Class HttpContentDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.MessageToMessageDecoder<HttpObject>

io.netty.handler.codec.http.HttpContentDecoder

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

Direct Known Subclasses:

HttpContentDecompressor

public abstract class HttpContentDecoder
extends MessageToMessageDecoder<HttpObject>

Decodes the content of the received HttpRequest and HttpContent. The original content is replaced with the new content decoded by the EmbeddedChannel, 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 HttpObjectDecoder in the pipeline so that this handler can intercept HTTP requests after HttpObjectDecoder converts ByteBufs into HTTP requests.

Nested Class Summary

Nested classes/interfaces inherited from interface ChannelHandler

ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field	Description
protected ChannelHandlerContext	ctx

Constructor Summary

Constructors

Constructor	Description
HttpContentDecoder()

Method Summary

Modifier and Type	Method	Description
void	channelInactive(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelInactive() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelReadComplete(ChannelHandlerContext ctx)	Calls ChannelHandlerContext.fireChannelReadComplete() to forward to the next ChannelInboundHandler in the ChannelPipeline.
protected void	decode(ChannelHandlerContext ctx, HttpObject msg, List<Object> out)	Decode from one message to an other.
protected String	getTargetContentEncoding(String contentEncoding)	Returns the expected content encoding of the decoded content.
void	handlerAdded(ChannelHandlerContext ctx)	Do nothing by default, sub-classes may override this method.
void	handlerRemoved(ChannelHandlerContext ctx)	Do nothing by default, sub-classes may override this method.
protected abstract EmbeddedChannel	newContentDecoder(String contentEncoding)	Returns a new EmbeddedChannel that decodes the HTTP message content encoded in the specified contentEncoding.

Methods inherited from class MessageToMessageDecoder

acceptInboundMessage, channelRead

Methods inherited from class ChannelInboundHandlerAdapter

channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

Methods inherited from class ChannelHandlerAdapter

ensureNotSharable, isSharable

Methods inherited from class Object

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

Field Details

ctx

protected ChannelHandlerContext ctx

Constructor Details

HttpContentDecoder

public HttpContentDecoder()

Method Details

decode

protected void decode(ChannelHandlerContext ctx,
 HttpObject msg,
 List<Object> out)
               throws Exception

Description copied from class: MessageToMessageDecoder

Decode from one message to an other. This method will be called for each written message that can be handled by this decoder.

Specified by:

decode in class MessageToMessageDecoder<HttpObject>

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageDecoder belongs to

msg - the message to decode to an other one

out - the List to which decoded messages should be added

Throws:

Exception - is thrown if an error occurs

channelReadComplete

public void channelReadComplete(ChannelHandlerContext ctx)
                         throws Exception

Description copied from class: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireChannelReadComplete() to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

channelReadComplete in interface ChannelInboundHandler

Overrides:

channelReadComplete in class MessageToMessageDecoder<HttpObject>

Throws:

Exception

newContentDecoder

protected abstract EmbeddedChannel newContentDecoder(String contentEncoding)
                                              throws Exception

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

Parameters:

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

Returns:

a new EmbeddedChannel 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 getMethod 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

handlerRemoved

public void handlerRemoved(ChannelHandlerContext ctx)
                    throws Exception

Description copied from class: ChannelHandlerAdapter

Do nothing by default, sub-classes may override this method.

Specified by:

handlerRemoved in interface ChannelHandler

Overrides:

handlerRemoved in class ChannelHandlerAdapter

Throws:

Exception

channelInactive

public void channelInactive(ChannelHandlerContext ctx)
                     throws Exception

Description copied from class: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireChannelInactive() to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

channelInactive in interface ChannelInboundHandler

Overrides:

channelInactive in class ChannelInboundHandlerAdapter

Throws:

Exception

handlerAdded

public void handlerAdded(ChannelHandlerContext ctx)
                  throws Exception

Description copied from class: ChannelHandlerAdapter

Do nothing by default, sub-classes may override this method.

Specified by:

handlerAdded in interface ChannelHandler

Overrides:

handlerAdded in class ChannelHandlerAdapter

Throws:

Exception