io.netty.handler.codec.http

Class HttpObjectAggregator

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

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

io.netty.handler.codec.MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

io.netty.handler.codec.http.HttpObjectAggregator

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

Direct Known Subclasses:

HttpClientUpgradeHandler, HttpServerUpgradeHandler

public class HttpObjectAggregator
extends MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

A ChannelHandler that aggregates an HttpMessage and its following HttpContents into a single FullHttpRequest or FullHttpResponse (depending on if it used to handle requests or responses) with no following HttpContents. It is useful when you don't want to take care of HTTP messages whose transfer encoding is 'chunked'. Insert this handler after HttpResponseDecoder in the ChannelPipeline if being used to handle responses, or after HttpRequestDecoder and HttpResponseEncoder in the ChannelPipeline if being used to handle requests.

  ChannelPipeline p = ...;
  ...
  p.addLast("decoder", new HttpRequestDecoder());
  p.addLast("encoder", new HttpResponseEncoder());
  p.addLast("aggregator", new HttpObjectAggregator(1048576));
  ...
  p.addLast("handler", new HttpRequestHandler());
  

For convenience, consider putting a HttpServerCodec before the HttpObjectAggregator as it functions as both a HttpRequestDecoder and a HttpResponseEncoder.

Be aware that HttpObjectAggregator may end up sending a HttpResponse:

Response Status	Condition When Sent
100 Continue	A '100-continue' expectation is received and the 'content-length' doesn't exceed maxContentLength
417 Expectation Failed	A '100-continue' expectation is received and the 'content-length' exceeds maxContentLength
413 Request Entity Too Large	Either the 'content-length' or the bytes received so far exceed maxContentLength

See Also:

FullHttpRequest, FullHttpResponse, HttpResponseDecoder, HttpServerCodec

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor and Description
HttpObjectAggregator(int maxContentLength) Creates a new instance.
HttpObjectAggregator(int maxContentLength, boolean closeOnExpectationFailed) Creates a new instance.

Method Summary

Modifier and Type	Method and Description
protected void	aggregate(FullHttpMessage aggregated, HttpContent content) Transfers the information provided by the specified content message to the specified aggregated message.
protected FullHttpMessage	beginAggregation(HttpMessage start, ByteBuf content) Creates a new aggregated message from the specified start message and the specified content.
protected boolean	closeAfterContinueResponse(Object msg) Determine if the channel should be closed after the result of MessageAggregator.newContinueResponse(Object, int, ChannelPipeline) is written.
protected void	finishAggregation(FullHttpMessage aggregated) Invoked when the specified aggregated message is about to be passed to the next handler in the pipeline.
protected void	handleOversizedMessage(ChannelHandlerContext ctx, HttpMessage oversized) Invoked when an incoming request exceeds the maximum content length.
protected boolean	ignoreContentAfterContinueResponse(Object msg) Determine if all objects for the current request/response should be ignored or not.
protected boolean	isAggregated(HttpObject msg) Returns true if and only if the specified message is already aggregated.
protected boolean	isContentLengthInvalid(HttpMessage start, int maxContentLength) Determine if the message start's content length is known, and if it greater than maxContentLength.
protected boolean	isContentMessage(HttpObject msg) Returns true if and only if the specified message is a content message.
protected boolean	isLastContentMessage(HttpContent msg) Returns true if and only if the specified message is the last content message.
protected boolean	isStartMessage(HttpObject msg) Returns true if and only if the specified message is a start message.
protected Object	newContinueResponse(HttpMessage start, int maxContentLength, ChannelPipeline pipeline) Returns the 'continue response' for the specified start message if necessary.

Methods inherited from class io.netty.handler.codec.MessageAggregator

acceptInboundMessage, channelInactive, channelReadComplete, ctx, decode, handlerAdded, handlerRemoved, isHandlingOversizedMessage, maxContentLength, maxCumulationBufferComponents, setMaxCumulationBufferComponents

Methods inherited from class io.netty.handler.codec.MessageToMessageDecoder

channelRead

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, isSharable

Methods inherited from class java.lang.Object

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

Constructor Detail

HttpObjectAggregator

public HttpObjectAggregator(int maxContentLength)

Creates a new instance.

Parameters:

maxContentLength - the maximum length of the aggregated content in bytes. If the length of the aggregated content exceeds this value, handleOversizedMessage(ChannelHandlerContext, HttpMessage) will be called.

HttpObjectAggregator

public HttpObjectAggregator(int maxContentLength,
                            boolean closeOnExpectationFailed)

Creates a new instance.

Parameters:

maxContentLength - the maximum length of the aggregated content in bytes. If the length of the aggregated content exceeds this value, handleOversizedMessage(ChannelHandlerContext, HttpMessage) will be called.

closeOnExpectationFailed - If a 100-continue response is detected but the content length is too large then true means close the connection. otherwise the connection will remain open and data will be consumed and discarded until the next request is received.

Method Detail

isStartMessage

protected boolean isStartMessage(HttpObject msg)
                          throws Exception

Description copied from class: MessageAggregator

Returns true if and only if the specified message is a start message. Typically, this method is implemented as a single return statement with instanceof:

 return msg instanceof MyStartMessage;
 

Specified by:

isStartMessage in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Throws:

Exception

isContentMessage

protected boolean isContentMessage(HttpObject msg)
                            throws Exception

Description copied from class: MessageAggregator

Returns true if and only if the specified message is a content message. Typically, this method is implemented as a single return statement with instanceof:

 return msg instanceof MyContentMessage;
 

Specified by:

isContentMessage in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Throws:

Exception

isLastContentMessage

protected boolean isLastContentMessage(HttpContent msg)
                                throws Exception

Description copied from class: MessageAggregator

Returns true if and only if the specified message is the last content message. Typically, this method is implemented as a single return statement with instanceof:

 return msg instanceof MyLastContentMessage;
 

or with instanceof and boolean field check:

 return msg instanceof MyContentMessage && msg.isLastFragment();
 

Specified by:

isLastContentMessage in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Throws:

Exception

isAggregated

protected boolean isAggregated(HttpObject msg)
                        throws Exception

Description copied from class: MessageAggregator

Returns true if and only if the specified message is already aggregated. If this method returns true, this handler will simply forward the message to the next handler as-is.

Specified by:

isAggregated in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Throws:

Exception

isContentLengthInvalid

protected boolean isContentLengthInvalid(HttpMessage start,
                                         int maxContentLength)

Description copied from class: MessageAggregator

Determine if the message start's content length is known, and if it greater than maxContentLength.

Specified by:

isContentLengthInvalid in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Parameters:

start - The message which may indicate the content length.

maxContentLength - The maximum allowed content length.

Returns:

true if the message start's content length is known, and if it greater than maxContentLength. false otherwise.

newContinueResponse

protected Object newContinueResponse(HttpMessage start,
                                     int maxContentLength,
                                     ChannelPipeline pipeline)

Description copied from class: MessageAggregator

Returns the 'continue response' for the specified start message if necessary. For example, this method is useful to handle an HTTP 100-continue header.

Specified by:

newContinueResponse in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Returns:

the 'continue response', or null if there's no message to send

closeAfterContinueResponse

protected boolean closeAfterContinueResponse(Object msg)

Description copied from class: MessageAggregator

Determine if the channel should be closed after the result of MessageAggregator.newContinueResponse(Object, int, ChannelPipeline) is written.

Specified by:

closeAfterContinueResponse in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Parameters:

msg - The return value from MessageAggregator.newContinueResponse(Object, int, ChannelPipeline).

Returns:

true if the channel should be closed after the result of MessageAggregator.newContinueResponse(Object, int, ChannelPipeline) is written. false otherwise.

ignoreContentAfterContinueResponse

protected boolean ignoreContentAfterContinueResponse(Object msg)

Description copied from class: MessageAggregator

Determine if all objects for the current request/response should be ignored or not. Messages will stop being ignored the next time MessageAggregator.isContentMessage(Object) returns true.

Specified by:

ignoreContentAfterContinueResponse in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Parameters:

msg - The return value from MessageAggregator.newContinueResponse(Object, int, ChannelPipeline).

Returns:

true if all objects for the current request/response should be ignored or not. false otherwise.

beginAggregation

protected FullHttpMessage beginAggregation(HttpMessage start,
                                           ByteBuf content)
                                    throws Exception

Description copied from class: MessageAggregator

Creates a new aggregated message from the specified start message and the specified content. If the start message implements ByteBufHolder, its content is appended to the specified content. This aggregator will continue to append the received content to the specified content.

Specified by:

beginAggregation in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Throws:

Exception

aggregate

protected void aggregate(FullHttpMessage aggregated,
                         HttpContent content)
                  throws Exception

Description copied from class: MessageAggregator

Transfers the information provided by the specified content message to the specified aggregated message. Note that the content of the specified content message has been appended to the content of the specified aggregated message already, so that you don't need to. Use this method to transfer the additional information that the content message provides to aggregated.

Overrides:

aggregate in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Throws:

Exception

finishAggregation

protected void finishAggregation(FullHttpMessage aggregated)
                          throws Exception

Description copied from class: MessageAggregator

Invoked when the specified aggregated message is about to be passed to the next handler in the pipeline.

Overrides:

finishAggregation in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Throws:

Exception

handleOversizedMessage

protected void handleOversizedMessage(ChannelHandlerContext ctx,
                                      HttpMessage oversized)
                               throws Exception

Description copied from class: MessageAggregator

Invoked when an incoming request exceeds the maximum content length. The default behvaior is to trigger an exceptionCaught() event with a TooLongFrameException.

Overrides:

handleOversizedMessage in class MessageAggregator<HttpObject,HttpMessage,HttpContent,FullHttpMessage>

Parameters:

ctx - the ChannelHandlerContext

oversized - the accumulated message up to this point, whose type is S or O

Throws:

Exception