org.springframework.http.codec

Class EncoderHttpMessageWriter<T>

java.lang.Object

org.springframework.http.codec.EncoderHttpMessageWriter<T>

Type Parameters:

T - the type of objects in the input stream

All Implemented Interfaces:

HttpMessageWriter<T>

Direct Known Subclasses:

ProtobufHttpMessageWriter

public class EncoderHttpMessageWriter<T>
extends Object
implements HttpMessageWriter<T>

HttpMessageWriter that wraps and delegates to an Encoder.

Also a HttpMessageWriter that pre-resolves encoding hints from the extra information available on the server side such as the request or controller method annotations.

Since:

5.0

Author:

Arjen Poutsma, Sebastien Deleuze, Rossen Stoyanchev, Brian Clozel, Sam Brannen

Constructor Summary

Constructors

Constructor and Description
EncoderHttpMessageWriter(Encoder<T> encoder) Create an instance wrapping the given Encoder.

Method Summary

Modifier and Type	Method and Description
boolean	canWrite(ResolvableType elementType, MediaType mediaType) Whether the given object type is supported by this writer.
Encoder<T>	getEncoder() Return the Encoder of this writer.
List<MediaType>	getWritableMediaTypes() Return the list of media types supported by this Writer.
List<MediaType>	getWritableMediaTypes(ResolvableType elementType) Return the list of media types supported by this Writer for the given type of element.
protected Map<String,Object>	getWriteHints(ResolvableType streamType, ResolvableType elementType, MediaType mediaType, ServerHttpRequest request, ServerHttpResponse response) Get additional hints for encoding for example based on the server request or annotations from controller method parameters.
reactor.core.publisher.Mono<Void>	write(Publisher<? extends T> inputStream, ResolvableType elementType, MediaType mediaType, ReactiveHttpOutputMessage message, Map<String,Object> hints) Write a given stream of object to the output message.
reactor.core.publisher.Mono<Void>	write(Publisher<? extends T> inputStream, ResolvableType actualType, ResolvableType elementType, MediaType mediaType, ServerHttpRequest request, ServerHttpResponse response, Map<String,Object> hints) Server-side only alternative to HttpMessageWriter.write(Publisher, ResolvableType, MediaType, ReactiveHttpOutputMessage, Map) with additional context available.

Methods inherited from class java.lang.Object

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

Constructor Detail

EncoderHttpMessageWriter

public EncoderHttpMessageWriter(Encoder<T> encoder)

Create an instance wrapping the given Encoder.

Method Detail

getEncoder

public Encoder<T> getEncoder()

Return the Encoder of this writer.

getWritableMediaTypes

public List<MediaType> getWritableMediaTypes()

Description copied from interface: HttpMessageWriter

Return the list of media types supported by this Writer. The list may not apply to every possible target element type and calls to this method should typically be guarded via canWrite(elementType, null). The list may also exclude media types supported only for a specific element type. Alternatively, use HttpMessageWriter.getWritableMediaTypes(ResolvableType) for a more precise list.

Specified by:

getWritableMediaTypes in interface HttpMessageWriter<T>

Returns:

the general list of supported media types

getWritableMediaTypes

public List<MediaType> getWritableMediaTypes(ResolvableType elementType)

Description copied from interface: HttpMessageWriter

Return the list of media types supported by this Writer for the given type of element. This list may differ from HttpMessageWriter.getWritableMediaTypes() if the Writer doesn't support the element type, or if it supports it only for a subset of media types.

Specified by:

getWritableMediaTypes in interface HttpMessageWriter<T>

Parameters:

elementType - the type of element to encode

Returns:

the list of media types supported for the given class

canWrite

public boolean canWrite(ResolvableType elementType,
                        @Nullable
                        MediaType mediaType)

Description copied from interface: HttpMessageWriter

Whether the given object type is supported by this writer.

Specified by:

canWrite in interface HttpMessageWriter<T>

Parameters:

elementType - the type of object to check

mediaType - the media type for the write (possibly null)

Returns:

true if writable, false otherwise

write

public reactor.core.publisher.Mono<Void> write(Publisher<? extends T> inputStream,
                                               ResolvableType elementType,
                                               @Nullable
                                               MediaType mediaType,
                                               ReactiveHttpOutputMessage message,
                                               Map<String,Object> hints)

Description copied from interface: HttpMessageWriter

Write a given stream of object to the output message.

Specified by:

write in interface HttpMessageWriter<T>

Parameters:

inputStream - the objects to write

elementType - the type of objects in the stream which must have been previously checked via HttpMessageWriter.canWrite(ResolvableType, MediaType)

mediaType - the content type for the write (possibly null to indicate that the default content type of the writer must be used)

message - the message to write to

hints - additional information about how to encode and write

Returns:

indicates completion or error

write

public reactor.core.publisher.Mono<Void> write(Publisher<? extends T> inputStream,
                                               ResolvableType actualType,
                                               ResolvableType elementType,
                                               @Nullable
                                               MediaType mediaType,
                                               ServerHttpRequest request,
                                               ServerHttpResponse response,
                                               Map<String,Object> hints)

Description copied from interface: HttpMessageWriter

Server-side only alternative to HttpMessageWriter.write(Publisher, ResolvableType, MediaType, ReactiveHttpOutputMessage, Map) with additional context available.

Specified by:

write in interface HttpMessageWriter<T>

actualType - the actual return type of the method that returned the value; for annotated controllers, the MethodParameter can be accessed via ResolvableType.getSource().

elementType - the type of Objects in the input stream

mediaType - the content type to use (possibly null indicating the default content type of the writer should be used)

request - the current request

response - the current response

Returns:

a Mono that indicates completion of writing or error

getWriteHints

protected Map<String,Object> getWriteHints(ResolvableType streamType,
                                           ResolvableType elementType,
                                           @Nullable
                                           MediaType mediaType,
                                           ServerHttpRequest request,
                                           ServerHttpResponse response)

Get additional hints for encoding for example based on the server request or annotations from controller method parameters. By default, delegate to the encoder if it is an instance of HttpMessageEncoder.