org.springframework.http.codec.json

Class AbstractJackson2Decoder

java.lang.Object

org.springframework.http.codec.json.Jackson2CodecSupport

org.springframework.http.codec.json.AbstractJackson2Decoder

All Implemented Interfaces:

Decoder<Object>, HttpMessageDecoder<Object>

Direct Known Subclasses:

Jackson2CborDecoder, Jackson2JsonDecoder, Jackson2SmileDecoder

public abstract class AbstractJackson2Decoder
extends Jackson2CodecSupport
implements HttpMessageDecoder<Object>

Abstract base class for Jackson 2.9 decoding, leveraging non-blocking parsing.

Compatible with Jackson 2.9.7 and higher.

Since:

5.0

Author:

Sebastien Deleuze, Rossen Stoyanchev, Arjen Poutsma

See Also:

Add support for non-blocking ("async") JSON parsing

Field Summary

Fields inherited from class org.springframework.http.codec.json.Jackson2CodecSupport

JSON_VIEW_HINT, logger

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractJackson2Decoder(ObjectMapper mapper, MimeType... mimeTypes) Constructor with a Jackson ObjectMapper to use.

Method Summary

Modifier and Type	Method and Description
boolean	canDecode(ResolvableType elementType, MimeType mimeType) Whether the decoder supports the given target element type and the MIME type of the source stream.
Object	decode(DataBuffer dataBuffer, ResolvableType targetType, MimeType mimeType, Map<String,Object> hints) Decode a data buffer to an Object of type T.
reactor.core.publisher.Flux<Object>	decode(Publisher<DataBuffer> input, ResolvableType elementType, MimeType mimeType, Map<String,Object> hints) Decode a DataBuffer input stream into a Flux of T.
reactor.core.publisher.Mono<Object>	decodeToMono(Publisher<DataBuffer> input, ResolvableType elementType, MimeType mimeType, Map<String,Object> hints) Decode a DataBuffer input stream into a Mono of T.
protected <A extends Annotation> A	getAnnotation(MethodParameter parameter, Class<A> annotType)
List<MimeType>	getDecodableMimeTypes() Return the list of MIME types supported by this Decoder.
List<MimeType>	getDecodableMimeTypes(ResolvableType targetType) Return the list of MIME types supported by this Decoder for the given type of element.
Map<String,Object>	getDecodeHints(ResolvableType actualType, ResolvableType elementType, ServerHttpRequest request, ServerHttpResponse response) Get decoding hints based on the server request or annotations on the target controller method parameter.
int	getMaxInMemorySize() Return the configured byte count limit.
protected reactor.core.publisher.Flux<DataBuffer>	processInput(Publisher<DataBuffer> input, ResolvableType elementType, MimeType mimeType, Map<String,Object> hints) Process the input publisher into a flux.
void	setMaxInMemorySize(int byteCount) Set the max number of bytes that can be buffered by this decoder.

Methods inherited from class org.springframework.http.codec.json.Jackson2CodecSupport

getHints, getJavaType, getMimeTypes, getMimeTypes, getObjectMapper, getObjectMapperRegistrations, getObjectMappersForType, getParameter, logWarningIfNecessary, registerObjectMappersForType, selectObjectMapper, setObjectMapper, supportsMimeType

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractJackson2Decoder

protected AbstractJackson2Decoder(ObjectMapper mapper,
                                  MimeType... mimeTypes)

Constructor with a Jackson ObjectMapper to use.

Method Detail

setMaxInMemorySize

public void setMaxInMemorySize(int byteCount)

Set the max number of bytes that can be buffered by this decoder. This is either the size of the entire input when decoding as a whole, or the size of one top-level JSON object within a JSON stream. When the limit is exceeded, DataBufferLimitException is raised.

By default this is set to 256K.

Parameters:

byteCount - the max number of bytes to buffer, or -1 for unlimited

Since:

5.1.11

getMaxInMemorySize

public int getMaxInMemorySize()

Return the configured byte count limit.

Since:

5.1.11

canDecode

public boolean canDecode(ResolvableType elementType,
                         @Nullable
                         MimeType mimeType)

Description copied from interface: Decoder

Whether the decoder supports the given target element type and the MIME type of the source stream.

Specified by:

canDecode in interface Decoder<Object>

Parameters:

elementType - the target element type for the output stream

mimeType - the mime type associated with the stream to decode (can be null if not specified)

Returns:

true if supported, false otherwise

decode

public reactor.core.publisher.Flux<Object> decode(Publisher<DataBuffer> input,
                                                  ResolvableType elementType,
                                                  @Nullable
                                                  MimeType mimeType,
                                                  @Nullable
                                                  Map<String,Object> hints)

Description copied from interface: Decoder

Decode a DataBuffer input stream into a Flux of T.

Specified by:

decode in interface Decoder<Object>

Parameters:

input - the DataBuffer input stream to decode

elementType - the expected type of elements in the output stream; this type must have been previously passed to the Decoder.canDecode(org.springframework.core.ResolvableType, org.springframework.util.MimeType) method and it must have returned true.

mimeType - the MIME type associated with the input stream (optional)

hints - additional information about how to do decode

Returns:

the output stream with decoded elements

processInput

protected reactor.core.publisher.Flux<DataBuffer> processInput(Publisher<DataBuffer> input,
                                                               ResolvableType elementType,
                                                               @Nullable
                                                               MimeType mimeType,
                                                               @Nullable
                                                               Map<String,Object> hints)

Process the input publisher into a flux. Default implementation returns Flux.from(Publisher), but subclasses can choose to customize this behavior.

Parameters:

input - the DataBuffer input stream to process

elementType - the expected type of elements in the output stream

mimeType - the MIME type associated with the input stream (optional)

hints - additional information about how to do encode

Returns:

the processed flux

Since:

5.1.14

decodeToMono

public reactor.core.publisher.Mono<Object> decodeToMono(Publisher<DataBuffer> input,
                                                        ResolvableType elementType,
                                                        @Nullable
                                                        MimeType mimeType,
                                                        @Nullable
                                                        Map<String,Object> hints)

Description copied from interface: Decoder

Decode a DataBuffer input stream into a Mono of T.

Specified by:

decodeToMono in interface Decoder<Object>

Parameters:

input - the DataBuffer input stream to decode

elementType - the expected type of elements in the output stream; this type must have been previously passed to the Decoder.canDecode(org.springframework.core.ResolvableType, org.springframework.util.MimeType) method and it must have returned true.

mimeType - the MIME type associated with the input stream (optional)

hints - additional information about how to do decode

Returns:

the output stream with the decoded element

decode

public Object decode(DataBuffer dataBuffer,
                     ResolvableType targetType,
                     @Nullable
                     MimeType mimeType,
                     @Nullable
                     Map<String,Object> hints)
              throws DecodingException

Description copied from interface: Decoder

Decode a data buffer to an Object of type T. This is useful for scenarios, that distinct messages (or events) are decoded and handled individually, in fully aggregated form.

Specified by:

decode in interface Decoder<Object>

Parameters:

dataBuffer - the DataBuffer to decode

targetType - the expected output type

mimeType - the MIME type associated with the data

hints - additional information about how to do decode

Returns:

the decoded value, possibly null

Throws:

DecodingException

getDecodeHints

public Map<String,Object> getDecodeHints(ResolvableType actualType,
                                         ResolvableType elementType,
                                         ServerHttpRequest request,
                                         ServerHttpResponse response)

Description copied from interface: HttpMessageDecoder

Get decoding hints based on the server request or annotations on the target controller method parameter.

Specified by:

getDecodeHints in interface HttpMessageDecoder<Object>

Parameters:

actualType - the actual target type to decode to, possibly a reactive wrapper and sourced from MethodParameter, i.e. providing access to method parameter annotations

elementType - the element type within Flux/Mono that we're trying to decode to

request - the current request

response - the current response

Returns:

a Map with hints, possibly empty

getDecodableMimeTypes

public List<MimeType> getDecodableMimeTypes()

Description copied from interface: Decoder

Return the list of MIME types supported by this Decoder. The list may not apply to every possible target element type and calls to this method should typically be guarded via canDecode(elementType, null). The list may also exclude MIME types supported only for a specific element type. Alternatively, use Decoder.getDecodableMimeTypes(ResolvableType) for a more precise list.

Specified by:

getDecodableMimeTypes in interface Decoder<Object>

Returns:

the list of supported MIME types

getDecodableMimeTypes

public List<MimeType> getDecodableMimeTypes(ResolvableType targetType)

Description copied from interface: Decoder

Return the list of MIME types supported by this Decoder for the given type of element. This list may differ from Decoder.getDecodableMimeTypes() if the Decoder doesn't support the given element type or if it supports it only for a subset of MIME types.

Specified by:

getDecodableMimeTypes in interface Decoder<Object>

Parameters:

targetType - the type of element to check for decoding

Returns:

the list of MIME types supported for the given target type

getAnnotation

protected <A extends Annotation> A getAnnotation(MethodParameter parameter,
                                                 Class<A> annotType)

Specified by:

getAnnotation in class Jackson2CodecSupport