Class ChunkedWriteHandler

java.lang.Object
io.netty.channel.ChannelHandlerAdapter
io.netty.channel.ChannelInboundHandlerAdapter
io.netty.channel.ChannelDuplexHandler
io.netty.handler.stream.ChunkedWriteHandler
All Implemented Interfaces:
ChannelHandler, ChannelInboundHandler, ChannelOutboundHandler
public class ChunkedWriteHandler extends ChannelDuplexHandler
A ChannelHandler that adds support for writing a large data stream asynchronously neither spending a lot of memory nor getting OutOfMemoryError. Large data streaming such as file transfer requires complicated state management in a ChannelHandler implementation. ChunkedWriteHandler manages such complicated states so that you can send a large data stream without difficulties.

To use ChunkedWriteHandler in your application, you have to insert a new ChunkedWriteHandler instance: 

ChannelPipeline p = ...;
p.addLast("streamer", new ChunkedWriteHandler());
p.addLast("handler", new MyHandler());
Once inserted, you can write a ChunkedInput so that the ChunkedWriteHandler can pick it up and fetch the content of the stream chunk by chunk and write the fetched chunk downstream: 
Channel ch = ...;
ch.write(new ChunkedFile(new File("video.mkv"));

Sending a stream which generates a chunk intermittently

Some ChunkedInput generates a chunk on a certain event or timing. Such ChunkedInput implementation often returns null on ChunkedInput.readChunk(ChannelHandlerContext), resulting in the indefinitely suspended transfer. To resume the transfer when a new chunk is available, you have to call resumeTransfer().