org.springframework.http.converter

Interface GenericHttpMessageConverter<T>

Type Parameters:

T - the converted object type

All Superinterfaces:

HttpMessageConverter<T>

All Known Implementing Classes:

AbstractGenericHttpMessageConverter, AbstractJackson2HttpMessageConverter, AbstractJsonHttpMessageConverter, GsonHttpMessageConverter, Jaxb2CollectionHttpMessageConverter, JsonbHttpMessageConverter, MappingJackson2CborHttpMessageConverter, MappingJackson2HttpMessageConverter, MappingJackson2SmileHttpMessageConverter, MappingJackson2XmlHttpMessageConverter, ResourceRegionHttpMessageConverter

public interface GenericHttpMessageConverter<T>
extends HttpMessageConverter<T>

A specialization of HttpMessageConverter that can convert an HTTP request into a target object of a specified generic type and a source object of a specified generic type into an HTTP response.

Since:

3.2

Author:

Arjen Poutsma, Rossen Stoyanchev, Sebastien Deleuze

See Also:

ParameterizedTypeReference

Method Summary

Modifier and Type	Method and Description
boolean	canRead(Type type, Class<?> contextClass, MediaType mediaType) Indicates whether the given type can be read by this converter.
boolean	canWrite(Type type, Class<?> clazz, MediaType mediaType) Indicates whether the given class can be written by this converter.
T	read(Type type, Class<?> contextClass, HttpInputMessage inputMessage) Read an object of the given type form the given input message, and returns it.
void	write(T t, Type type, MediaType contentType, HttpOutputMessage outputMessage) Write an given object to the given output message.

Methods inherited from interface org.springframework.http.converter.HttpMessageConverter

canRead, canWrite, getSupportedMediaTypes, read, write

Method Detail

canRead

boolean canRead(Type type,
                @Nullable
                Class<?> contextClass,
                @Nullable
                MediaType mediaType)

Indicates whether the given type can be read by this converter. This method should perform the same checks than HttpMessageConverter.canRead(Class, MediaType) with additional ones related to the generic type.

Parameters:

type - the (potentially generic) type to test for readability

contextClass - a context class for the target type, for example a class in which the target type appears in a method signature (can be null)

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

read

T read(Type type,
       @Nullable
       Class<?> contextClass,
       HttpInputMessage inputMessage)
throws IOException,
       HttpMessageNotReadableException

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

Parameters:

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

contextClass - a context class for the target type, for example a class in which the target type appears in a method signature (can be null)

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

canWrite

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

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

This method should perform the same checks than HttpMessageConverter.canWrite(Class, MediaType) with additional ones related to the generic type.

Parameters:

type - the (potentially generic) type to test for writability (can be null if not specified)

clazz - the source object 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

Since:

4.2

write

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

Write an 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.

type - the (potentially generic) type of object to write. This type must have previously been passed to the canWrite method of this interface, which must have returned true. Can be null if not specified.

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

Since:

4.2