Package 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.x encoding. For non-streaming use cases, Flux elements are collected into a List before serialization for performance reasons.
Since:
5.0
Author:
Sebastien Deleuze, Arjen Poutsma

  • Constructor Details

    • AbstractJackson2Encoder

      protected AbstractJackson2Encoder(com.fasterxml.jackson.databind.ObjectMapper mapper, MimeType... mimeTypes)
      Constructor with a Jackson ObjectMapper to use.

  • Method Details

    • 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.

    • 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(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 distinct messages (or events) are encoded and handled individually, in fully aggregated form.

      By default this method raises UnsupportedOperationException and it is expected that some encoders cannot produce a single buffer or cannot do so synchronously (for example, 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 com.fasterxml.jackson.databind.ObjectWriter customizeWriter(com.fasterxml.jackson.databind.ObjectWriter writer, @Nullable MimeType mimeType, ResolvableType elementType, @Nullable Map<String,Object> hints)
      Subclasses can use this method to customize the ObjectWriter used for writing values.
      Parameters:
      writer - the writer instance to customize
      mimeType - the selected MIME type
      elementType - the type of element values to write
      hints - a map with serialization hints; the Reactor Context, when available, may be accessed under the key ContextView.class.getName()
      Returns:
      the customized ObjectWriter to use

    • getStreamingMediaTypeSeparator

      protected byte @Nullable [] getStreamingMediaTypeSeparator(@Nullable MimeType mimeType)
      Return the separator to use for the given mime type.

      By default, this method returns new line "\n" if the given mime type is one of the configured streaming mime types.

      Since:
      5.3

    • getJsonEncoding

      protected com.fasterxml.jackson.core.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 supported by this Encoder. The list may not apply to every possible target element type and calls to this method should typically be guarded via canEncode(elementType, null). The list may also exclude MIME types supported only for a specific element type. Alternatively, use Encoder.getEncodableMimeTypes(ResolvableType) for a more precise list.
      Specified by:
      getEncodableMimeTypes in interface Encoder<Object>
      Returns:
      the list of supported MIME types

    • getEncodableMimeTypes

      public List<MimeType> getEncodableMimeTypes(ResolvableType elementType)
      Description copied from interface: Encoder
      Return the list of MIME types supported by this Encoder for the given type of element. This list may differ from the Encoder.getEncodableMimeTypes() if the Encoder doesn't support the element type or if it supports it only for a subset of MIME types.
      Specified by:
      getEncodableMimeTypes in interface Encoder<Object>
      Parameters:
      elementType - the type of element to check for encoding
      Returns:
      the list of MIME types supported for the given element type

    • 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> @Nullable A getAnnotation(MethodParameter parameter, Class<A> annotType)
      Specified by:
      getAnnotation in class Jackson2CodecSupport