org.springframework.http.codec.protobuf

Class ProtobufEncoder

java.lang.Object

org.springframework.http.codec.protobuf.ProtobufCodecSupport

org.springframework.http.codec.protobuf.ProtobufEncoder

All Implemented Interfaces:

Encoder<com.google.protobuf.Message>, HttpMessageEncoder<com.google.protobuf.Message>

public class ProtobufEncoder
extends ProtobufCodecSupport
implements HttpMessageEncoder<com.google.protobuf.Message>

An Encoder that writes Messages using Google Protocol Buffers.

Flux are serialized using delimited Protobuf messages with the size of each message specified before the message itself. Single values are serialized using regular Protobuf message format (without the size prepended before the message).

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

This encoder 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:

ProtobufDecoder

Constructor Summary

Constructors

Constructor and Description
ProtobufEncoder()

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.
reactor.core.publisher.Flux<DataBuffer>	encode(Publisher<? extends com.google.protobuf.Message> 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(com.google.protobuf.Message message, DataBufferFactory bufferFactory, ResolvableType valueType, MimeType mimeType, Map<String,Object> hints) Encode an Object of type T to a data buffer.
List<MimeType>	getEncodableMimeTypes() Return the list of MIME types supported by this Encoder.
List<MediaType>	getStreamingMediaTypes() Return "streaming" media types for which flushing should be performed automatically vs at the end of the input stream.

Methods inherited from class org.springframework.http.codec.protobuf.ProtobufCodecSupport

getMimeTypes, supportsMimeType

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.http.codec.HttpMessageEncoder

getEncodeHints

Methods inherited from interface org.springframework.core.codec.Encoder

getEncodableMimeTypes

Constructor Detail

ProtobufEncoder

public ProtobufEncoder()

Method Detail

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<com.google.protobuf.Message>

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<? extends com.google.protobuf.Message> 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<com.google.protobuf.Message>

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(com.google.protobuf.Message message,
                              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 (e.g. encoding a Resource).

Specified by:

encodeValue in interface Encoder<com.google.protobuf.Message>

Parameters:

message - 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

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<com.google.protobuf.Message>

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<com.google.protobuf.Message>

Returns:

the list of supported MIME types