io.netty.handler.codec.http

Class HttpResponseDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder

io.netty.handler.codec.http.HttpObjectDecoder

io.netty.handler.codec.http.HttpResponseDecoder

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

public class HttpResponseDecoder
extends HttpObjectDecoder

Decodes ByteBufs into HttpResponses and HttpContents.

Parameters that prevents excessive memory consumption

Name	Meaning
maxInitialLineLength	The maximum length of the initial line (e.g. "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 exceeds this value, the transfer encoding of the decoded response will be converted to 'chunked' and the content will be split into multiple HttpContents. If the transfer encoding of the HTTP response is 'chunked' already, each chunk will be split into smaller chunks if the length of the chunk exceeds this value. If you prefer not to handle HttpContents in your handler, insert HttpObjectAggregator after this decoder in the ChannelPipeline.

Decoding a response for a HEAD request

Unlike other HTTP requests, the successful response of a HEAD request does not have any content even if there is Content-Length header. Because HttpResponseDecoder is not able to determine if the response currently being decoded is associated with a HEAD request, you must override HttpObjectDecoder.isContentAlwaysEmpty(HttpMessage) to return true for the response of the HEAD request.

If you are writing an HTTP client that issues a HEAD request, please use HttpClientCodec instead of this decoder. It will perform additional state management to handle the responses for HEAD requests correctly.

Decoding a response for a CONNECT request

You also need to do additional state management to handle the response of a CONNECT request properly, like you did for HEAD. One difference is that the decoder should stop decoding completely after decoding the successful 200 response since the connection is not an HTTP connection anymore.

HttpClientCodec also handles this edge case correctly, so you have to use HttpClientCodec if you are writing an HTTP client that issues a CONNECT request.

Nested Class Summary

Nested classes/interfaces inherited from class io.netty.handler.codec.ByteToMessageDecoder

ByteToMessageDecoder.Cumulator

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

ChannelHandler.Sharable

Field Summary

Fields inherited from class io.netty.handler.codec.http.HttpObjectDecoder

validateHeaders

Fields inherited from class io.netty.handler.codec.ByteToMessageDecoder

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors

Constructor and Description
HttpResponseDecoder() Creates a new instance with the default maxInitialLineLength (4096), maxHeaderSize (8192), and maxChunkSize (8192).
HttpResponseDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize) Creates a new instance with the specified parameters.
HttpResponseDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders)
HttpResponseDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders, int initialBufferSize)

Method Summary

Modifier and Type	Method and Description
protected HttpMessage	createInvalidMessage()
protected HttpMessage	createMessage(String[] initialLine)
protected boolean	isDecodingRequest()

Methods inherited from class io.netty.handler.codec.http.HttpObjectDecoder

decode, decodeLast, isContentAlwaysEmpty, reset, userEventTriggered

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

actualReadableBytes, callDecode, channelInactive, channelRead, channelReadComplete, discardSomeReadBytes, handlerRemoved, handlerRemoved0, internalBuffer, isSingleDecode, setCumulator, setDiscardAfterReads, setSingleDecode

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, handlerAdded, isSharable

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty.channel.ChannelHandler

handlerAdded

Constructor Detail

HttpResponseDecoder

public HttpResponseDecoder()

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

HttpResponseDecoder

public HttpResponseDecoder(int maxInitialLineLength,
                           int maxHeaderSize,
                           int maxChunkSize)

Creates a new instance with the specified parameters.

HttpResponseDecoder

public HttpResponseDecoder(int maxInitialLineLength,
                           int maxHeaderSize,
                           int maxChunkSize,
                           boolean validateHeaders)

HttpResponseDecoder

public HttpResponseDecoder(int maxInitialLineLength,
                           int maxHeaderSize,
                           int maxChunkSize,
                           boolean validateHeaders,
                           int initialBufferSize)

Method Detail

createMessage

protected HttpMessage createMessage(String[] initialLine)

Specified by:

createMessage in class HttpObjectDecoder

createInvalidMessage

protected HttpMessage createInvalidMessage()

Specified by:

createInvalidMessage in class HttpObjectDecoder

isDecodingRequest

protected boolean isDecodingRequest()

Specified by:

isDecodingRequest in class HttpObjectDecoder