Class ProtobufDecoder

java.lang.Object

org.springframework.http.codec.protobuf.ProtobufCodecSupport

org.springframework.http.codec.protobuf.ProtobufDecoder

All Implemented Interfaces:

org.springframework.core.codec.Decoder<com.google.protobuf.Message>

public class ProtobufDecoder
extends ProtobufCodecSupport
implements org.springframework.core.codec.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

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static interface	ProtobufDecoder.MessageSizeReader	Component to read the size of a message.

Field Summary

Fields

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

Fields inherited from class ProtobufCodecSupport

MIME_TYPES

Constructor Summary

Constructors

Constructor	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	Description
boolean	canDecode(org.springframework.core.ResolvableType elementType, @Nullable org.springframework.util.MimeType mimeType)
reactor.core.publisher.Flux<com.google.protobuf.Message>	decode(Publisher<org.springframework.core.io.buffer.DataBuffer> inputStream, org.springframework.core.ResolvableType elementType, @Nullable org.springframework.util.MimeType mimeType, @Nullable Map<String,Object> hints)
com.google.protobuf.Message	decode(org.springframework.core.io.buffer.DataBuffer dataBuffer, org.springframework.core.ResolvableType targetType, @Nullable org.springframework.util.MimeType mimeType, @Nullable Map<String,Object> hints)
reactor.core.publisher.Mono<com.google.protobuf.Message>	decodeToMono(Publisher<org.springframework.core.io.buffer.DataBuffer> inputStream, org.springframework.core.ResolvableType elementType, @Nullable org.springframework.util.MimeType mimeType, @Nullable Map<String,Object> hints)
List<org.springframework.util.MimeType>	getDecodableMimeTypes()
int	getMaxMessageSize()	Return the configured message size limit.
protected ProtobufDecoder.MessageSizeReader	initMessageSizeReader()	Return a reader for message size information encoded in the input stream.
protected void	merge(org.springframework.core.io.buffer.DataBuffer dataBuffer, com.google.protobuf.Message.Builder builder)	Use merge methods on Message.Builder to read a single message from the given DataBuffer.
void	setMaxMessageSize(int maxMessageSize)	The max size allowed per message.

Methods inherited from class ProtobufCodecSupport

getMimeTypes, setMimeTypes, supportsMimeType

Methods inherited from class Object

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

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

getDecodableMimeTypes

Field Details

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 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(org.springframework.core.ResolvableType elementType,
 @Nullable org.springframework.util.MimeType mimeType)

Specified by:

canDecode in interface org.springframework.core.codec.Decoder<com.google.protobuf.Message>

decode

public reactor.core.publisher.Flux<com.google.protobuf.Message> decode(Publisher<org.springframework.core.io.buffer.DataBuffer> inputStream,
 org.springframework.core.ResolvableType elementType,
 @Nullable org.springframework.util.MimeType mimeType,
 @Nullable Map<String,Object> hints)

Specified by:

decode in interface org.springframework.core.codec.Decoder<com.google.protobuf.Message>

initMessageSizeReader

protected ProtobufDecoder.MessageSizeReader initMessageSizeReader()

Return a reader for message size information encoded in the input stream.

Since:

7.0

decodeToMono

public reactor.core.publisher.Mono<com.google.protobuf.Message> decodeToMono(Publisher<org.springframework.core.io.buffer.DataBuffer> inputStream,
 org.springframework.core.ResolvableType elementType,
 @Nullable org.springframework.util.MimeType mimeType,
 @Nullable Map<String,Object> hints)

Specified by:

decodeToMono in interface org.springframework.core.codec.Decoder<com.google.protobuf.Message>

decode

public com.google.protobuf.Message decode(org.springframework.core.io.buffer.DataBuffer dataBuffer,
 org.springframework.core.ResolvableType targetType,
 @Nullable org.springframework.util.MimeType mimeType,
 @Nullable Map<String,Object> hints)
                                   throws org.springframework.core.codec.DecodingException

Specified by:

decode in interface org.springframework.core.codec.Decoder<com.google.protobuf.Message>

Throws:

org.springframework.core.codec.DecodingException

merge

protected void merge(org.springframework.core.io.buffer.DataBuffer dataBuffer,
 com.google.protobuf.Message.Builder builder)
              throws IOException

Use merge methods on Message.Builder to read a single message from the given DataBuffer.

Throws:

IOException

Since:

7.0

getDecodableMimeTypes

public List<org.springframework.util.MimeType> getDecodableMimeTypes()

Specified by:

getDecodableMimeTypes in interface org.springframework.core.codec.Decoder<com.google.protobuf.Message>