org.jboss.netty.handler.codec.frame

类 FixedLengthFrameDecoder

java.lang.Object

org.jboss.netty.channel.SimpleChannelUpstreamHandler

org.jboss.netty.handler.codec.frame.FrameDecoder

org.jboss.netty.handler.codec.frame.FixedLengthFrameDecoder

所有已实现的接口:

ChannelHandler, ChannelUpstreamHandler, LifeCycleAwareChannelHandler

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 |
 +-----+-----+-----+
 

嵌套类概要

从接口继承的嵌套类/接口 org.jboss.netty.channel.ChannelHandler

ChannelHandler.Sharable

字段概要

从类继承的字段 org.jboss.netty.handler.codec.frame.FrameDecoder

cumulation, DEFAULT_MAX_COMPOSITEBUFFER_COMPONENTS

构造器概要

构造器

构造器和说明
FixedLengthFrameDecoder(int frameLength) Calls FixedLengthFrameDecoder(int, boolean) with false
FixedLengthFrameDecoder(int frameLength, boolean allocateFullBuffer) Creates a new instance.

方法概要

方法

限定符和类型	方法和说明
protected java.lang.Object	decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) Decodes the received packets so far into a frame.
protected ChannelBuffer	newCumulationBuffer(ChannelHandlerContext ctx, int minimumCapacity) Create a new ChannelBuffer which is used for the cumulation.

从类继承的方法 org.jboss.netty.handler.codec.frame.FrameDecoder

actualReadableBytes, afterAdd, afterRemove, appendToCumulation, beforeAdd, beforeRemove, channelClosed, channelDisconnected, cleanup, decodeLast, exceptionCaught, extractFrame, getMaxCumulationBufferCapacity, getMaxCumulationBufferComponents, internalBuffer, isUnfold, messageReceived, replace, setMaxCumulationBufferCapacity, setMaxCumulationBufferComponents, setUnfold, unfoldAndFireMessageReceived, updateCumulation

从类继承的方法 org.jboss.netty.channel.SimpleChannelUpstreamHandler

channelBound, channelConnected, channelInterestChanged, channelOpen, channelUnbound, childChannelClosed, childChannelOpen, handleUpstream, writeComplete

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

FixedLengthFrameDecoder

public FixedLengthFrameDecoder(int frameLength)

Calls FixedLengthFrameDecoder(int, boolean) with false

FixedLengthFrameDecoder

public FixedLengthFrameDecoder(int frameLength,
                       boolean allocateFullBuffer)

Creates a new instance.

参数:

frameLength - the length of the frame

allocateFullBuffer - true if the cumulative ChannelBuffer should use the frameLength as its initial size

方法详细资料

decode

protected java.lang.Object decode(ChannelHandlerContext ctx,
                      Channel channel,
                      ChannelBuffer buffer)
                           throws java.lang.Exception

从类复制的说明: FrameDecoder

Decodes the received packets so far into a frame. If an sub-class wants to extract a frame out of the buffer it should use the FrameDecoder.extractFrame(ChannelBuffer, int, int) method, to make optimizations easier later.

指定者:

decode 在类中 FrameDecoder

参数:

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.

返回:

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.

抛出:

java.lang.Exception

newCumulationBuffer

protected ChannelBuffer newCumulationBuffer(ChannelHandlerContext ctx,
                                int minimumCapacity)

从类复制的说明: FrameDecoder

Create a new ChannelBuffer which is used for the cumulation. Sub-classes may override this.

覆盖:

newCumulationBuffer 在类中 FrameDecoder

参数:

ctx - ChannelHandlerContext for this handler

返回:

buffer the ChannelBuffer which is used for cumulation