Class HttpResponseDecoder
- All Implemented Interfaces:
ChannelHandler
,ChannelInboundHandler
- Direct Known Subclasses:
HttpClientCodec.Decoder
ByteBuf
s into HttpResponse
s and
HttpContent
s.
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
TooLongHttpLineException will be raised. |
maxHeaderSize |
The maximum length of all headers. If the sum of the length of each
header exceeds this value, a TooLongHttpHeaderException 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
HttpContent s. 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
HttpContent s in your handler, insert HttpObjectAggregator
after this decoder in the ChannelPipeline . |
Parameters that control parsing behavior
Name | Default value | Meaning |
---|---|---|
allowDuplicateContentLengths |
false | When set to false , will reject any messages that contain multiple Content-Length header fields.
When set to true , will allow multiple Content-Length headers only if they are all the same decimal value.
The duplicated field-values will be replaced with a single valid Content-Length field.
See RFC 7230, Section 3.3.2. |
allowPartialChunks |
true | If the length of a chunk exceeds the ByteBuf s readable bytes and allowPartialChunks
is set to true , the chunk will be split into multiple HttpContent s.
Otherwise, if the chunk size does not exceed maxChunkSize and allowPartialChunks
is set to false , the ByteBuf is not decoded into an HttpContent until
the readable bytes are greater or equal to the chunk size. |
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.
Header Validation
It is recommended to always enable header validation.Without header validation, your system can become vulnerable to CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') .
This recommendation stands even when both peers in the HTTP exchange are trusted, as it helps with defence-in-depth.
-
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
FieldsFields inherited from class io.netty.handler.codec.http.HttpObjectDecoder
DEFAULT_ALLOW_DUPLICATE_CONTENT_LENGTHS, DEFAULT_ALLOW_PARTIAL_CHUNKS, DEFAULT_CHUNKED_SUPPORTED, DEFAULT_INITIAL_BUFFER_SIZE, DEFAULT_MAX_CHUNK_SIZE, DEFAULT_MAX_HEADER_SIZE, DEFAULT_MAX_INITIAL_LINE_LENGTH, DEFAULT_VALIDATE_HEADERS, headersFactory, trailersFactory, validateHeaders
Fields inherited from class io.netty.handler.codec.ByteToMessageDecoder
COMPOSITE_CUMULATOR, MERGE_CUMULATOR
-
Constructor Summary
ConstructorsConstructorDescriptionCreates a new instance with the defaultmaxInitialLineLength (4096)
,maxHeaderSize (8192)
, andmaxChunkSize (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) Deprecated.HttpResponseDecoder
(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders, int initialBufferSize) Deprecated.Prefer theHttpResponseDecoder(HttpDecoderConfig)
constructor.HttpResponseDecoder
(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders, int initialBufferSize, boolean allowDuplicateContentLengths) Deprecated.Prefer theHttpResponseDecoder(HttpDecoderConfig)
constructor.HttpResponseDecoder
(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders, int initialBufferSize, boolean allowDuplicateContentLengths, boolean allowPartialChunks) Deprecated.Prefer theHttpResponseDecoder(HttpDecoderConfig)
constructor.HttpResponseDecoder
(HttpDecoderConfig config) Creates a new instance with the specified configuration. -
Method Summary
Modifier and TypeMethodDescriptionprotected HttpMessage
protected HttpMessage
createMessage
(String[] initialLine) protected boolean
Methods inherited from class io.netty.handler.codec.http.HttpObjectDecoder
decode, decodeLast, handlerRemoved0, handleTransferEncodingChunkedWithContentLength, isContentAlwaysEmpty, isSwitchingToNonHttp1Protocol, isValidating, reset, splitFirstWordInitialLine, splitHeaderName, splitSecondWordInitialLine, splitThirdWordInitialLine, userEventTriggered
Methods inherited from class io.netty.handler.codec.ByteToMessageDecoder
actualReadableBytes, callDecode, channelInactive, channelRead, channelReadComplete, discardSomeReadBytes, handlerRemoved, 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
-
Field Details
-
UNKNOWN_STATUS
-
-
Constructor Details
-
HttpResponseDecoder
public HttpResponseDecoder()Creates a new instance with the defaultmaxInitialLineLength (4096)
,maxHeaderSize (8192)
, andmaxChunkSize (8192)
. -
HttpResponseDecoder
public HttpResponseDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize) Creates a new instance with the specified parameters. -
HttpResponseDecoder
@Deprecated public HttpResponseDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders) Deprecated.Prefer theHttpResponseDecoder(HttpDecoderConfig)
constructor. -
HttpResponseDecoder
@Deprecated public HttpResponseDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders, int initialBufferSize) Deprecated.Prefer theHttpResponseDecoder(HttpDecoderConfig)
constructor. -
HttpResponseDecoder
@Deprecated public HttpResponseDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders, int initialBufferSize, boolean allowDuplicateContentLengths) Deprecated.Prefer theHttpResponseDecoder(HttpDecoderConfig)
constructor. -
HttpResponseDecoder
@Deprecated public HttpResponseDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean validateHeaders, int initialBufferSize, boolean allowDuplicateContentLengths, boolean allowPartialChunks) Deprecated.Prefer theHttpResponseDecoder(HttpDecoderConfig)
constructor. -
HttpResponseDecoder
Creates a new instance with the specified configuration.
-
-
Method Details
-
createMessage
- Specified by:
createMessage
in classHttpObjectDecoder
-
createInvalidMessage
- Specified by:
createInvalidMessage
in classHttpObjectDecoder
-
isDecodingRequest
protected boolean isDecodingRequest()- Specified by:
isDecodingRequest
in classHttpObjectDecoder
-
HttpResponseDecoder(HttpDecoderConfig)
constructor.