Class FormHttpMessageWriter

java.lang.Object

org.springframework.http.codec.LoggingCodecSupport

org.springframework.http.codec.FormHttpMessageWriter

All Implemented Interfaces:

HttpMessageWriter<MultiValueMap<String,String>>

public class FormHttpMessageWriter
extends LoggingCodecSupport
implements HttpMessageWriter<MultiValueMap<String,String>>

HttpMessageWriter for writing a MultiValueMap<String, String> as HTML form data, i.e. "application/x-www-form-urlencoded", to the body of a request.

Note that unless the media type is explicitly set to MediaType.APPLICATION_FORM_URLENCODED, the canWrite(ResolvableType, MediaType) method will need generic type information to confirm the target map has String values. This is because a MultiValueMap with non-String values can be used to write multipart requests.

To support both form data and multipart requests, consider using MultipartHttpMessageWriter configured with this writer as the fallback for writing plain form data.

Since:

5.0

Author:

Sebastien Deleuze, Rossen Stoyanchev

See Also:

• MultipartHttpMessageWriter

Field Summary

Fields

Modifier and Type	Field	Description
static final Charset	DEFAULT_CHARSET	The default charset used by the writer.

Fields inherited from class LoggingCodecSupport

logger

Constructor Summary

Constructors

Constructor	Description
FormHttpMessageWriter()

Method Summary

Modifier and Type	Method	Description
boolean	canWrite(ResolvableType elementType, @Nullable MediaType mediaType)	Whether the given object type is supported by this writer.
Charset	getDefaultCharset()	Return the configured default charset.
protected MediaType	getMediaType(@Nullable MediaType mediaType)	Return the content type used to write forms, either the given media type or otherwise application/x-www-form-urlencoded.
List<MediaType>	getWritableMediaTypes()	Return the list of media types supported by this Writer.
protected String	serializeForm(MultiValueMap<String,String> formData, Charset charset)
void	setDefaultCharset(Charset charset)	Set the default character set to use for writing form data when the response Content-Type header does not explicitly specify it.
reactor.core.publisher.Mono<Void>	write(Publisher<? extends MultiValueMap<String,String>> inputStream, ResolvableType elementType, @Nullable MediaType mediaType, ReactiveHttpOutputMessage message, Map<String,Object> hints)	Write a given stream of object to the output message.

Methods inherited from class LoggingCodecSupport

isEnableLoggingRequestDetails, setEnableLoggingRequestDetails

Methods inherited from class Object

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

Methods inherited from interface HttpMessageWriter

getWritableMediaTypes, write

Field Details

DEFAULT_CHARSET

public static final Charset DEFAULT_CHARSET

The default charset used by the writer.

Constructor Details

FormHttpMessageWriter

public FormHttpMessageWriter()

Method Details

setDefaultCharset

public void setDefaultCharset(Charset charset)

Set the default character set to use for writing form data when the response Content-Type header does not explicitly specify it.

By default this is set to "UTF-8".

getDefaultCharset

public Charset getDefaultCharset()

Return the configured default charset.

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<MultiValueMap<String,String>>

Returns:

the general list of supported media types

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<MultiValueMap<String,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 MultiValueMap<String,String>> 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<MultiValueMap<String,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)

message - the message to write to

hints - additional information about how to encode and write

Returns:

indicates completion or error

getMediaType

protected MediaType getMediaType(@Nullable MediaType mediaType)

Return the content type used to write forms, either the given media type or otherwise application/x-www-form-urlencoded.

Parameters:

mediaType - the media type passed to write(Publisher, ResolvableType, MediaType, ReactiveHttpOutputMessage, Map), or null

Returns:

the content type to use

serializeForm

protected String serializeForm(MultiValueMap<String,String> formData,
 Charset charset)