Package org.springframework.http.converter.protobuf

Class ProtobufHttpMessageConverter

java.lang.Object

org.springframework.http.converter.AbstractHttpMessageConverter<com.google.protobuf.Message>

org.springframework.http.converter.protobuf.ProtobufHttpMessageConverter

All Implemented Interfaces:

HttpMessageConverter<com.google.protobuf.Message>

Direct Known Subclasses:

ProtobufJsonFormatHttpMessageConverter

public class ProtobufHttpMessageConverter
extends AbstractHttpMessageConverter<com.google.protobuf.Message>

An HttpMessageConverter that reads and writes com.google.protobuf.Messages using Google Protocol Buffers.

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

This converter supports by default "application/x-protobuf" and "text/plain" with the official "com.google.protobuf:protobuf-java" library. The "application/json" format is also supported with the "com.google.protobuf:protobuf-java-util" dependency. See ProtobufJsonFormatHttpMessageConverter for a configurable variant.

This converter requires Protobuf 3 or higher as of Spring Framework 6.1.

Since:

4.1

Author:

Alex Antonov, Brian Clozel, Juergen Hoeller, Sebastien Deleuze

See Also:

• JsonFormat
• ProtobufJsonFormatHttpMessageConverter

Field Summary

Fields

Modifier and Type	Field	Description
static final Charset	DEFAULT_CHARSET	The default charset used by the converter.
static final MediaType	PROTOBUF	The media-type for protobuf application/x-protobuf.
static final String	X_PROTOBUF_MESSAGE_HEADER	The HTTP header containing the protobuf message.
static final String	X_PROTOBUF_SCHEMA_HEADER	The HTTP header containing the protobuf schema.

Fields inherited from class org.springframework.http.converter.AbstractHttpMessageConverter

logger

Constructor Summary

Constructors

Constructor	Description
ProtobufHttpMessageConverter()	Construct a new ProtobufHttpMessageConverter.
ProtobufHttpMessageConverter(com.google.protobuf.ExtensionRegistry extensionRegistry)	Construct a new ProtobufHttpMessageConverter with a registry that specifies protocol message extensions.

Method Summary

Modifier and Type	Method	Description
protected boolean	canWrite(MediaType mediaType)	Returns true if the given media type includes any of the supported media types.
protected MediaType	getDefaultContentType(com.google.protobuf.Message message)	Returns the default content type for the given type.
protected com.google.protobuf.Message	readInternal(Class<? extends com.google.protobuf.Message> clazz, HttpInputMessage inputMessage)	Abstract template method that reads the actual object.
protected boolean	supports(Class<?> clazz)	Indicates whether the given class is supported by this converter.
protected boolean	supportsRepeatableWrites(com.google.protobuf.Message message)	Indicates whether this message converter can write the given object multiple times.
protected void	writeInternal(com.google.protobuf.Message message, HttpOutputMessage outputMessage)	Abstract template method that writes the actual body.

Methods inherited from class org.springframework.http.converter.AbstractHttpMessageConverter

addDefaultHeaders, canRead, canRead, canWrite, getContentLength, getDefaultCharset, getSupportedMediaTypes, read, setDefaultCharset, setSupportedMediaTypes, write

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.converter.HttpMessageConverter

getSupportedMediaTypes

Field Details

DEFAULT_CHARSET

public static final Charset DEFAULT_CHARSET

The default charset used by the converter.

PROTOBUF

public static final MediaType PROTOBUF

The media-type for protobuf application/x-protobuf.

X_PROTOBUF_SCHEMA_HEADER

public static final String X_PROTOBUF_SCHEMA_HEADER

The HTTP header containing the protobuf schema.

See Also:

• Constant Field Values

X_PROTOBUF_MESSAGE_HEADER

public static final String X_PROTOBUF_MESSAGE_HEADER

The HTTP header containing the protobuf message.

See Also:

• Constant Field Values

Constructor Details

ProtobufHttpMessageConverter

public ProtobufHttpMessageConverter()

Construct a new ProtobufHttpMessageConverter.

ProtobufHttpMessageConverter

public ProtobufHttpMessageConverter(com.google.protobuf.ExtensionRegistry extensionRegistry)

Construct a new ProtobufHttpMessageConverter with a registry that specifies protocol message extensions.

Parameters:

extensionRegistry - the registry to populate

Method Details

supports

protected boolean supports(Class<?> clazz)

Description copied from class: AbstractHttpMessageConverter

Indicates whether the given class is supported by this converter.

Specified by:

supports in class AbstractHttpMessageConverter<com.google.protobuf.Message>

Parameters:

clazz - the class to test for support

Returns:

true if supported; false otherwise

getDefaultContentType

protected MediaType getDefaultContentType(com.google.protobuf.Message message)

Description copied from class: AbstractHttpMessageConverter

Returns the default content type for the given type. Called when AbstractHttpMessageConverter.write(T, org.springframework.http.MediaType, org.springframework.http.HttpOutputMessage) is invoked without a specified content type parameter.

By default, this returns the first element of the supportedMediaTypes property, if any. Can be overridden in subclasses.

Overrides:

getDefaultContentType in class AbstractHttpMessageConverter<com.google.protobuf.Message>

Parameters:

message - the type to return the content type for

Returns:

the content type, or null if not known

readInternal

protected com.google.protobuf.Message readInternal(Class<? extends com.google.protobuf.Message> clazz,
 HttpInputMessage inputMessage)
                                            throws IOException,
HttpMessageNotReadableException

Description copied from class: AbstractHttpMessageConverter

Abstract template method that reads the actual object. Invoked from AbstractHttpMessageConverter.read(java.lang.Class<? extends T>, org.springframework.http.HttpInputMessage).

Specified by:

readInternal in class AbstractHttpMessageConverter<com.google.protobuf.Message>

Parameters:

clazz - the type of object to return

inputMessage - the HTTP input message to read from

Returns:

the converted object

Throws:

IOException - in case of I/O errors

HttpMessageNotReadableException - in case of conversion errors

canWrite

protected boolean canWrite(@Nullable
 MediaType mediaType)

Description copied from class: AbstractHttpMessageConverter

Returns true if the given media type includes any of the supported media types.

Overrides:

canWrite in class AbstractHttpMessageConverter<com.google.protobuf.Message>

Parameters:

mediaType - the media type to write, can be null if not specified. Typically the value of an Accept header.

Returns:

true if the supported media types are compatible with the media type, or if the media type is null

writeInternal

protected void writeInternal(com.google.protobuf.Message message,
 HttpOutputMessage outputMessage)
                      throws IOException,
HttpMessageNotWritableException

Description copied from class: AbstractHttpMessageConverter

Abstract template method that writes the actual body. Invoked from AbstractHttpMessageConverter.write(T, org.springframework.http.MediaType, org.springframework.http.HttpOutputMessage).

Specified by:

writeInternal in class AbstractHttpMessageConverter<com.google.protobuf.Message>

Parameters:

message - the object to write to the output message

outputMessage - the HTTP output message to write to

Throws:

IOException - in case of I/O errors

HttpMessageNotWritableException - in case of conversion errors

supportsRepeatableWrites

protected boolean supportsRepeatableWrites(com.google.protobuf.Message message)

Description copied from class: AbstractHttpMessageConverter

Indicates whether this message converter can write the given object multiple times.

Default implementation returns false.

Overrides:

supportsRepeatableWrites in class AbstractHttpMessageConverter<com.google.protobuf.Message>

Parameters:

message - the object t

Returns:

true if t can be written repeatedly; false otherwise