org.springframework.http.codec

Class EncoderHttpMessageWriter<T>

java.lang.Object

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

All Implemented Interfaces:

HttpMessageWriter<T>

public class EncoderHttpMessageWriter<T>
extends java.lang.Object
implements HttpMessageWriter<T>

HttpMessageWriter that wraps and delegates to a 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

Field Summary

Fields

Modifier and Type	Field and Description
private MediaType	defaultMediaType
private Encoder<T>	encoder
private java.util.List<MediaType>	mediaTypes

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
private static MediaType	addDefaultCharset(MediaType main, MediaType defaultType)
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.
java.util.List<MediaType>	getWritableMediaTypes() Return the MediaType's that this writer supports.
protected java.util.Map<java.lang.String,java.lang.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.
private static MediaType	initDefaultMediaType(java.util.List<MediaType> mediaTypes)
private boolean	isStreamingMediaType(MediaType contentType)
private MediaType	updateContentType(ReactiveHttpOutputMessage message, MediaType mediaType)
private static boolean	useFallback(MediaType main, MediaType fallback)
<any>	write(<any> inputStream, ResolvableType elementType, MediaType mediaType, ReactiveHttpOutputMessage message, java.util.Map<java.lang.String,java.lang.Object> hints) Write an given stream of object to the output message.
<any>	write(<any> inputStream, ResolvableType actualType, ResolvableType elementType, MediaType mediaType, ServerHttpRequest request, ServerHttpResponse response, java.util.Map<java.lang.String,java.lang.Object> hints) Server-side only alternative to #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

Field Detail

encoder

private final Encoder<T> encoder

mediaTypes

private final java.util.List<MediaType> mediaTypes

defaultMediaType

@Nullable
private final MediaType defaultMediaType

Constructor Detail

EncoderHttpMessageWriter

public EncoderHttpMessageWriter(Encoder<T> encoder)

Create an instance wrapping the given Encoder.

Method Detail

initDefaultMediaType

@Nullable
private static MediaType initDefaultMediaType(java.util.List<MediaType> mediaTypes)

getEncoder

public Encoder<T> getEncoder()

Return the Encoder of this writer.

getWritableMediaTypes

public java.util.List<MediaType> getWritableMediaTypes()

Description copied from interface: HttpMessageWriter

Return the MediaType's that this writer supports.

Specified by:

getWritableMediaTypes in interface HttpMessageWriter<T>

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 <any> write(<any> inputStream,
                   ResolvableType elementType,
                   @Nullable
                   MediaType mediaType,
                   ReactiveHttpOutputMessage message,
                   java.util.Map<java.lang.String,java.lang.Object> hints)

Description copied from interface: HttpMessageWriter

Write an 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

updateContentType

@Nullable
private MediaType updateContentType(ReactiveHttpOutputMessage message,
                                              @Nullable
                                              MediaType mediaType)

useFallback

private static boolean useFallback(@Nullable
                                   MediaType main,
                                   @Nullable
                                   MediaType fallback)

addDefaultCharset

private static MediaType addDefaultCharset(MediaType main,
                                           @Nullable
                                           MediaType defaultType)

isStreamingMediaType

private boolean isStreamingMediaType(@Nullable
                                     MediaType contentType)

write

public <any> write(<any> inputStream,
                   ResolvableType actualType,
                   ResolvableType elementType,
                   @Nullable
                   MediaType mediaType,
                   ServerHttpRequest request,
                   ServerHttpResponse response,
                   java.util.Map<java.lang.String,java.lang.Object> hints)

Description copied from interface: HttpMessageWriter

Server-side only alternative to #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 java.util.Map<java.lang.String,java.lang.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.