HTTP服务实例

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public class TestServer {
    public static void main(String[] args) throws InterruptedException {
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup(8);
        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workerGroup) // 设置两个线程组
                    .channel(NioServerSocketChannel.class) // 设置 NioSctpServerChannel 作为服务器的通道实现
                    .childHandler(new TestServerInitializer()); // 给我们的 workGroup 的 EventLoop 对应的管道设置处理器
            ChannelFuture channelFuture = serverBootstrap.bind(7100).sync();
            channelFuture.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

public class TestServerInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        // 向管道加入处理器
        // 得到管道
        ChannelPipeline pipeline = ch.pipeline();
        // 加入一个 netty 提供的 httpServerCodec codec - [coder - decoder]
        // HttpServerCodec 说明
        // 1. HttpServerCodec 是 netty 提供的处理 http 的 编解码器
        pipeline.addLast("MyHttpServerCodec", new HttpServerCodec());
        // 2. 增加一个自定义的 handler
        pipeline.addLast("MyTestHttpServerHandler", new TestHttpServerHandler());
    }
}

/**
 * 1. SimpleChannelInboundHandler 是 ChannelInboundHandlerAdapter 子类
 * 2. HttpObject 客户端和服务器端相互通讯的数据被封装成 HttpObject
 */
public class TestHttpServerHandler extends SimpleChannelInboundHandler<HttpObject> {
    // 读取客户端数据
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
        // 判断 msg 是不是 httpRequest 请求
        if (msg instanceof HttpRequest) {
            System.out.println("pipeline hashcode：" + ctx.pipeline().hashCode());
            System.out.println("TestHttpServerHandler hashcode：" + this.hashCode());
            System.out.println("msg 类型 = " + msg.getClass());
            System.out.println("客户端地址：" + ctx.channel().remoteAddress());
            // 获取到
            HttpRequest httpRequest = (HttpRequest) msg;
            // 获取 uri
            URI uri = new URI(httpRequest.uri());
            if ("/favicon.ico".equals(uri.getPath())) {
                System.out.println("请求了 favicon.ico, 不做响应");
                return;
            }
            // 回复信息给浏览器 [http 协议]
            ByteBuf content = Unpooled.copiedBuffer("hello, 我是服务器", CharsetUtil.UTF_8);
            // 构造一个 http 的响应，即 httpResponse
            DefaultFullHttpResponse 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());
            // 将构建好的 response 返回
            ctx.writeAndFlush(response);
        }
    }
}