案例要求

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Server
  1. public class Server {
  2.     public static void main(String[] args) throws Exception {
  3.         EventLoopGroup bossGroup = new NioEventLoopGroup(1);
  4.         EventLoopGroup workerGroup = new NioEventLoopGroup();
  6.         try {
  7.             ServerBootstrap serverBootstrap = new ServerBootstrap();
  8.             serverBootstrap.group(bossGroup, workerGroup)
  9.                     .channel(NioServerSocketChannel.class)
  10.                     .childHandler(new ServerInitializer());
  12.             //绑定端口
  13.             ChannelFuture channelFuture = serverBootstrap.bind(8081).sync();
  14.             channelFuture.channel().closeFuture().sync();
  16.         } finally {
  17.             bossGroup.shutdownGracefully();
  18.             workerGroup.shutdownGracefully();
  19.         }
  20.     }
  21. }

ServerHandler
  1. /*
  2. 1.SimpleChannelInboundHandler是ChannelInboundHandlerAdapter的子类
  3. 2.HttpObject表示客户端和服务器端相互通讯的数据被封装成 HttpObject对象
  4.  */
  5. public class ServerHandler extends SimpleChannelInboundHandler<HttpObject> {
  6.     //读取客户端数据
  7.     @Override
  8.     protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
  9.         //判断msg是不是HttpRequest请求
  10.         if (msg instanceof HttpRequest) {
  12.             System.out.println("msg的类型" + msg.getClass());
  13.             System.out.println("客户端地址" + ctx.channel().remoteAddress());
  15.             //过滤掉特定资源
  16.             HttpRequest httpRequest = (HttpRequest) msg;
  17.             //获取uri
  18.             URI uri = new URI(httpRequest.uri());
  19.             if ("/favicon.ico".equals(uri.getPath())) {
  20.                 System.out.println("请求了favicon.ico图标，但是不进行响应");
  21.                 return;
  22.             }
  24.             //回复信息给浏览器 【Http协议】
  25.             ByteBuf content = Unpooled.copiedBuffer("hello，我是服务器", StandardCharsets.UTF_16);
  27.             //构造Http响应 即HttpResponse--指定http版本和状态码
  28.             FullHttpResponse response =
  29.                     new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, content);
  30.             response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain");
  31.             response.headers().set(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());
  33.             //将构建好的response返回
  34.             ctx.writeAndFlush(response);
  35.         }
  36.     }
  37. }

ServerInitializer
  1. public class ServerInitializer extends ChannelInitializer<SocketChannel> {
  2.     @Override
  3.     protected void initChannel(SocketChannel ch) throws Exception {
  4.         //加入处理器
  5.         //得到pipeline
  6.         ChannelPipeline pipeline = ch.pipeline();
  8.         //加入Netty提供的HttpServerCodec  编解码器
  9.         pipeline.addLast("MyHttpServerCodec", new HttpServerCodec());
  10.         //加入自定义处理器
  11.         pipeline.addLast("MyServerHandler", new ServerHandler());
  12.     }
  13. }

效果

image.png

注意点

1.http服务器的时候，ServerBootStrap在bind端口之后，可能收不到浏览器请求，可能是由于某些端口(6665-6669等)是浏览器的默认非安全端口，浏览器给拦截了
2.需要对某些资源请求设置不进行访问，比如浏览器页面的小图标
3.不同的浏览器来请求对应着各自的handler，并不是使用同一个，因为HTTP不是长连接，所有刷新一个页面也会再次分配一个新的handler
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