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

java.lang.Object
  org.jboss.netty.channel.SimpleChannelHandler
      org.jboss.netty.handler.codec.http.HttpContentEncoder

All Implemented Interfaces:

ChannelDownstreamHandler, ChannelHandler, ChannelUpstreamHandler

Direct Known Subclasses:

HttpContentCompressor

public abstract class HttpContentEncoder
extends SimpleChannelHandler

Encodes the content of the outbound HttpResponse and HttpChunk. The original content is replaced with the new content encoded by the EncoderEmbedder, which is created by newContentEncoder(String). Once encoding 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 encoded content. If there is no supported encoding in the corresponding HttpRequest's "Accept-Encoding" header, newContentEncoder(String) should return null so that no encoding occurs (i.e. pass-through).

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

This handler must be placed after HttpMessageEncoder in the pipeline so that this handler can intercept HTTP responses before HttpMessageEncoder converts them into ChannelBuffers.

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

HttpContentEncoder() Creates a new instance.

Method Summary

protected abstract String	getTargetContentEncoding(String acceptEncoding) Returns the expected content encoding of the encoded content.
void	messageReceived(ChannelHandlerContext ctx, MessageEvent e) Invoked when a message object (e.g: ChannelBuffer) was received from a remote peer.
protected abstract EncoderEmbedder<ChannelBuffer>	newContentEncoder(String acceptEncoding) Returns a new EncoderEmbedder that encodes the HTTP message content.
void	writeRequested(ChannelHandlerContext ctx, MessageEvent e) Invoked when Channel.write(Object) is called.

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

bindRequested, channelBound, channelClosed, channelConnected, channelDisconnected, channelInterestChanged, channelOpen, channelUnbound, childChannelClosed, childChannelOpen, closeRequested, connectRequested, disconnectRequested, exceptionCaught, handleDownstream, handleUpstream, setInterestOpsRequested, unbindRequested, writeComplete

Methods inherited from class java.lang.Object

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

Constructor Detail

HttpContentEncoder

protected HttpContentEncoder()

Creates a new instance.

Method Detail

messageReceived

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

Description copied from class: SimpleChannelHandler

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

Overrides:

messageReceived in class SimpleChannelHandler

Throws:

Exception

writeRequested

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

Description copied from class: SimpleChannelHandler

Invoked when Channel.write(Object) is called.

Overrides:

writeRequested in class SimpleChannelHandler

Throws:

Exception

newContentEncoder

protected abstract EncoderEmbedder<ChannelBuffer> newContentEncoder(String acceptEncoding)
                                                             throws Exception

Returns a new EncoderEmbedder that encodes the HTTP message content.

Parameters:

acceptEncoding - the value of the "Accept-Encoding" header

Returns:

a new EncoderEmbedder if there is a supported encoding in acceptEncoding. null otherwise.

Throws:

Exception

getTargetContentEncoding

protected abstract String getTargetContentEncoding(String acceptEncoding)
                                            throws Exception

Returns the expected content encoding of the encoded content.

Parameters:

acceptEncoding - the value of the "Accept-Encoding" header

Returns:

the expected content encoding of the new content

Throws:

Exception