Class ProtobufVarint32FrameDecoder

  extended by
      extended by org.jboss.netty.handler.codec.frame.FrameDecoder
          extended by org.jboss.netty.handler.codec.protobuf.ProtobufVarint32FrameDecoder
All Implemented Interfaces:
ChannelHandler, ChannelUpstreamHandler

public class ProtobufVarint32FrameDecoder
extends FrameDecoder

A decoder that splits the received ChannelBuffers dynamically by the value of the Google Protocol Buffers Base 128 Varints integer length field in the message. For example:

 BEFORE DECODE (302 bytes)       AFTER DECODE (300 bytes)
 +--------+---------------+      +---------------+
 | Length | Protobuf Data |----->| Protobuf Data |
 | 0xAC02 |  (300 bytes)  |      |  (300 bytes)  |
 +--------+---------------+      +---------------+

$Rev: 2323 $, $Date: 2010-06-24 11:13:12 +0900 (Thu, 24 Jun 2010) $
The Netty Project, Tomasz Blachowicz (, Trustin Lee
See Also:

Nested Class Summary
Nested classes/interfaces inherited from interface
Constructor Summary
          Creates a new instance.
Method Summary
protected  Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer)
          Decodes the received packets so far into a frame.
Methods inherited from class org.jboss.netty.handler.codec.frame.FrameDecoder
channelClosed, channelDisconnected, decodeLast, exceptionCaught, messageReceived
Methods inherited from class
channelBound, channelConnected, channelInterestChanged, channelOpen, channelUnbound, childChannelClosed, childChannelOpen, handleUpstream, writeComplete
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


public ProtobufVarint32FrameDecoder()
Creates a new instance.

Method Detail


protected Object decode(ChannelHandlerContext ctx,
                        Channel channel,
                        ChannelBuffer buffer)
                 throws Exception
Description copied from class: FrameDecoder
Decodes the received packets so far into a frame.

Specified by:
decode in class FrameDecoder
ctx - the context of this handler
channel - the current channel
buffer - the cumulative buffer of received packets so far. Note that the buffer might be empty, which means you should not make an assumption that the buffer contains at least one byte in your decoder implementation.
the decoded frame if a full frame was received and decoded. null if there's not enough data in the buffer to decode a frame.

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