org.springframework.http.converter

Interface HttpMessageConverter<T>

Type Parameters:

T - the converted object type

All Known Subinterfaces:

GenericHttpMessageConverter<T>

All Known Implementing Classes:

AbstractGenericHttpMessageConverter, AbstractHttpMessageConverter, AbstractJackson2HttpMessageConverter, AbstractJaxb2HttpMessageConverter, AbstractJsonHttpMessageConverter, AbstractWireFeedHttpMessageConverter, AbstractXmlHttpMessageConverter, AllEncompassingFormHttpMessageConverter, AtomFeedHttpMessageConverter, BufferedImageHttpMessageConverter, ByteArrayHttpMessageConverter, FormHttpMessageConverter, GsonHttpMessageConverter, Jaxb2CollectionHttpMessageConverter, Jaxb2RootElementHttpMessageConverter, JsonbHttpMessageConverter, KotlinSerializationJsonHttpMessageConverter, MappingJackson2CborHttpMessageConverter, MappingJackson2HttpMessageConverter, MappingJackson2SmileHttpMessageConverter, MappingJackson2XmlHttpMessageConverter, MarshallingHttpMessageConverter, ObjectToStringHttpMessageConverter, ProtobufHttpMessageConverter, ProtobufJsonFormatHttpMessageConverter, ResourceHttpMessageConverter, ResourceRegionHttpMessageConverter, RssChannelHttpMessageConverter, SourceHttpMessageConverter, StringHttpMessageConverter

public interface HttpMessageConverter<T>

Strategy interface for converting from and to HTTP requests and responses.

Since:

3.0

Author:

Arjen Poutsma, Juergen Hoeller, Rossen Stoyanchev

Method Summary

Modifier and Type	Method and Description
boolean	canRead(Class<?> clazz, MediaType mediaType) Indicates whether the given class can be read by this converter.
boolean	canWrite(Class<?> clazz, MediaType mediaType) Indicates whether the given class can be written by this converter.
List<MediaType>	getSupportedMediaTypes() Return the list of media types supported by this converter.
default List<MediaType>	getSupportedMediaTypes(Class<?> clazz) Return the list of media types supported by this converter for the given class.
T	read(Class<? extends T> clazz, HttpInputMessage inputMessage) Read an object of the given type from the given input message, and returns it.
void	write(T t, MediaType contentType, HttpOutputMessage outputMessage) Write a given object to the given output message.

Method Detail

canRead

boolean canRead(Class<?> clazz,
                @Nullable
                MediaType mediaType)

Indicates whether the given class can be read by this converter.

Parameters:

clazz - the class to test for readability

mediaType - the media type to read (can be null if not specified); typically the value of a Content-Type header.

Returns:

true if readable; false otherwise

canWrite

boolean canWrite(Class<?> clazz,
                 @Nullable
                 MediaType mediaType)

Indicates whether the given class can be written by this converter.

Parameters:

clazz - the class to test for writability

mediaType - the media type to write (can be null if not specified); typically the value of an Accept header.

Returns:

true if writable; false otherwise

getSupportedMediaTypes

List<MediaType> getSupportedMediaTypes()

Return the list of media types supported by this converter. The list may not apply to every possible target element type and calls to this method should typically be guarded via canWrite(clazz, null. The list may also exclude MIME types supported only for a specific class. Alternatively, use getSupportedMediaTypes(Class) for a more precise list.

Returns:

the list of supported media types

getSupportedMediaTypes

default List<MediaType> getSupportedMediaTypes(Class<?> clazz)

Return the list of media types supported by this converter for the given class. The list may differ from getSupportedMediaTypes() if the converter does not support the given Class or if it supports it only for a subset of media types.

Parameters:

clazz - the type of class to check

Returns:

the list of media types supported for the given class

Since:

5.3.4

read

T read(Class<? extends T> clazz,
       HttpInputMessage inputMessage)
throws IOException,
       HttpMessageNotReadableException

Read an object of the given type from the given input message, and returns it.

Parameters:

clazz - the type of object to return. This type must have previously been passed to the canRead method of this interface, which must have returned true.

inputMessage - the HTTP input message to read from

Returns:

the converted object

Throws:

IOException - in case of I/O errors

HttpMessageNotReadableException - in case of conversion errors

write

void write(T t,
           @Nullable
           MediaType contentType,
           HttpOutputMessage outputMessage)
    throws IOException,
           HttpMessageNotWritableException

Write a given object to the given output message.

Parameters:

t - the object to write to the output message. The type of this object must have previously been passed to the canWrite method of this interface, which must have returned true.

contentType - the content type to use when writing. May be null to indicate that the default content type of the converter must be used. If not null, this media type must have previously been passed to the canWrite method of this interface, which must have returned true.

outputMessage - the message to write to

Throws:

IOException - in case of I/O errors

HttpMessageNotWritableException - in case of conversion errors