Class ProtobufDecoder

java.lang.Object
org.springframework.http.codec.protobuf.ProtobufCodecSupport
org.springframework.http.codec.protobuf.ProtobufDecoder
All Implemented Interfaces:
Decoder<com.google.protobuf.Message>
public class ProtobufDecoder extends ProtobufCodecSupport implements Decoder<com.google.protobuf.Message>
A Decoder that reads Messages using Google Protocol Buffers.

Flux deserialized via decode(Publisher, ResolvableType, MimeType, Map) are expected to use delimited Protobuf messages with the size of each message specified before the message itself. Single values deserialized via decodeToMono(Publisher, ResolvableType, MimeType, Map) are expected to use regular Protobuf message format (without the size prepended before the message).

Notice that default instance of Protobuf message produces empty byte array, so Mono.just(Msg.getDefaultInstance()) sent over the network will be deserialized as an empty Mono.

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

This decoder requires Protobuf 3 or higher, and supports "application/x-protobuf" and "application/octet-stream" with the official "com.google.protobuf:protobuf-java" library.

Since:
5.1
Author:
Sebastien Deleuze
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

    • ProtobufDecoder

      public ProtobufDecoder()
      Construct a new ProtobufDecoder.

    • ProtobufDecoder

      public ProtobufDecoder(com.google.protobuf.ExtensionRegistry extensionRegistry)
      Construct a new ProtobufDecoder with an initializer that allows the registration of message extensions.
      Parameters:
      extensionRegistry - a message extension registry

  • Method Details

    • 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

    • getMaxMessageSize

      public int getMaxMessageSize()
      Return the configured message size 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<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

    • decode

      public reactor.core.publisher.Flux<com.google.protobuf.Message> decode(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 Flux of T.
      Specified by:
      decode 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 decoded elements

    • 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

    • 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

    • 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