org.springframework.core.codec

Interface Decoder<T>

Type Parameters:

T - the type of elements in the output stream

All Known Subinterfaces:

HttpMessageDecoder<T>

All Known Implementing Classes:

AbstractDataBufferDecoder, AbstractDecoder, AbstractJackson2Decoder, ByteArrayDecoder, ByteBufferDecoder, DataBufferDecoder, Jackson2CborDecoder, Jackson2JsonDecoder, Jackson2SmileDecoder, Jaxb2XmlDecoder, KotlinSerializationJsonDecoder, NettyByteBufDecoder, ProtobufDecoder, ResourceDecoder, StringDecoder, XmlEventDecoder

public interface Decoder<T>

Strategy for decoding a DataBuffer input stream into an output stream of elements of type <T>.

Since:

5.0

Author:

Sebastien Deleuze, Rossen Stoyanchev

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.
default T	decode(DataBuffer buffer, ResolvableType targetType, MimeType mimeType, Map<String,Object> hints) Decode a data buffer to an Object of type T.
reactor.core.publisher.Flux<T>	decode(Publisher<DataBuffer> inputStream, ResolvableType elementType, MimeType mimeType, Map<String,Object> hints) Decode a DataBuffer input stream into a Flux of T.
reactor.core.publisher.Mono<T>	decodeToMono(Publisher<DataBuffer> inputStream, ResolvableType elementType, MimeType mimeType, Map<String,Object> hints) Decode a DataBuffer input stream into a Mono of T.
List<MimeType>	getDecodableMimeTypes() Return the list of MIME types supported by this Decoder.
default List<MimeType>	getDecodableMimeTypes(ResolvableType targetType) Return the list of MIME types supported by this Decoder for the given type of element.

Method Detail

canDecode

boolean canDecode(ResolvableType elementType,
                  @Nullable
                  MimeType mimeType)

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

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

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

Decode a DataBuffer input stream into a Flux of T.

Parameters:

inputStream - 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 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

decodeToMono

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

Decode a DataBuffer input stream into a Mono of T.

Parameters:

inputStream - 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 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

@Nullable
default T decode(DataBuffer buffer,
                           ResolvableType targetType,
                           @Nullable
                           MimeType mimeType,
                           @Nullable
                           Map<String,Object> hints)
                    throws DecodingException

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.

Parameters:

buffer - 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

Since:

5.2

getDecodableMimeTypes

List<MimeType> getDecodableMimeTypes()

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 getDecodableMimeTypes(ResolvableType) for a more precise list.

Returns:

the list of supported MIME types

getDecodableMimeTypes

default List<MimeType> getDecodableMimeTypes(ResolvableType targetType)

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

Parameters:

targetType - the type of element to check for decoding

Returns:

the list of MIME types supported for the given target type

Since:

5.3.4