Class ProtobufJsonDecoder

java.lang.Object
org.springframework.http.codec.protobuf.ProtobufJsonDecoder
All Implemented Interfaces:
Decoder<com.google.protobuf.Message>
public class ProtobufJsonDecoder extends Object implements Decoder<com.google.protobuf.Message>
A Decoder that reads a JSON byte stream and converts it to Google Protocol Buffers Messages.

Flux deserialized via decode(Publisher, ResolvableType, MimeType, Map) are not supported because the Protobuf Java Util library does not provide a non-blocking parser that splits a JSON stream into tokens. Applications should consider decoding to Mono<Message> or Mono<List<Message>>, which will use the supported decodeToMono(Publisher, ResolvableType, MimeType, Map).

To generate Message Java classes, you need to install the protoc binary.

This decoder requires Protobuf 3.29 or higher, and supports "application/json" and "application/*+json" with the official "com.google.protobuf:protobuf-java-util" library.

Since:
6.2
Author:
Brian Clozel
See Also:

  • Field Details

    • DEFAULT_MESSAGE_MAX_SIZE

      protected static final int DEFAULT_MESSAGE_MAX_SIZE
      The default max size for aggregating messages.
      See Also:

  • Constructor Details

    • ProtobufJsonDecoder

      public ProtobufJsonDecoder()
      Construct a new ProtobufJsonDecoder using a default JsonFormat.Parser instance.

    • ProtobufJsonDecoder

      public ProtobufJsonDecoder(com.google.protobuf.util.JsonFormat.Parser parser)
      Construct a new ProtobufJsonDecoder using the given JsonFormat.Parser instance.

  • Method Details

    • getMaxMessageSize

      public int getMaxMessageSize()
      Return the configured message size limit.

    • setMaxMessageSize

      public void setMaxMessageSize(int maxMessageSize)
      The max size allowed per message.

      By default, this is set to 256K.

      Parameters:
      maxMessageSize - the max size per message, or -1 for unlimited

    • 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<com.google.protobuf.Message>
      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

    • 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<com.google.protobuf.Message>
      Returns:
      the list of supported MIME types

    • decode

      public reactor.core.publisher.Flux<com.google.protobuf.Message> decode(Publisher<DataBuffer> inputStream, ResolvableType targetType, @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<com.google.protobuf.Message>
      Parameters:
      inputStream - the DataBuffer input stream to decode
      targetType - the expected type of elements in the output stream; this type must have been previously passed to the Decoder.canDecode(ResolvableType, 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

    • decode

      public com.google.protobuf.Message 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<com.google.protobuf.Message>
      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

    • decodeToMono

      public reactor.core.publisher.Mono<com.google.protobuf.Message> decodeToMono(Publisher<DataBuffer> inputStream, 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<com.google.protobuf.Message>
      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 Decoder.canDecode(ResolvableType, 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