Class AbstractGenericHttpMessageConverter<T>

java.lang.Object

org.springframework.http.converter.AbstractHttpMessageConverter<T>

org.springframework.http.converter.AbstractGenericHttpMessageConverter<T>

Type Parameters:

T - the converted object type

All Implemented Interfaces:

GenericHttpMessageConverter<T>, HttpMessageConverter<T>

Direct Known Subclasses:

AbstractJackson2HttpMessageConverter, AbstractJsonHttpMessageConverter, ResourceRegionHttpMessageConverter

public abstract class AbstractGenericHttpMessageConverter<T>
extends AbstractHttpMessageConverter<T>
implements GenericHttpMessageConverter<T>

Abstract base class for most GenericHttpMessageConverter implementations.

Since:

4.2

Author:

Sebastien Deleuze, Juergen Hoeller

Field Summary

Fields inherited from class AbstractHttpMessageConverter

logger

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractGenericHttpMessageConverter()	Construct an AbstractGenericHttpMessageConverter with no supported media types.
protected	AbstractGenericHttpMessageConverter(Charset defaultCharset, MediaType... supportedMediaTypes)	Construct an AbstractGenericHttpMessageConverter with a default charset and multiple supported media types.
protected	AbstractGenericHttpMessageConverter(MediaType supportedMediaType)	Construct an AbstractGenericHttpMessageConverter with one supported media type.
protected	AbstractGenericHttpMessageConverter(MediaType... supportedMediaTypes)	Construct an AbstractGenericHttpMessageConverter with multiple supported media type.

Method Summary

Modifier and Type	Method	Description
boolean	canRead(Type type, @Nullable Class<?> contextClass, @Nullable MediaType mediaType)	Indicates whether the given type can be read by this converter.
boolean	canWrite(@Nullable Type type, Class<?> clazz, @Nullable MediaType mediaType)	Indicates whether the given class can be written by this converter.
protected boolean	supports(Class<?> clazz)	Indicates whether the given class is supported by this converter.
final void	write(T t, @Nullable Type type, @Nullable MediaType contentType, HttpOutputMessage outputMessage)	This implementation sets the default headers by calling AbstractHttpMessageConverter.addDefaultHeaders(HttpHeaders, T, MediaType), and then calls writeInternal(T, HttpOutputMessage).
protected abstract void	writeInternal(T t, @Nullable Type type, HttpOutputMessage outputMessage)	Abstract template method that writes the actual body.
protected void	writeInternal(T t, HttpOutputMessage outputMessage)	Abstract template method that writes the actual body.

Methods inherited from class AbstractHttpMessageConverter

addDefaultHeaders, canRead, canRead, canWrite, canWrite, getContentLength, getDefaultCharset, getDefaultContentType, getSupportedMediaTypes, read, readInternal, setDefaultCharset, setSupportedMediaTypes, supportsRepeatableWrites, write

Methods inherited from class Object

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

Methods inherited from interface GenericHttpMessageConverter

read

Methods inherited from interface HttpMessageConverter

canRead, canWrite, getSupportedMediaTypes, getSupportedMediaTypes, read, write

Constructor Details

AbstractGenericHttpMessageConverter

protected AbstractGenericHttpMessageConverter()

Construct an AbstractGenericHttpMessageConverter with no supported media types.

See Also:

• AbstractHttpMessageConverter.setSupportedMediaTypes(List)

AbstractGenericHttpMessageConverter

protected AbstractGenericHttpMessageConverter(MediaType supportedMediaType)

Construct an AbstractGenericHttpMessageConverter with one supported media type.

Parameters:

supportedMediaType - the supported media type

AbstractGenericHttpMessageConverter

protected AbstractGenericHttpMessageConverter(MediaType... supportedMediaTypes)

Construct an AbstractGenericHttpMessageConverter with multiple supported media type.

Parameters:

supportedMediaTypes - the supported media types

AbstractGenericHttpMessageConverter

protected AbstractGenericHttpMessageConverter(Charset defaultCharset,
 MediaType... supportedMediaTypes)

Construct an AbstractGenericHttpMessageConverter with a default charset and multiple supported media types.

Parameters:

defaultCharset - the default character set

supportedMediaTypes - the supported media types

Since:

6.2

Method Details

supports

protected boolean supports(Class<?> clazz)

Description copied from class: AbstractHttpMessageConverter

Indicates whether the given class is supported by this converter.

Specified by:

supports in class AbstractHttpMessageConverter<T>

Parameters:

clazz - the class to test for support

Returns:

true if supported; false otherwise

canRead

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

Description copied from interface: GenericHttpMessageConverter

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

Specified by:

canRead in interface GenericHttpMessageConverter<T>

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

canWrite

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

Description copied from interface: GenericHttpMessageConverter

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

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

Specified by:

canWrite in interface GenericHttpMessageConverter<T>

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

write

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

This implementation sets the default headers by calling AbstractHttpMessageConverter.addDefaultHeaders(HttpHeaders, T, MediaType), and then calls writeInternal(T, HttpOutputMessage).

Specified by:

write in interface GenericHttpMessageConverter<T>

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

writeInternal

protected void writeInternal(T t,
 HttpOutputMessage outputMessage)
                      throws IOException,
HttpMessageNotWritableException

Description copied from class: AbstractHttpMessageConverter

Abstract template method that writes the actual body. Invoked from AbstractHttpMessageConverter.write(T, MediaType, HttpOutputMessage).

Specified by:

writeInternal in class AbstractHttpMessageConverter<T>

Parameters:

t - the object to write to the output message

outputMessage - the HTTP output message to write to

Throws:

IOException - in case of I/O errors

HttpMessageNotWritableException - in case of conversion errors

writeInternal

protected abstract void writeInternal(T t,
 @Nullable Type type,
 HttpOutputMessage outputMessage)
                               throws IOException,
HttpMessageNotWritableException

Abstract template method that writes the actual body. Invoked from write(T, Type, MediaType, HttpOutputMessage).

Parameters:

t - the object to write to the output message

type - the type of object to write (may be null)

outputMessage - the HTTP output message to write to

Throws:

IOException - in case of I/O errors

HttpMessageNotWritableException - in case of conversion errors