Package org.springframework.http.converter

Class BufferedImageHttpMessageConverter

java.lang.Object

org.springframework.http.converter.BufferedImageHttpMessageConverter

All Implemented Interfaces:

HttpMessageConverter<BufferedImage>

public class BufferedImageHttpMessageConverter
extends Object
implements HttpMessageConverter<BufferedImage>

Implementation of HttpMessageConverter that can read and write BufferedImages.

By default, this converter can read all media types that are supported by the registered image readers, and writes using the media type of the first available registered image writer. The latter can be overridden by setting the defaultContentType property.

If the cacheDir property is set, this converter will cache image data.

The process(ImageReadParam) and process(ImageWriteParam) template methods allow subclasses to override Image I/O parameters.

Since:

3.0

Author:

Arjen Poutsma

Constructor Summary

Constructors

Constructor	Description
BufferedImageHttpMessageConverter()

Method Summary

Modifier and Type	Method	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.
MediaType	getDefaultContentType()	Returns the default Content-Type to be used for writing.
List<MediaType>	getSupportedMediaTypes()	Return the list of media types supported by this converter.
protected void	process(ImageReadParam irp)	Template method that allows for manipulating the ImageReadParam before it is used to read an image.
protected void	process(ImageWriteParam iwp)	Template method that allows for manipulating the ImageWriteParam before it is used to write an image.
BufferedImage	read(Class<? extends BufferedImage> clazz, HttpInputMessage inputMessage)	Read an object of the given type from the given input message, and returns it.
void	setCacheDir(File cacheDir)	Sets the cache directory.
void	setDefaultContentType(MediaType defaultContentType)	Sets the default Content-Type to be used for writing.
void	write(BufferedImage image, MediaType contentType, HttpOutputMessage outputMessage)	Write a given object to the given output message.

Methods inherited from class java.lang.Object

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

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

getSupportedMediaTypes

Constructor Details

BufferedImageHttpMessageConverter

public BufferedImageHttpMessageConverter()

Method Details

setDefaultContentType

public void setDefaultContentType(@Nullable
 MediaType defaultContentType)

Sets the default Content-Type to be used for writing.

Throws:

IllegalArgumentException - if the given content type is not supported by the Java Image I/O API

getDefaultContentType

@Nullable
public MediaType getDefaultContentType()

Returns the default Content-Type to be used for writing. Called when write(java.awt.image.BufferedImage, org.springframework.http.MediaType, org.springframework.http.HttpOutputMessage) is invoked without a specified content type parameter.

setCacheDir

public void setCacheDir(File cacheDir)

Sets the cache directory. If this property is set to an existing directory, this converter will cache image data.

canRead

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

Description copied from interface: HttpMessageConverter

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

Specified by:

canRead in interface HttpMessageConverter<BufferedImage>

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

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

Description copied from interface: HttpMessageConverter

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

Specified by:

canWrite in interface HttpMessageConverter<BufferedImage>

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

public List<MediaType> getSupportedMediaTypes()

Description copied from interface: HttpMessageConverter

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 HttpMessageConverter.getSupportedMediaTypes(Class) for a more precise list.

Specified by:

getSupportedMediaTypes in interface HttpMessageConverter<BufferedImage>

Returns:

the list of supported media types

read

public BufferedImage read(@Nullable
 Class<? extends BufferedImage> clazz,
 HttpInputMessage inputMessage)
                   throws IOException,
HttpMessageNotReadableException

Description copied from interface: HttpMessageConverter

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

Specified by:

read in interface HttpMessageConverter<BufferedImage>

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

public void write(BufferedImage image,
 @Nullable
 MediaType contentType,
 HttpOutputMessage outputMessage)
           throws IOException,
HttpMessageNotWritableException

Description copied from interface: HttpMessageConverter

Write a given object to the given output message.

Specified by:

write in interface HttpMessageConverter<BufferedImage>

Parameters:

image - 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

process

protected void process(ImageReadParam irp)

Template method that allows for manipulating the ImageReadParam before it is used to read an image.

The default implementation is empty.

process

protected void process(ImageWriteParam iwp)

Template method that allows for manipulating the ImageWriteParam before it is used to write an image.

The default implementation is empty.