HttpObjectDecoder (Netty API Reference (4.1.87.Final))

java.lang.Object
- io.netty.channel.ChannelHandlerAdapter
- - io.netty.channel.ChannelInboundHandlerAdapter
  - - io.netty.handler.codec.ByteToMessageDecoder
    - - io.netty.handler.codec.http.HttpObjectDecoder

All Implemented Interfaces:: ChannelHandler, ChannelInboundHandler

Direct Known Subclasses:: HttpRequestDecoder, HttpResponseDecoder, RtspDecoder, RtspObjectDecoder

public abstract class HttpObjectDecoder
extends ByteToMessageDecoder

Decodes ByteBufs into HttpMessages and HttpContents.

Parameters that prevents excessive memory consumption

Name	Default value	Meaning
`maxInitialLineLength`	4096	The maximum length of the initial line (e.g. `"GET / HTTP/1.0"` or `"HTTP/1.0 200 OK"`) If the length of the initial line exceeds this value, a `TooLongHttpLineException` will be raised.
`maxHeaderSize`	8192	The maximum length of all headers. If the sum of the length of each header exceeds this value, a `TooLongHttpHeaderException` will be raised.
`maxChunkSize`	8192	The maximum length of the content or each chunk. If the content length (or the length of each chunk) exceeds this value, the content or chunk will be split into multiple `HttpContent`s whose length is `maxChunkSize` at maximum.

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.

Chunked Content

If the content of an HTTP message is greater than maxChunkSize or the transfer encoding of the HTTP message is 'chunked', this decoder generates one HttpMessage instance and its following HttpContents per single HTTP message to avoid excessive memory consumption. For example, the following HTTP message:

 GET / HTTP/1.1
 Transfer-Encoding: chunked

 1a
 abcdefghijklmnopqrstuvwxyz
 10
 1234567890abcdef
 0
 Content-MD5: ...
 [blank line]

triggers HttpRequestDecoder to generate 3 objects:

An HttpRequest,
The first HttpContent whose content is 'abcdefghijklmnopqrstuvwxyz',
The second LastHttpContent whose content is '1234567890abcdef', which marks the end of the content.

If you prefer not to handle HttpContents by yourself for your convenience, insert HttpObjectAggregator after this decoder in the ChannelPipeline. However, please note that your server might not be as memory efficient as without the aggregator.

Extensibility

Please note that this decoder is designed to be extended to implement a protocol derived from HTTP, such as RTSP and ICAP. To implement the decoder of such a derived protocol, extend this class and implement all abstract methods properly.

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
Modifier and Type	Field and Description
`static boolean`	`DEFAULT_ALLOW_DUPLICATE_CONTENT_LENGTHS`
`static boolean`	`DEFAULT_ALLOW_PARTIAL_CHUNKS`
`static boolean`	`DEFAULT_CHUNKED_SUPPORTED`
`static int`	`DEFAULT_INITIAL_BUFFER_SIZE`
`static int`	`DEFAULT_MAX_CHUNK_SIZE`
`static int`	`DEFAULT_MAX_HEADER_SIZE`
`static int`	`DEFAULT_MAX_INITIAL_LINE_LENGTH`
`static boolean`	`DEFAULT_VALIDATE_HEADERS`
`protected boolean`	`validateHeaders`

Fields inherited from class io.netty.handler.codec.ByteToMessageDecoder
COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`HttpObjectDecoder()` Creates a new instance with the default `maxInitialLineLength (4096`}, `maxHeaderSize (8192)`, and `maxChunkSize (8192)`.
`protected`	`HttpObjectDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean chunkedSupported)` Creates a new instance with the specified parameters.
`protected`	`HttpObjectDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean chunkedSupported, boolean validateHeaders)` Creates a new instance with the specified parameters.
`protected`	`HttpObjectDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean chunkedSupported, boolean validateHeaders, int initialBufferSize)` Creates a new instance with the specified parameters.
`protected`	`HttpObjectDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean chunkedSupported, boolean validateHeaders, int initialBufferSize, boolean allowDuplicateContentLengths)` Creates a new instance with the specified parameters.
`protected`	`HttpObjectDecoder(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean chunkedSupported, boolean validateHeaders, int initialBufferSize, boolean allowDuplicateContentLengths, boolean allowPartialChunks)` Creates a new instance with the specified parameters.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`protected abstract HttpMessage`	`createInvalidMessage()`
`protected abstract HttpMessage`	`createMessage(String[] initialLine)`
`protected void`	`decode(ChannelHandlerContext ctx, ByteBuf buffer, List<Object> out)` Decode the from one `ByteBuf` to an other.
`protected void`	`decodeLast(ChannelHandlerContext ctx, ByteBuf in, List<Object> out)` Is called one last time when the `ChannelHandlerContext` goes in-active.
`protected void`	`handleTransferEncodingChunkedWithContentLength(HttpMessage message)` Invoked when a message with both a "Transfer-Encoding: chunked" and a "Content-Length" header field is detected.
`protected boolean`	`isContentAlwaysEmpty(HttpMessage msg)`
`protected abstract boolean`	`isDecodingRequest()`
`protected boolean`	`isSwitchingToNonHttp1Protocol(HttpResponse msg)` Returns true if the server switched to a different protocol than HTTP/1.0 or HTTP/1.1, e.g.
`void`	`reset()` Resets the state of the decoder so that it is ready to decode a new message.
`void`	`userEventTriggered(ChannelHandlerContext ctx, Object evt)` Calls `ChannelHandlerContext.fireUserEventTriggered(Object)` to forward to the next `ChannelInboundHandler` in the `ChannelPipeline`.

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

Field Detail
- DEFAULT_MAX_INITIAL_LINE_LENGTH
```
public static final int DEFAULT_MAX_INITIAL_LINE_LENGTH
```
  See Also:
  
  Constant Field Values
- DEFAULT_MAX_HEADER_SIZE
```
public static final int DEFAULT_MAX_HEADER_SIZE
```
  See Also:
  
  Constant Field Values
- DEFAULT_CHUNKED_SUPPORTED
```
public static final boolean DEFAULT_CHUNKED_SUPPORTED
```
  See Also:
  
  Constant Field Values
- DEFAULT_ALLOW_PARTIAL_CHUNKS
```
public static final boolean DEFAULT_ALLOW_PARTIAL_CHUNKS
```
  See Also:
  
  Constant Field Values
- DEFAULT_MAX_CHUNK_SIZE
```
public static final int DEFAULT_MAX_CHUNK_SIZE
```
  See Also:
  
  Constant Field Values
- DEFAULT_VALIDATE_HEADERS
```
public static final boolean DEFAULT_VALIDATE_HEADERS
```
  See Also:
  
  Constant Field Values
- DEFAULT_INITIAL_BUFFER_SIZE
```
public static final int DEFAULT_INITIAL_BUFFER_SIZE
```
  See Also:
  
  Constant Field Values
- DEFAULT_ALLOW_DUPLICATE_CONTENT_LENGTHS
```
public static final boolean DEFAULT_ALLOW_DUPLICATE_CONTENT_LENGTHS
```
  See Also:
  
  Constant Field Values
- validateHeaders
```
protected final boolean validateHeaders
```