//启动类
    public class MainServer {
        public static void main(String[] args) throws Exception {
            ServerBootstrap bootstrap = new ServerBootstrap();    // 创建Server-Bootstrap
            bootstrap.group(new NioEventLoopGroup()) // 创建Event-LoopGroup
                    .channel(NioServerSocketChannel.class) //指定所使用的NIO传输Channel
                    .childHandler(new ChannelInitializer(){
                        //我们平时会在这里添加处理数据协议, Netty会将add进去的Handler从上到下依次执行
                        @Override
                        protected void initChannel(Channel ch) throws Exception {
                            ch.pipeline().addLast(new HttpServerCodec());//Netty实现的 HTTP协议处理器
                            ch.pipeline().addLast(new HelloworldHandler()); //EchoServerHandler被标注为@Shareable，所以我们可以总是使用同样的实例
                        }
                    });
            ChannelFuture f = bootstrap.bind(8080).sync();  //异步地绑定服务器；调用sync()方法阻塞等待直到绑定完成
            f.channel().closeFuture().sync();//获取Channel的CloseFuture，并且阻塞当前线程直到它完成
        }
    }
    
     //业务处理器类
    public class HelloworldHandler extends SimpleChannelInboundHandler<HttpObject> {
            @Override
            protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
                System.out.println("Server received: " + msg);//请求数据
                if (msg instanceof HttpRequest) {
                    HttpRequest request = (HttpRequest) msg;
                    FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
                    response.content().writeBytes("hello word".getBytes());
                    response.headers().set("Content-Type", "text/plain");
                    response.headers().setInt("Content-Length", response.content().readableBytes());
    
                    if (HttpUtil.isKeepAlive(request)) {
                        response.headers().set("Connection", "keep-alive");
                        ctx.writeAndFlush(response);
                    } else {
                        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
                    }
                }
            }
        }