel 附带的属性
                    //.childAttr()
                    //设置连接SocketChannel的的handler
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel socketChannel) throws Exception {
                            socketChannel.pipeline().addLast(new TimeServerHandler());
                        }
                    });
            ChannelFuture f = b.bind(port).sync();
            f.addListener((ChannelFutureListener) future -> System.out.println("服务启动完毕"));
            f.channel().closeFuture().sync();
        } finally {
          workGroup.shutdownGracefully();
          bossGroup.shutdownGracefully();
        }
    }
}