org.springframework.http.codec

Class ResourceHttpMessageWriter

java.lang.Object

org.springframework.http.codec.ResourceHttpMessageWriter

All Implemented Interfaces:

HttpMessageWriter<Resource>

public class ResourceHttpMessageWriter
extends java.lang.Object
implements HttpMessageWriter<Resource>

HttpMessageWriter that can write a Resource.

Also an implementation of HttpMessageWriter with support for writing one or more ResourceRegion's based on the HTTP ranges specified in the request.

For reading to a Resource, use ResourceDecoder wrapped with DecoderHttpMessageReader.

Since:

5.0

Author:

Arjen Poutsma, Brian Clozel, Rossen Stoyanchev

See Also:

ResourceEncoder, ResourceRegionEncoder, HttpRange

Field Summary

Fields

Modifier and Type	Field and Description
private ResourceEncoder	encoder
private java.util.List<MediaType>	mediaTypes
private static ResolvableType	REGION_TYPE
private ResourceRegionEncoder	regionEncoder

Constructor Summary

Constructors

Constructor and Description
ResourceHttpMessageWriter()
ResourceHttpMessageWriter(int bufferSize)

Method Summary

Modifier and Type	Method and Description
boolean	canWrite(ResolvableType elementType, MediaType mediaType) Whether the given object type is supported by this writer.
private <any>	encodeAndWriteRegions(<any> publisher, MediaType mediaType, ReactiveHttpOutputMessage message, java.util.Map<java.lang.String,java.lang.Object> hints)
private static MediaType	getResourceMediaType(MediaType mediaType, Resource resource)
java.util.List<MediaType>	getWritableMediaTypes() Return the MediaType's that this writer supports.
private static long	lengthOf(Resource resource)
<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.
private <any>	writeResource(Resource resource, ResolvableType type, MediaType mediaType, ReactiveHttpOutputMessage message, java.util.Map<java.lang.String,java.lang.Object> hints)
private <any>	writeSingleRegion(ResourceRegion region, ReactiveHttpOutputMessage message)
private static java.util.Optional<<any>>	zeroCopy(Resource resource, ResourceRegion region, ReactiveHttpOutputMessage message)

Methods inherited from class java.lang.Object

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

Field Detail

REGION_TYPE

private static final ResolvableType REGION_TYPE

encoder

private final ResourceEncoder encoder

regionEncoder

private final ResourceRegionEncoder regionEncoder

mediaTypes

private final java.util.List<MediaType> mediaTypes

Constructor Detail

ResourceHttpMessageWriter

public ResourceHttpMessageWriter()

ResourceHttpMessageWriter

public ResourceHttpMessageWriter(int bufferSize)

Method Detail

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<Resource>

Parameters:

elementType - the type of object to check

mediaType - the media type for the write, possibly null

Returns:

true if writable, false otherwise

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<Resource>

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<Resource>

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

writeResource

private <any> writeResource(Resource resource,
                            ResolvableType type,
                            @Nullable
                            MediaType mediaType,
                            ReactiveHttpOutputMessage message,
                            java.util.Map<java.lang.String,java.lang.Object> hints)

getResourceMediaType

private static MediaType getResourceMediaType(@Nullable
                                              MediaType mediaType,
                                              Resource resource)

lengthOf

private static long lengthOf(Resource resource)

zeroCopy

private static java.util.Optional<<any>> zeroCopy(Resource resource,
                                                  @Nullable
                                                  ResourceRegion region,
                                                  ReactiveHttpOutputMessage message)

write

public <any> write(<any> inputStream,
                   @Nullable
                   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<Resource>

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

writeSingleRegion

private <any> writeSingleRegion(ResourceRegion region,
                                ReactiveHttpOutputMessage message)

encodeAndWriteRegions

private <any> encodeAndWriteRegions(<any> publisher,
                                    @Nullable
                                    MediaType mediaType,
                                    ReactiveHttpOutputMessage message,
                                    java.util.Map<java.lang.String,java.lang.Object> hints)