Netty(4)同一TCP会话中的客户端服务器通信

Question

    String host = "localhost";
    int port = 9884;
    EventLoopGroup workerGroup = new NioEventLoopGroup();

    try {
        Bootstrap b = new Bootstrap();
        b.group(workerGroup);
        b.channel(NioSocketChannel.class);
        b.option(ChannelOption.SO_KEEPALIVE, true);
        b.handler(new MyChannelPipeline());

        // Start the client.
        ChannelFuture f = b.connect(host, port).sync();

        String line = "line";
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        while (!line.equals("exit")) {
            line = in.readLine();
            if (line == null) {
                break;
            }
        }

        // Wait until the connection is closed.
        f.channel().closeFuture().sync();

    } finally {
        workerGroup.shutdownGracefully();
    }

管道管道：

    @Override
public void initChannel(Channel ch) throws Exception {

    ChannelPipeline channelPipeline = ch.pipeline();

    //Encodes every request send from the client to the server
    channelPipeline.addLast("clientRequestEncoder", new ClientRequestEncoder());

    //Implements channelActive and exceptionCaught
    channelPipeline.addLast("initialRequestHandler", new InitialRequestHandler());

    channelPipeline.addLast("byteArrayDecoder", new ByteArrayDecoder());

    channelPipeline.addLast("serverResponseDecoder", new ServerResponseDecoder());
    channelPipeline.addLast("serverRequestDecoder", new ServerRequestDecoder());

    //Reads the responses from the client requests AND
    //reads the inbound requests from the server - Implements channelRead 
    //and exceptionCaught
    channelPipeline.addLast("myResponseHandler", new MyResponseHandler());


}

问题是，当我将响应刷新到服务器（在MyResponseHandler中）时，会在InitialRequestHandler中捕获exception：

error=java.lang.UnsupportedOperationException：不受支持的消息类型：ServerResponse（应为：ByteBuf,FileRegion）

我不明白为什么响应不被刷新回服务器，而握手请求总是被正确刷新。在write和flush中，我都使用了ChannelFuture和onOperationComplete这个监听器f.addListener(channelFutureListener.fire_exception_on_failure)；在失败时触发。

我可以在同一个管道中使用两个处理程序吗？此外，我应该如何激发由用户输入触发的取消注册事件？

Answer 1

我使用一个覆盖channelActive和channelRead的处理程序解决了这个问题，并正确地重新安排了编码器和解码器。我还这样解决了“用户输入触发的注销事件”：

    String line = "line";
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    do {
        logger.info("You typed: " + line + ". Please type 'exit' to terminate the program!");
        line = in.readLine();
    } while (!line.equals("exit"));
    logger.info("You typed: " + line + ". Please wait until the application is successfully shutdown...");

    f.addListener(new ChannelFutureListener() {
        public void operationComplete(ChannelFuture future) throws Exception {
            myChannelPipeline.getMyClientHandler().sendDisconnectRequest(future);
        }
    });

在sendDisconnectReqeust中，我发送最后一个请求，当我得到最后一个响应（在MyHandler的channelRead中）时，我在管道上调用disconnect：

    ChannelPromise cp = new DefaultChannelPromise(ctx.channel());
    ctx.channel().pipeline().disconnect(cp);

然而，我仍然有其他问题的入站请求，从来没有收到我的客户。