java - Netty:未使用 DefaultFileRegion 调用 ChannelProgressiveFutureListener

Question

我正在使用 DefaulfFileRegion 从基于 netty 的服务器进行下游传输。当客户端接收数据时，我添加到 channel future 的 ChannelProgressiveFutureListener 永远不会被调用。我对使用 netty 编程不太有经验，所以我想我误解了 netty 渐进式 ChannelFuture 的工作原理。因此，我查看了在这里找到的示例代码:programcreek.com 。但它的代码基本相同？我尝试在这里寻找类似的问题，但找不到原因。预先感谢您的任何提示，为什么听众永远不会被调用。

   long todo = file.length () - mRequest.pCursor;
    ctx.writeAndFlush (mFileCursorPacket.encodeInformation (new FileCursor (mRequest.pToken, todo)));


    mFileregion = new DefaultFileRegion (file, mRequest.pCursor, todo);
    ChannelFuture future = ctx.writeAndFlush (mFileregion,ctx.newProgressivePromise ());

    //the listener that is never called!
    future.addListener (new ChannelProgressiveFutureListener () {
        @Override
        public void operationProgressed (ChannelProgressiveFuture future, long progress, long total) throws Exception {
            O.debug (mSession.getId ()+": downloaded "+progress+" bytes  = "+String.valueOf ((float)progress/(float)total));
        }

        @Override
        public void operationComplete (ChannelProgressiveFuture future) throws Exception {
            boolean success = future.isSuccess ();
            O.info (mSession.getId () + ": downloaded successfull: " + success);
            if (mFileregion != null) mFileregion.release ();
            mFileregion = null;
        }
    });

我的管道如下所示:

        ServerBootstrap b = new ServerBootstrap (); // 
        b.group (mBossGroup, mWorkerGroup).channel (NioServerSocketChannel.class) // 
                //.channel(ServerSocketChannel.class)
                .childHandler (new ChannelInitializer<SocketChannel> () { // 
                    @Override
                    public void initChannel (SocketChannel ch) throws Exception {

                        ProtocolMessageInboundHandler inboundHandler = new ProtocolMessageInboundHandler ();
                        inboundHandler.setMessageSizeLimit (MAX_PACKET_LENGTH);
                        ch.pipeline ().addLast (ReadTimeoutHandler.class.getName (), new ReadTimeoutHandler (SO_TIMEOUT_STD));
                        ch.pipeline ().addLast (NAME_PROTOCOL_MESSAGE_INBOUND, inboundHandler);
                        ch.pipeline ().addLast (NAME_PROTOCOL_MESSAGE_OUTBOUND, new ProtoclMessageOutboundHandler ());

//context passed to the LoginHandler is a ServerContext and has nothing to do with netty
                        ch.pipeline ().addLast (LoginHandler.class.getName (), new LoginHandler (context));
                        ch.pipeline ().addLast (TimeoutHandler.class.getName (), new TimeoutHandler ());


                    }
                }).option (ChannelOption.SO_BACKLOG, 128).childOption (ChannelOption.SO_KEEPALIVE, true); // 

        // Bind and start to accept incoming connections.
        b.bind (PORT).sync ();

而文件发送处理程序插入在 ProtocolMessageInboundHandler 之后(仅修改 byte[] 对象并传递 bytebuf 对象)。所以文件发送处理程序和？netty？之间没有其他处理程序？

Answer 1

如果您想发送FileRegion，您的管道中应该有一个可以发送此类对象的处理程序。 Netty 中最常用的用于此目的的类是 ChunkedWriteHandler 。这也用在 example 中对于DefaultFileRegion。

将以下代码添加到初始化程序中以使其支持 FileRegion:

ch.pipeline ().addLast(new ChunkedWriteHandler());