org.springframework.http.codec.protobuf

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:

ProtobufEncoder

Field Summary

Fields

Modifier and Type	Field and Description
protected static int	DEFAULT_MESSAGE_MAX_SIZE The default max size for aggregating messages.

Constructor Summary

Constructors

Constructor and Description
ProtobufDecoder() Construct a new ProtobufDecoder.
ProtobufDecoder(com.google.protobuf.ExtensionRegistry extensionRegistry) Construct a new ProtobufDecoder with an initializer that allows the registration of message extensions.

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.
com.google.protobuf.Message	decode(DataBuffer dataBuffer, ResolvableType targetType, MimeType mimeType, Map<String,Object> hints) Decode a data buffer to an Object of type T.
reactor.core.publisher.Flux<com.google.protobuf.Message>	decode(org.reactivestreams.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<com.google.protobuf.Message>	decodeToMono(org.reactivestreams.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.
int	getMaxMessageSize() Return the configured message size limit.
void	setMaxMessageSize(int maxMessageSize) The max size allowed per message.

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.core.codec.Decoder

getDecodableMimeTypes

Field Detail

DEFAULT_MESSAGE_MAX_SIZE

protected static final int DEFAULT_MESSAGE_MAX_SIZE

The default max size for aggregating messages.

See Also:

Constant Field Values

Constructor Detail

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 Detail

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(org.reactivestreams.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(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

public reactor.core.publisher.Mono<com.google.protobuf.Message> decodeToMono(org.reactivestreams.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(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

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