org.jboss.netty.handler.codec.http

类 HttpMessageDecoder

java.lang.Object

org.jboss.netty.channel.SimpleChannelUpstreamHandler

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

org.jboss.netty.handler.codec.replay.ReplayingDecoder<HttpMessageDecoder.State>

org.jboss.netty.handler.codec.http.HttpMessageDecoder

所有已实现的接口:

ChannelHandler, ChannelUpstreamHandler, LifeCycleAwareChannelHandler

直接已知子类:

HttpRequestDecoder, HttpResponseDecoder, RtspMessageDecoder

public abstract class HttpMessageDecoder
extends ReplayingDecoder<HttpMessageDecoder.State>

Decodes ChannelBuffers into HttpMessages and HttpChunks.

Parameters that prevents excessive memory consumption

Name	Meaning
maxInitialLineLength	The maximum length of the initial line (e.g. "GET / HTTP/1.0" or "HTTP/1.0 200 OK") If the length of the initial line exceeds this value, a TooLongFrameException will be raised.
maxHeaderSize	The maximum length of all headers. If the sum of the length of each header exceeds this value, a TooLongFrameException will be raised.
maxChunkSize	The maximum length of the content or each chunk. If the content length (or the length of each chunk) exceeds this value, the content or chunk will be split into multiple HttpChunks whose length is maxChunkSize at maximum.

Chunked Content

If the content of an HTTP message is greater than maxChunkSize or the transfer encoding of the HTTP message is 'chunked', this decoder generates one HttpMessage instance and its following HttpChunks per single HTTP message to avoid excessive memory consumption. For example, the following HTTP message:

 GET / HTTP/1.1
 Transfer-Encoding: chunked

 1a
 abcdefghijklmnopqrstuvwxyz
 10
 1234567890abcdef
 0
 Content-MD5: ...
 [blank line]
 

triggers HttpRequestDecoder to generate 4 objects:

1. An HttpRequest whose chunked property is true,
2. The first HttpChunk whose content is 'abcdefghijklmnopqrstuvwxyz',
3. The second HttpChunk whose content is '1234567890abcdef', and
4. An HttpChunkTrailer which marks the end of the content.

If you prefer not to handle HttpChunks by yourself for your convenience, insert HttpChunkAggregator after this decoder in the ChannelPipeline. However, please note that your server might not be as memory efficient as without the aggregator.

Extensibility

Please note that this decoder is designed to be extended to implement a protocol derived from HTTP, such as RTSP and ICAP. To implement the decoder of such a derived protocol, extend this class and implement all abstract methods properly.

嵌套类概要

嵌套类

限定符和类型	类和说明
protected static class	HttpMessageDecoder.State The internal state of HttpMessageDecoder.

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

限定符	构造器和说明
protected	HttpMessageDecoder() Creates a new instance with the default maxInitialLineLength (4096}, maxHeaderSize (8192), and maxChunkSize (8192).
protected	HttpMessageDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize) Creates a new instance with the specified parameters.

方法概要

方法

限定符和类型	方法和说明
protected abstract HttpMessage	createMessage(java.lang.String[] initialLine)
protected java.lang.Object	decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer, HttpMessageDecoder.State state) Decodes the received packets so far into a frame.
protected boolean	isContentAlwaysEmpty(HttpMessage msg)
protected abstract boolean	isDecodingRequest()

从类继承的方法 org.jboss.netty.handler.codec.replay.ReplayingDecoder

checkpoint, checkpoint, cleanup, decode, decodeLast, decodeLast, getState, internalBuffer, messageReceived, setState

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

actualReadableBytes, afterAdd, afterRemove, appendToCumulation, beforeAdd, beforeRemove, channelClosed, channelDisconnected, exceptionCaught, extractFrame, getMaxCumulationBufferCapacity, getMaxCumulationBufferComponents, isUnfold, newCumulationBuffer, 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

HttpMessageDecoder

protected HttpMessageDecoder()

Creates a new instance with the default maxInitialLineLength (4096}, maxHeaderSize (8192), and maxChunkSize (8192).

HttpMessageDecoder

protected HttpMessageDecoder(int maxInitialLineLength,
                  int maxHeaderSize,
                  int maxChunkSize)

Creates a new instance with the specified parameters.

方法详细资料

decode

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

从类复制的说明: ReplayingDecoder

Decodes the received packets so far into a frame.

指定者:

decode 在类中 ReplayingDecoder<HttpMessageDecoder.State>

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.

state - the current decoder state (null if unused)

返回:

the decoded frame

抛出:

java.lang.Exception

isContentAlwaysEmpty

protected boolean isContentAlwaysEmpty(HttpMessage msg)

isDecodingRequest

protected abstract boolean isDecodingRequest()

createMessage

protected abstract HttpMessage createMessage(java.lang.String[] initialLine)
                                      throws java.lang.Exception

抛出:

java.lang.Exception