org.jboss.netty.handler.codec.http
Class HttpContentDecoder

java.lang.Object
  org.jboss.netty.channel.SimpleChannelUpstreamHandler
      org.jboss.netty.handler.codec.http.HttpContentDecoder

All Implemented Interfaces:

ChannelHandler, ChannelUpstreamHandler

Direct Known Subclasses:

HttpContentDecompressor

public abstract class HttpContentDecoder
extends SimpleChannelUpstreamHandler

Decodes the content of the received HttpRequest and HttpChunk. The original content is replaced with the new content decoded by the DecoderEmbedder, which is created by newContentDecoder(String). Once decoding is finished, the value of the 'Content-Encoding' header is set to the target content encoding, as returned by getTargetContentEncoding(String). Also, the 'Content-Length' header is updated to the length of the decoded content. If the content encoding of the original is not supported by the decoder, newContentDecoder(String) should return null so that no decoding occurs (i.e. pass-through).

Please note that this is an abstract class. You have to extend this class and implement newContentDecoder(String) properly to make this class functional. For example, refer to the source code of HttpContentDecompressor.

This handler must be placed after HttpMessageDecoder in the pipeline so that this handler can intercept HTTP requests after HttpMessageDecoder converts ChannelBuffers into HTTP requests.

Version:

$Rev: 2368 $, $Date: 2010-10-18 17:19:03 +0900 (Mon, 18 Oct 2010) $

Author:

The Netty Project, Trustin Lee

Nested Class Summary

Nested classes/interfaces inherited from interface org.jboss.netty.channel.ChannelHandler

ChannelHandler.Sharable

Constructor Summary

protected

HttpContentDecoder() Creates a new instance.

Method Summary

protected String	getTargetContentEncoding(String contentEncoding) Returns the expected content encoding of the decoded content.
void	messageReceived(ChannelHandlerContext ctx, MessageEvent e) Invoked when a message object (e.g: ChannelBuffer) was received from a remote peer.
protected abstract DecoderEmbedder<ChannelBuffer>	newContentDecoder(String contentEncoding) Returns a new DecoderEmbedder that decodes the HTTP message content encoded in the specified contentEncoding.

Methods inherited from class org.jboss.netty.channel.SimpleChannelUpstreamHandler

channelBound, channelClosed, channelConnected, channelDisconnected, channelInterestChanged, channelOpen, channelUnbound, childChannelClosed, childChannelOpen, exceptionCaught, handleUpstream, writeComplete

Methods inherited from class java.lang.Object

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

Constructor Detail

HttpContentDecoder

protected HttpContentDecoder()

Creates a new instance.

Method Detail

messageReceived

public void messageReceived(ChannelHandlerContext ctx,
                            MessageEvent e)
                     throws Exception

Description copied from class: SimpleChannelUpstreamHandler

Invoked when a message object (e.g: ChannelBuffer) was received from a remote peer.

Overrides:

messageReceived in class SimpleChannelUpstreamHandler

Throws:

Exception

newContentDecoder

protected abstract DecoderEmbedder<ChannelBuffer> newContentDecoder(String contentEncoding)
                                                             throws Exception

Returns a new DecoderEmbedder that decodes the HTTP message content encoded in the specified contentEncoding.

Parameters:

contentEncoding - the value of the "Content-Encoding" header

Returns:

a new DecoderEmbedder if the specified encoding is supported. null otherwise (alternatively, you can throw an exception to block unknown encoding).

Throws:

Exception

getTargetContentEncoding

protected String getTargetContentEncoding(String contentEncoding)
                                   throws Exception

Returns the expected content encoding of the decoded content. This method returns "identity" by default, which is the case for most decoders.

Parameters:

contentEncoding - the value of the "Content-Encoding" header

Returns:

the expected content encoding of the new content

Throws:

Exception