org.springframework.http.codec.json

Class AbstractJackson2Encoder

java.lang.Object

org.springframework.http.codec.json.Jackson2CodecSupport

org.springframework.http.codec.json.AbstractJackson2Encoder

All Implemented Interfaces:

Encoder<Object>, HttpMessageEncoder<Object>

Direct Known Subclasses:

Jackson2CborEncoder, Jackson2JsonEncoder, Jackson2SmileEncoder

public abstract class AbstractJackson2Encoder
extends Jackson2CodecSupport
implements HttpMessageEncoder<Object>

Base class providing support methods for Jackson 2.9 encoding. For non-streaming use cases, Flux elements are collected into a List before serialization for performance reason.

Since:

5.0

Author:

Sebastien Deleuze, Arjen Poutsma

Field Summary

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

JSON_VIEW_HINT, logger

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractJackson2Encoder(ObjectMapper mapper, MimeType... mimeTypes) Constructor with a Jackson ObjectMapper to use.

Method Summary

Modifier and Type	Method and Description
boolean	canEncode(ResolvableType elementType, MimeType mimeType) Whether the encoder supports the given source element type and the MIME type for the output stream.
protected ObjectWriter	customizeWriter(ObjectWriter writer, MimeType mimeType, ResolvableType elementType, Map<String,Object> hints)
reactor.core.publisher.Flux<DataBuffer>	encode(org.reactivestreams.Publisher<?> inputStream, DataBufferFactory bufferFactory, ResolvableType elementType, MimeType mimeType, Map<String,Object> hints) Encode a stream of Objects of type T into a DataBuffer output stream.
DataBuffer	encodeValue(Object value, DataBufferFactory bufferFactory, ResolvableType valueType, MimeType mimeType, Map<String,Object> hints) Encode an Object of type T to a data buffer.
protected <A extends Annotation> A	getAnnotation(MethodParameter parameter, Class<A> annotType)
List<MimeType>	getEncodableMimeTypes() Return the list of mime types this encoder supports.
Map<String,Object>	getEncodeHints(ResolvableType actualType, ResolvableType elementType, MediaType mediaType, ServerHttpRequest request, ServerHttpResponse response) Get decoding hints based on the server request or annotations on the target controller method parameter.
protected JsonEncoding	getJsonEncoding(MimeType mimeType) Determine the JSON encoding to use for the given mime type.
List<MediaType>	getStreamingMediaTypes() Return "streaming" media types for which flushing should be performed automatically vs at the end of the input stream.
void	setStreamingMediaTypes(List<MediaType> mediaTypes) Configure "streaming" media types for which flushing should be performed automatically vs at the end of the stream.

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

getHints, getJavaType, getMimeTypes, getObjectMapper, getParameter, supportsMimeType

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractJackson2Encoder

protected AbstractJackson2Encoder(ObjectMapper mapper,
                                  MimeType... mimeTypes)

Constructor with a Jackson ObjectMapper to use.

Method Detail

setStreamingMediaTypes

public void setStreamingMediaTypes(List<MediaType> mediaTypes)

Configure "streaming" media types for which flushing should be performed automatically vs at the end of the stream.

By default this is set to MediaType.APPLICATION_STREAM_JSON.

Parameters:

mediaTypes - one or more media types to add to the list

See Also:

HttpMessageEncoder.getStreamingMediaTypes()

canEncode

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

Description copied from interface: Encoder

Whether the encoder supports the given source element type and the MIME type for the output stream.

Specified by:

canEncode in interface Encoder<Object>

Parameters:

elementType - the type of elements in the source stream

mimeType - the MIME type for the output stream (can be null if not specified)

Returns:

true if supported, false otherwise

encode

public reactor.core.publisher.Flux<DataBuffer> encode(org.reactivestreams.Publisher<?> inputStream,
                                                      DataBufferFactory bufferFactory,
                                                      ResolvableType elementType,
                                                      @Nullable
                                                      MimeType mimeType,
                                                      @Nullable
                                                      Map<String,Object> hints)

Description copied from interface: Encoder

Encode a stream of Objects of type T into a DataBuffer output stream.

Specified by:

encode in interface Encoder<Object>

Parameters:

inputStream - the input stream of Objects to encode. If the input should be encoded as a single value rather than as a stream of elements, an instance of Mono should be used.

bufferFactory - for creating output stream DataBuffer's

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

mimeType - the MIME type for the output content (optional)

hints - additional information about how to encode

Returns:

the output stream

encodeValue

public DataBuffer encodeValue(Object value,
                              DataBufferFactory bufferFactory,
                              ResolvableType valueType,
                              @Nullable
                              MimeType mimeType,
                              @Nullable
                              Map<String,Object> hints)

Description copied from interface: Encoder

Encode an Object of type T to a data buffer. This is useful for scenarios that produce a stream of discrete messages (or events) and the content for each is encoded individually.

By default this method raises UnsupportedOperationException and it is expected that some encoders cannot produce a single buffer or cannot do so synchronously (e.g. encoding a Resource).

Specified by:

encodeValue in interface Encoder<Object>

Parameters:

value - the value to be encoded

bufferFactory - for creating the output DataBuffer

valueType - the type for the value being encoded

mimeType - the MIME type for the output content (optional)

hints - additional information about how to encode

Returns:

the encoded content

customizeWriter

protected ObjectWriter customizeWriter(ObjectWriter writer,
                                       @Nullable
                                       MimeType mimeType,
                                       ResolvableType elementType,
                                       @Nullable
                                       Map<String,Object> hints)

getJsonEncoding

protected JsonEncoding getJsonEncoding(@Nullable
                                       MimeType mimeType)

Determine the JSON encoding to use for the given mime type.

Parameters:

mimeType - the mime type as requested by the caller

Returns:

the JSON encoding to use (never null)

Since:

5.0.5

getEncodableMimeTypes

public List<MimeType> getEncodableMimeTypes()

Description copied from interface: Encoder

Return the list of mime types this encoder supports.

Specified by:

getEncodableMimeTypes in interface Encoder<Object>

getStreamingMediaTypes

public List<MediaType> getStreamingMediaTypes()

Description copied from interface: HttpMessageEncoder

Return "streaming" media types for which flushing should be performed automatically vs at the end of the input stream.

Specified by:

getStreamingMediaTypes in interface HttpMessageEncoder<Object>

getEncodeHints

public Map<String,Object> getEncodeHints(@Nullable
                                         ResolvableType actualType,
                                         ResolvableType elementType,
                                         @Nullable
                                         MediaType mediaType,
                                         ServerHttpRequest request,
                                         ServerHttpResponse response)

Description copied from interface: HttpMessageEncoder

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

Specified by:

getEncodeHints in interface HttpMessageEncoder<Object>

Parameters:

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

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

request - the current request

response - the current response

Returns:

a Map with hints, possibly empty

getAnnotation

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

Specified by:

getAnnotation in class Jackson2CodecSupport