1、Netty与Http的实现关键类摘要Netty不是遵循Http的Servlet标准规范进行实现，是优质的http实现HttpServerCodec是一个编码处理器，用于管道时间监听.FullHttpResponse对象是设置http协议，header请求头属性favicon.ico当浏览器进行发送请求的时候，会去根目录进行查找Netty没有提供路由，需要开发者自己实现，它也没有完善的Http支持，也有开发设计者决定

FullHttpResponse关系图

HttpServerCodec关系图

2、Netty的Channel通道Channel通道类似是拦截器（ChannelPipeline）针对客户端的请求进行处理3、Netty的EventLoopGroup摘要EventLoopGroup其实是使用了死循环，对连接不断接收数据EventLoopGroup是一个线程组，在使用时是推荐两个EventLoopGroup，而且group方法，第一个参数是接收请求，不做任何业务处理（Reactor模型的mainReactor）。第二个参数是对要实现的对象处理，（相当于Reactor模型的subReactor）

EventLoopGroup

4、Netty的ChannelInitializer摘要ChannelInitializer 这个类表示，一旦被连接之后会注册，而且只有一个抽象方法

ChannelInitializer

5、Netty重要方法使用write方法数据会放在缓冲区，不会返回客户端响应请求，所以推荐使用writeAndFlush方法channelRead0在Netty5.0发生了改变，重命名了messageReceived方法

SimpleChannelInboundHandler

channelRead0

6、Netty设计理念Netty设计理思想对大多数线程控制7、NioServerSocketChannelNioServerSocketChannel对象内部绑定了Java NIO创建的ServerSocketChannel对象；Netty中，AbstractChannel有一个unsafe对象，此对象封装了Java NIO底层channel的操作细节；Netty中，每个channel都有一个pipeline对象，此对象就是一个双向链表；

public abstract class AbstractNioMessageChannel extends AbstractNioChannel {     @Override    protected AbstractNioUnsafe newUnsafe() {        return new NioMessageUnsafe();    }}

public class TestServer {    public static void main(String[] args) throws Exception {        //创建bossGroup        EventLoopGroup bossGroup   = new NioEventLoopGroup();        //创建workerGroup        EventLoopGroup workerGroup = new NioEventLoopGroup();        try {            //创建ServerBootstrap            ServerBootstrap serverBootstrap = new ServerBootstrap();            serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).childHandler(new TestServerInitializer());            //绑定端口            ChannelFuture channelFuture = serverBootstrap.bind(8080).sync();            //同步            channelFuture.channel().closeFuture().sync();        } finally {            //优雅关闭            bossGroup.shutdownGracefully();            workerGroup.shutdownGracefully();        }    }}

public class TestHttpServerHandler extends SimpleChannelInboundHandler<HttpObject> {    @Override    protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {        System.out.println(msg.getClass());        System.out.println(ctx.channel().remoteAddress());        if (msg instanceof HttpRequest) {            HttpRequest httpRequest = (HttpRequest)msg;            System.out.println("请求方法名：" + httpRequest.method().name());            URI uri = new URI(httpRequest.uri());            if("/favicon.ico".equals(uri.getPath())) {                System.out.println("请求favicon.ico");                return;            }            ByteBuf content = Unpooled.copiedBuffer("Hello World", 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);            ctx.channel().close();        }    }    @Override    public void channelActive(ChannelHandlerContext ctx) throws Exception {        System.out.println("channel active");        super.channelActive(ctx);    }    @Override    public void channelRegistered(ChannelHandlerContext ctx) throws Exception {        System.out.println("channel registered");        super.channelRegistered(ctx);    }    @Override    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {        System.out.println("handler added");        super.handlerAdded(ctx);    }    @Override    public void channelInactive(ChannelHandlerContext ctx) throws Exception {        System.out.println("channel inactive");        super.channelInactive(ctx);    }    @Override    public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {        System.out.println("channel unregistered");        super.channelUnregistered(ctx);    }}

public class TestServerInitializer extends ChannelInitializer<SocketChannel>{    @Override    protected void initChannel(SocketChannel ch) throws Exception {        ChannelPipeline pipeline = ch.pipeline();        pipeline.addLast("httpServerCodec", new HttpServerCodec());        pipeline.addLast("testHttpServerHandler", new TestHttpServerHandler());    }}