Class FixedLengthFrameDecoder

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

public class FixedLengthFrameDecoder
extends FrameDecoder

A decoder that splits the received ChannelBuffers by the fixed number of bytes. For example, if you received the following four fragmented packets:

 | A | BC | DEFG | HI |
A FixedLengthFrameDecoder(3) will decode them into the following three packets with the fixed length:
 | ABC | DEF | GHI |

$Rev:231 $, $Date:2008-06-12 16:44:50 +0900 (목, 12 6월 2008) $
The Netty Project, Trustin Lee

Nested Class Summary
Nested classes/interfaces inherited from interface
Constructor Summary
FixedLengthFrameDecoder(int frameLength)
          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 FixedLengthFrameDecoder(int frameLength)
Creates a new instance.

frameLength - the length of the frame
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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