Package io.netty.handler.flow

Class FlowControlHandler

  • All Implemented Interfaces:
    io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundHandler, io.netty.channel.ChannelOutboundHandler
    public class FlowControlHandler
extends io.netty.channel.ChannelDuplexHandler
    The FlowControlHandler ensures that only one message per read() is sent downstream. Classes such as ByteToMessageDecoder or MessageToByteEncoder are free to emit as many events as they like for any given input. A channel's auto reading configuration doesn't usually apply in these scenarios. This is causing problems in downstream ChannelHandlers that would like to hold subsequent events while they're processing one event. It's a common problem with the HttpObjectDecoder that will very often fire an HttpRequest that is immediately followed by a LastHttpContent event. 
    {@code
 ChannelPipeline pipeline = ...;

 pipeline.addLast(new HttpServerCodec());
 pipeline.addLast(new FlowControlHandler());

 pipeline.addLast(new MyExampleHandler());

 class MyExampleHandler extends ChannelInboundHandlerAdapter {
    See Also:
    ChannelConfig.setAutoRead(boolean)

    • Nested Class Summary

      • Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

        io.netty.channel.ChannelHandler.Sharable

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void channelInactive​(io.netty.channel.ChannelHandlerContext ctx)  
      void channelRead​(io.netty.channel.ChannelHandlerContext ctx, Object msg)  
      void channelReadComplete​(io.netty.channel.ChannelHandlerContext ctx)  
      void handlerAdded​(io.netty.channel.ChannelHandlerContext ctx)  
      void handlerRemoved​(io.netty.channel.ChannelHandlerContext ctx)  
      void read​(io.netty.channel.ChannelHandlerContext ctx)  

      • Methods inherited from class io.netty.channel.ChannelDuplexHandler

        bind, close, connect, deregister, disconnect, flush, write

      • Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

        channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

      • Methods inherited from class io.netty.channel.ChannelHandlerAdapter

        ensureNotSharable, isSharable

    • Constructor Detail

      • FlowControlHandler

        public FlowControlHandler()

      • FlowControlHandler

        public FlowControlHandler​(boolean releaseMessages)

    • Method Detail

      • handlerAdded

        public void handlerAdded​(io.netty.channel.ChannelHandlerContext ctx)
                  throws Exception
        Specified by:
        handlerAdded in interface io.netty.channel.ChannelHandler
        Overrides:
        handlerAdded in class io.netty.channel.ChannelHandlerAdapter
        Throws:
        Exception

      • handlerRemoved

        public void handlerRemoved​(io.netty.channel.ChannelHandlerContext ctx)
                    throws Exception
        Specified by:
        handlerRemoved in interface io.netty.channel.ChannelHandler
        Overrides:
        handlerRemoved in class io.netty.channel.ChannelHandlerAdapter
        Throws:
        Exception

      • channelInactive

        public void channelInactive​(io.netty.channel.ChannelHandlerContext ctx)
                     throws Exception
        Specified by:
        channelInactive in interface io.netty.channel.ChannelInboundHandler
        Overrides:
        channelInactive in class io.netty.channel.ChannelInboundHandlerAdapter
        Throws:
        Exception

      • read

        public void read​(io.netty.channel.ChannelHandlerContext ctx)
          throws Exception
        Specified by:
        read in interface io.netty.channel.ChannelOutboundHandler
        Overrides:
        read in class io.netty.channel.ChannelDuplexHandler
        Throws:
        Exception

      • channelRead

        public void channelRead​(io.netty.channel.ChannelHandlerContext ctx,
                        Object msg)
                 throws Exception
        Specified by:
        channelRead in interface io.netty.channel.ChannelInboundHandler
        Overrides:
        channelRead in class io.netty.channel.ChannelInboundHandlerAdapter
        Throws:
        Exception

      • channelReadComplete

        public void channelReadComplete​(io.netty.channel.ChannelHandlerContext ctx)
                         throws Exception
        Specified by:
        channelReadComplete in interface io.netty.channel.ChannelInboundHandler
        Overrides:
        channelReadComplete in class io.netty.channel.ChannelInboundHandlerAdapter
        Throws:
        Exception