Package org.springframework.http.codec.multipart

Class MultipartHttpMessageWriter

java.lang.Object
org.springframework.http.codec.LoggingCodecSupport
org.springframework.http.codec.multipart.MultipartWriterSupport
org.springframework.http.codec.multipart.MultipartHttpMessageWriter
All Implemented Interfaces:
HttpMessageWriter<org.springframework.util.MultiValueMap<String,?>>
public class MultipartHttpMessageWriter extends MultipartWriterSupport implements HttpMessageWriter<org.springframework.util.MultiValueMap<String,?>>
HttpMessageWriter for writing a MultiValueMap<String, ?> as multipart form data, i.e. "multipart/form-data", to the body of a request.

The serialization of individual parts is delegated to other writers. By default only String and Resource parts are supported but you can configure others through a constructor argument.

This writer can be configured with a FormHttpMessageWriter to delegate to. It is the preferred way of supporting both form data and multipart data (as opposed to registering each writer separately) so that when the MediaType is not specified and generics are not present on the target element type, we can inspect the values in the actual map and decide whether to write plain form data (String values only) or otherwise.

Since:
5.0
Author:
Sebastien Deleuze, Rossen Stoyanchev
See Also:

  • Constructor Details

    • MultipartHttpMessageWriter

      public MultipartHttpMessageWriter()
      Constructor with a default list of part writers (String and Resource).

    • MultipartHttpMessageWriter

      public MultipartHttpMessageWriter(List<HttpMessageWriter<?>> partWriters)
      Constructor with explicit list of writers for serializing parts.

    • MultipartHttpMessageWriter

      public MultipartHttpMessageWriter(List<HttpMessageWriter<?>> partWriters, @Nullable HttpMessageWriter<org.springframework.util.MultiValueMap<String,String>> formWriter)
      Constructor with explicit list of writers for serializing parts and a writer for plain form data to fall back when no media type is specified and the actual map consists of String values only.
      Parameters:
      partWriters - the writers for serializing parts
      formWriter - the fallback writer for form data, null by default

    • MultipartHttpMessageWriter

      public MultipartHttpMessageWriter(Supplier<List<HttpMessageWriter<?>>> partWritersSupplier, @Nullable HttpMessageWriter<org.springframework.util.MultiValueMap<String,String>> formWriter)
      Constructor with a supplier for an explicit list of writers for serializing parts and a writer for plain form data to fall back when no media type is specified and the actual map consists of String values only.
      Parameters:
      partWritersSupplier - the supplier for writers for serializing parts
      formWriter - the fallback writer for form data, null by default
      Since:
      6.0.3

  • Method Details

    • getPartWriters

      public List<HttpMessageWriter<?>> getPartWriters()
      Return the configured part writers.
      Since:
      5.0.7

    • getFormWriter

      @Nullable public HttpMessageWriter<org.springframework.util.MultiValueMap<String,String>> getFormWriter()
      Return the configured form writer.
      Since:
      5.1.13

    • canWrite

      public boolean canWrite(org.springframework.core.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<org.springframework.util.MultiValueMap<String,?>>
      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 org.springframework.util.MultiValueMap<String,?>> inputStream, org.springframework.core.ResolvableType elementType, @Nullable MediaType mediaType, ReactiveHttpOutputMessage outputMessage, 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<org.springframework.util.MultiValueMap<String,?>>
      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)
      outputMessage - the message to write to
      hints - additional information about how to encode and write
      Returns:
      indicates completion or error