加载执行顺序

• handler added
• channel registered
• channel active
  requet method:GET
• channel inactive
• channel unregistered
• handler removed

服务端代码 - 模拟Web服务器请求

启动类

public class Server {
    public static void main(String[] args) throws Exception {
        EventLoopGroup boss = new NioEventLoopGroup();
        EventLoopGroup worker = new NioEventLoopGroup();

        try {
            ServerBootstrap bootstrap = new ServerBootstrap();
            bootstrap.group(boss, worker).channel(NioServerSocketChannel.class)
                    .childHandler(new ServerInitializer());
            ChannelFuture future = bootstrap.bind(8888).sync();
            future.channel().closeFuture().sync();
        } finally {
            boss.shutdownGracefully();
            worker.shutdownGracefully();
        }
    }
}

ChannelInitializer

public class ServerInitializer extends ChannelInitializer<SocketChannel> {

    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {
        ChannelPipeline pipeline = socketChannel.pipeline();
        pipeline.addLast(new HttpServerCodec());
        pipeline.addLast(new HttpServerHandler());
    }

ChannelHandler

public class HttpServerHandler extends SimpleChannelInboundHandler<HttpObject> {
    
@Override
    public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channel registered");
        super.channelRegistered(ctx);
    }

    @Override
    public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channel unregistered");
        super.channelUnregistered(ctx);
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channel active");
        super.channelActive(ctx);
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channel inactive");
        super.channelInactive(ctx);
    }

    @Override
    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        System.out.println("handler added");
        super.handlerAdded(ctx);
    }

    @Override
    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
        System.out.println("handler removed");
        super.handlerRemoved(ctx);
    }

@Override
    protected void channelRead0(ChannelHandlerContext channelHandlerContext, HttpObject httpObject) throws Exception {

        System.out.println(channelHandlerContext.channel().remoteAddress());
        Thread.sleep(10000);//可以查看端口号
        if (httpObject instanceof HttpRequest) {
            HttpRequest httpRequest = (HttpRequest) httpObject;
            System.out.println("request method: " + httpRequest.method().name());

            URI uri = new URI(httpRequest.uri());
            if("favicon.ico".equals(uri.getPath())){
                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());

            channelHandlerContext.writeAndFlush(response);
        }

    }
}

lsof -i:8888 查看客户端端口