从零手写实现 nginx-03-nginx 基于 Netty 实现

/**
 * netty 实现
 * 
 * @author 老马啸西风
 * @since 0.2.0
 */
public class NginxServerNetty implements INginxServer {

    private static final Log log = LogFactory.getLog(NginxServerNetty.class);


    private NginxConfig nginxConfig;

    @Override
    public void init(NginxConfig nginxConfig) {
        this.nginxConfig = nginxConfig;
    }

    @Override
    public void start() {
        // 服务器监听的端口号
        String host = InnerNetUtil.getHost();
        int port = nginxConfig.getHttpServerListen();

        EventLoopGroup bossGroup = new NioEventLoopGroup();
        //worker 线程池的数量默认为 CPU 核心数的两倍
        EventLoopGroup workerGroup = new NioEventLoopGroup();

        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline().addLast(new NginxNettyServerHandler(nginxConfig));
                        }
                    })
                    .option(ChannelOption.SO_BACKLOG, 128)
                    .childOption(ChannelOption.SO_KEEPALIVE, true);

            // Bind and start to accept incoming connections.
            ChannelFuture future = serverBootstrap.bind(port).sync();

            log.info("[Nginx4j] listen on http://{}:{}", host, port);

            // Wait until the server socket is closed.
            future.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            log.error("[Nginx4j] start meet ex", e);
            throw new Nginx4jException(e);
        } finally {
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();

            log.info("[Nginx4j] shutdownGracefully", host, port);
        }
    }

}

处理类

核心的处理逻辑都在 NginxNettyServerHandler 这个类。

这里主要做 3 件事

解析请求类
根据请求获取对应的内容
返回响应内容

java 复制代码

/**
 * netty 处理类
 * @author 老马啸西风
 * @since 0.2.0
 */
public class NginxNettyServerHandler extends ChannelInboundHandlerAdapter {

    private static final Log logger = LogFactory.getLog(NginxNettyServerHandler.class);

    private final NginxConfig nginxConfig;

    public NginxNettyServerHandler(NginxConfig nginxConfig) {
        this.nginxConfig = nginxConfig;
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf buf = (ByteBuf) msg;
        byte[] bytes = new byte[buf.readableBytes()];
        buf.readBytes(bytes);
        String requestString = new String(bytes, nginxConfig.getCharset());
        logger.info("[Nginx] channelRead requestString={}", requestString);

        // 请求体
        final NginxRequestConvertor requestConvertor = nginxConfig.getNginxRequestConvertor();
        NginxRequestInfoBo nginxRequestInfoBo = requestConvertor.convert(requestString, nginxConfig);

        // 分发
        final NginxRequestDispatch requestDispatch = nginxConfig.getNginxRequestDispatch();
        String respText = requestDispatch.dispatch(nginxRequestInfoBo, nginxConfig);

        // 结果响应
        ByteBuf responseBuf = Unpooled.copiedBuffer(respText.getBytes());
        ctx.writeAndFlush(responseBuf)
                .addListener(ChannelFutureListener.CLOSE); // Close the channel after sending the response
        logger.info("[Nginx] channelRead writeAndFlush DONE");
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        logger.error("[Nginx] exceptionCaught", cause);
        ctx.close();
    }

}

其中请求的解析为对象，便于后续开发中使用。

分发处理只是加了一层抽象，整体实现和上一节类似。

感兴趣可以阅读源码。

小结

本节我们使用 netty 大幅度提升一下响应性能。

到这里我们实现了一个简单的 http 服务器，当然这是远远不够的。

后续我们会继续一起实现更多的 nginx 特性。

我是老马，期待与你的下次重逢。

开源地址

为了便于大家学习，已经将 nginx 开源

https://github.com/houbb/nginx4j