org.springframework.http.converter

Class BufferedImageHttpMessageConverter

java.lang.Object

org.springframework.http.converter.BufferedImageHttpMessageConverter

All Implemented Interfaces:

HttpMessageConverter<java.awt.image.BufferedImage>

public class BufferedImageHttpMessageConverter
extends java.lang.Object
implements HttpMessageConverter<java.awt.image.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

Field Summary

Fields

Modifier and Type	Field and Description
private java.io.File	cacheDir
private MediaType	defaultContentType
private java.util.List<MediaType>	readableMediaTypes

Constructor Summary

Constructors

Constructor and Description
BufferedImageHttpMessageConverter()

Method Summary

Modifier and Type	Method and Description
boolean	canRead(java.lang.Class<?> clazz, MediaType mediaType) Indicates whether the given class can be read by this converter.
boolean	canWrite(java.lang.Class<?> clazz, MediaType mediaType) Indicates whether the given class can be written by this converter.
private javax.imageio.stream.ImageInputStream	createImageInputStream(java.io.InputStream is)
private javax.imageio.stream.ImageOutputStream	createImageOutputStream(java.io.OutputStream os)
MediaType	getDefaultContentType() Returns the default Content-Type to be used for writing.
java.util.List<MediaType>	getSupportedMediaTypes() Return the list of MediaType objects supported by this converter.
private boolean	isReadable(MediaType mediaType)
private boolean	isWritable(MediaType mediaType)
protected void	process(javax.imageio.ImageReadParam irp) Template method that allows for manipulating the ImageReadParam before it is used to read an image.
protected void	process(javax.imageio.ImageWriteParam iwp) Template method that allows for manipulating the ImageWriteParam before it is used to write an image.
java.awt.image.BufferedImage	read(java.lang.Class<? extends java.awt.image.BufferedImage> clazz, HttpInputMessage inputMessage) Read an object of the given type form the given input message, and returns it.
void	setCacheDir(java.io.File cacheDir) Sets the cache directory.
void	setDefaultContentType(MediaType defaultContentType) Sets the default Content-Type to be used for writing.
void	write(java.awt.image.BufferedImage image, MediaType contentType, HttpOutputMessage outputMessage) Write an 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

Field Detail

readableMediaTypes

private final java.util.List<MediaType> readableMediaTypes

defaultContentType

private MediaType defaultContentType

cacheDir

private java.io.File cacheDir

Constructor Detail

BufferedImageHttpMessageConverter

public BufferedImageHttpMessageConverter()

Method Detail

setDefaultContentType

public void setDefaultContentType(MediaType defaultContentType)

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

Throws:

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

getDefaultContentType

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(java.io.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(java.lang.Class<?> clazz,
                       MediaType mediaType)

Description copied from interface: HttpMessageConverter

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

Specified by:

canRead in interface HttpMessageConverter<java.awt.image.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

isReadable

private boolean isReadable(MediaType mediaType)

canWrite

public boolean canWrite(java.lang.Class<?> clazz,
                        MediaType mediaType)

Description copied from interface: HttpMessageConverter

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

Specified by:

canWrite in interface HttpMessageConverter<java.awt.image.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

isWritable

private boolean isWritable(MediaType mediaType)

getSupportedMediaTypes

public java.util.List<MediaType> getSupportedMediaTypes()

Description copied from interface: HttpMessageConverter

Return the list of MediaType objects supported by this converter.

Specified by:

getSupportedMediaTypes in interface HttpMessageConverter<java.awt.image.BufferedImage>

Returns:

the list of supported media types

read

public java.awt.image.BufferedImage read(java.lang.Class<? extends java.awt.image.BufferedImage> clazz,
                                         HttpInputMessage inputMessage)
                                  throws java.io.IOException,
                                         HttpMessageNotReadableException

Description copied from interface: HttpMessageConverter

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

Specified by:

read in interface HttpMessageConverter<java.awt.image.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:

java.io.IOException - in case of I/O errors

HttpMessageNotReadableException - in case of conversion errors

createImageInputStream

private javax.imageio.stream.ImageInputStream createImageInputStream(java.io.InputStream is)
                                                              throws java.io.IOException

Throws:

java.io.IOException

write

public void write(java.awt.image.BufferedImage image,
                  MediaType contentType,
                  HttpOutputMessage outputMessage)
           throws java.io.IOException,
                  HttpMessageNotWritableException

Description copied from interface: HttpMessageConverter

Write an given object to the given output message.

Specified by:

write in interface HttpMessageConverter<java.awt.image.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:

java.io.IOException - in case of I/O errors

HttpMessageNotWritableException - in case of conversion errors

createImageOutputStream

private javax.imageio.stream.ImageOutputStream createImageOutputStream(java.io.OutputStream os)
                                                                throws java.io.IOException

Throws:

java.io.IOException

process

protected void process(javax.imageio.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(javax.imageio.ImageWriteParam iwp)

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

The default implementation is empty.