< prev index next >
src/java.desktop/share/classes/javax/imageio/spi/ImageWriterSpi.java
Print this page
*** 30,71 ****
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageOutputStream;
/**
! * The service provider interface (SPI) for <code>ImageWriter</code>s.
* For more information on service provider classes, see the class comment
! * for the <code>IIORegistry</code> class.
*
! * <p> Each <code>ImageWriterSpi</code> provides several types of information
! * about the <code>ImageWriter</code> class with which it is associated.
*
* <p> The name of the vendor who defined the SPI class and a
* brief description of the class are available via the
! * <code>getVendorName</code>, <code>getDescription</code>,
! * and <code>getVersion</code> methods.
* These methods may be internationalized to provide locale-specific
* output. These methods are intended mainly to provide short,
* human-writable information that might be used to organize a pop-up
* menu or other list.
*
* <p> Lists of format names, file suffixes, and MIME types associated
* with the service may be obtained by means of the
! * <code>getFormatNames</code>, <code>getFileSuffixes</code>, and
! * <code>getMIMEType</code> methods. These methods may be used to
! * identify candidate <code>ImageWriter</code>s for writing a
* particular file or stream based on manual format selection, file
* naming, or MIME associations.
*
! * <p> A more reliable way to determine which <code>ImageWriter</code>s
* are likely to be able to parse a particular data stream is provided
! * by the <code>canEncodeImage</code> method. This methods allows the
* service provider to inspect the actual image contents.
*
! * <p> Finally, an instance of the <code>ImageWriter</code> class
* associated with this service provider may be obtained by calling
! * the <code>createWriterInstance</code> method. Any heavyweight
* initialization, such as the loading of native libraries or creation
* of large tables, should be deferred at least until the first
* invocation of this method.
*
* @see IIORegistry
--- 30,71 ----
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageOutputStream;
/**
! * The service provider interface (SPI) for {@code ImageWriter}s.
* For more information on service provider classes, see the class comment
! * for the {@code IIORegistry} class.
*
! * <p> Each {@code ImageWriterSpi} provides several types of information
! * about the {@code ImageWriter} class with which it is associated.
*
* <p> The name of the vendor who defined the SPI class and a
* brief description of the class are available via the
! * {@code getVendorName}, {@code getDescription},
! * and {@code getVersion} methods.
* These methods may be internationalized to provide locale-specific
* output. These methods are intended mainly to provide short,
* human-writable information that might be used to organize a pop-up
* menu or other list.
*
* <p> Lists of format names, file suffixes, and MIME types associated
* with the service may be obtained by means of the
! * {@code getFormatNames}, {@code getFileSuffixes}, and
! * {@code getMIMEType} methods. These methods may be used to
! * identify candidate {@code ImageWriter}s for writing a
* particular file or stream based on manual format selection, file
* naming, or MIME associations.
*
! * <p> A more reliable way to determine which {@code ImageWriter}s
* are likely to be able to parse a particular data stream is provided
! * by the {@code canEncodeImage} method. This methods allows the
* service provider to inspect the actual image contents.
*
! * <p> Finally, an instance of the {@code ImageWriter} class
* associated with this service provider may be obtained by calling
! * the {@code createWriterInstance} method. Any heavyweight
* initialization, such as the loading of native libraries or creation
* of large tables, should be deferred at least until the first
* invocation of this method.
*
* @see IIORegistry
*** 75,198 ****
*/
public abstract class ImageWriterSpi extends ImageReaderWriterSpi {
/**
* A single-element array, initially containing
! * <code>ImageOutputStream.class</code>, to be returned from
! * <code>getOutputTypes</code>.
* @deprecated Instead of using this field, directly create
! * the equivalent array <code>{ ImageOutputStream.class }</code>.
*/
@Deprecated
public static final Class<?>[] STANDARD_OUTPUT_TYPE =
{ ImageOutputStream.class };
/**
! * An array of <code>Class</code> objects to be returned from
! * <code>getOutputTypes</code>, initially <code>null</code>.
*/
protected Class<?>[] outputTypes = null;
/**
* An array of strings to be returned from
! * <code>getImageReaderSpiNames</code>, initially
! * <code>null</code>.
*/
protected String[] readerSpiNames = null;
/**
! * The <code>Class</code> of the writer, initially
! * <code>null</code>.
*/
private Class<?> writerClass = null;
/**
! * Constructs a blank <code>ImageWriterSpi</code>. It is up to
* the subclass to initialize instance variables and/or override
* method implementations in order to provide working versions of
* all methods.
*/
protected ImageWriterSpi() {
}
/**
! * Constructs an <code>ImageWriterSpi</code> with a given
* set of values.
*
! * @param vendorName the vendor name, as a non-<code>null</code>
! * <code>String</code>.
! * @param version a version identifier, as a non-<code>null</code>
! * <code>String</code>.
! * @param names a non-<code>null</code> array of
! * <code>String</code>s indicating the format names. At least one
* entry must be present.
! * @param suffixes an array of <code>String</code>s indicating the
* common file suffixes. If no suffixes are defined,
! * <code>null</code> should be supplied. An array of length 0
! * will be normalized to <code>null</code>.
! * @param MIMETypes an array of <code>String</code>s indicating
* the format's MIME types. If no suffixes are defined,
! * <code>null</code> should be supplied. An array of length 0
! * will be normalized to <code>null</code>.
* @param writerClassName the fully-qualified name of the
! * associated <code>ImageWriterSpi</code> class, as a
! * non-<code>null</code> <code>String</code>.
! * @param outputTypes an array of <code>Class</code> objects of
* length at least 1 indicating the legal output types.
! * @param readerSpiNames an array <code>String</code>s of length
* at least 1 naming the classes of all associated
! * <code>ImageReader</code>s, or <code>null</code>. An array of
! * length 0 is normalized to <code>null</code>.
* @param supportsStandardStreamMetadataFormat a
! * <code>boolean</code> that indicates whether a stream metadata
* object can use trees described by the standard metadata format.
* @param nativeStreamMetadataFormatName a
! * <code>String</code>, or <code>null</code>, to be returned from
! * <code>getNativeStreamMetadataFormatName</code>.
* @param nativeStreamMetadataFormatClassName a
! * <code>String</code>, or <code>null</code>, to be used to instantiate
* a metadata format object to be returned from
! * <code>getNativeStreamMetadataFormat</code>.
* @param extraStreamMetadataFormatNames an array of
! * <code>String</code>s, or <code>null</code>, to be returned from
! * <code>getExtraStreamMetadataFormatNames</code>. An array of length
! * 0 is normalized to <code>null</code>.
* @param extraStreamMetadataFormatClassNames an array of
! * <code>String</code>s, or <code>null</code>, to be used to instantiate
* a metadata format object to be returned from
! * <code>getStreamMetadataFormat</code>. An array of length
! * 0 is normalized to <code>null</code>.
* @param supportsStandardImageMetadataFormat a
! * <code>boolean</code> that indicates whether an image metadata
* object can use trees described by the standard metadata format.
* @param nativeImageMetadataFormatName a
! * <code>String</code>, or <code>null</code>, to be returned from
! * <code>getNativeImageMetadataFormatName</code>.
* @param nativeImageMetadataFormatClassName a
! * <code>String</code>, or <code>null</code>, to be used to instantiate
* a metadata format object to be returned from
! * <code>getNativeImageMetadataFormat</code>.
* @param extraImageMetadataFormatNames an array of
! * <code>String</code>s to be returned from
! * <code>getExtraImageMetadataFormatNames</code>. An array of length 0
! * is normalized to <code>null</code>.
* @param extraImageMetadataFormatClassNames an array of
! * <code>String</code>s, or <code>null</code>, to be used to instantiate
* a metadata format object to be returned from
! * <code>getImageMetadataFormat</code>. An array of length
! * 0 is normalized to <code>null</code>.
*
! * @exception IllegalArgumentException if <code>vendorName</code>
! * is <code>null</code>.
! * @exception IllegalArgumentException if <code>version</code>
! * is <code>null</code>.
! * @exception IllegalArgumentException if <code>names</code>
! * is <code>null</code> or has length 0.
! * @exception IllegalArgumentException if <code>writerClassName</code>
! * is <code>null</code>.
! * @exception IllegalArgumentException if <code>outputTypes</code>
! * is <code>null</code> or has length 0.
*/
public ImageWriterSpi(String vendorName,
String version,
String[] names,
String[] suffixes,
--- 75,198 ----
*/
public abstract class ImageWriterSpi extends ImageReaderWriterSpi {
/**
* A single-element array, initially containing
! * {@code ImageOutputStream.class}, to be returned from
! * {@code getOutputTypes}.
* @deprecated Instead of using this field, directly create
! * the equivalent array {@code { ImageOutputStream.class }}.
*/
@Deprecated
public static final Class<?>[] STANDARD_OUTPUT_TYPE =
{ ImageOutputStream.class };
/**
! * An array of {@code Class} objects to be returned from
! * {@code getOutputTypes}, initially {@code null}.
*/
protected Class<?>[] outputTypes = null;
/**
* An array of strings to be returned from
! * {@code getImageReaderSpiNames}, initially
! * {@code null}.
*/
protected String[] readerSpiNames = null;
/**
! * The {@code Class} of the writer, initially
! * {@code null}.
*/
private Class<?> writerClass = null;
/**
! * Constructs a blank {@code ImageWriterSpi}. It is up to
* the subclass to initialize instance variables and/or override
* method implementations in order to provide working versions of
* all methods.
*/
protected ImageWriterSpi() {
}
/**
! * Constructs an {@code ImageWriterSpi} with a given
* set of values.
*
! * @param vendorName the vendor name, as a non-{@code null}
! * {@code String}.
! * @param version a version identifier, as a non-{@code null}
! * {@code String}.
! * @param names a non-{@code null} array of
! * {@code String}s indicating the format names. At least one
* entry must be present.
! * @param suffixes an array of {@code String}s indicating the
* common file suffixes. If no suffixes are defined,
! * {@code null} should be supplied. An array of length 0
! * will be normalized to {@code null}.
! * @param MIMETypes an array of {@code String}s indicating
* the format's MIME types. If no suffixes are defined,
! * {@code null} should be supplied. An array of length 0
! * will be normalized to {@code null}.
* @param writerClassName the fully-qualified name of the
! * associated {@code ImageWriterSpi} class, as a
! * non-{@code null String}.
! * @param outputTypes an array of {@code Class} objects of
* length at least 1 indicating the legal output types.
! * @param readerSpiNames an array {@code String}s of length
* at least 1 naming the classes of all associated
! * {@code ImageReader}s, or {@code null}. An array of
! * length 0 is normalized to {@code null}.
* @param supportsStandardStreamMetadataFormat a
! * {@code boolean} that indicates whether a stream metadata
* object can use trees described by the standard metadata format.
* @param nativeStreamMetadataFormatName a
! * {@code String}, or {@code null}, to be returned from
! * {@code getNativeStreamMetadataFormatName}.
* @param nativeStreamMetadataFormatClassName a
! * {@code String}, or {@code null}, to be used to instantiate
* a metadata format object to be returned from
! * {@code getNativeStreamMetadataFormat}.
* @param extraStreamMetadataFormatNames an array of
! * {@code String}s, or {@code null}, to be returned from
! * {@code getExtraStreamMetadataFormatNames}. An array of length
! * 0 is normalized to {@code null}.
* @param extraStreamMetadataFormatClassNames an array of
! * {@code String}s, or {@code null}, to be used to instantiate
* a metadata format object to be returned from
! * {@code getStreamMetadataFormat}. An array of length
! * 0 is normalized to {@code null}.
* @param supportsStandardImageMetadataFormat a
! * {@code boolean} that indicates whether an image metadata
* object can use trees described by the standard metadata format.
* @param nativeImageMetadataFormatName a
! * {@code String}, or {@code null}, to be returned from
! * {@code getNativeImageMetadataFormatName}.
* @param nativeImageMetadataFormatClassName a
! * {@code String}, or {@code null}, to be used to instantiate
* a metadata format object to be returned from
! * {@code getNativeImageMetadataFormat}.
* @param extraImageMetadataFormatNames an array of
! * {@code String}s to be returned from
! * {@code getExtraImageMetadataFormatNames}. An array of length 0
! * is normalized to {@code null}.
* @param extraImageMetadataFormatClassNames an array of
! * {@code String}s, or {@code null}, to be used to instantiate
* a metadata format object to be returned from
! * {@code getImageMetadataFormat}. An array of length
! * 0 is normalized to {@code null}.
*
! * @exception IllegalArgumentException if {@code vendorName}
! * is {@code null}.
! * @exception IllegalArgumentException if {@code version}
! * is {@code null}.
! * @exception IllegalArgumentException if {@code names}
! * is {@code null} or has length 0.
! * @exception IllegalArgumentException if {@code writerClassName}
! * is {@code null}.
! * @exception IllegalArgumentException if {@code outputTypes}
! * is {@code null} or has length 0.
*/
public ImageWriterSpi(String vendorName,
String version,
String[] names,
String[] suffixes,
*** 241,436 ****
this.readerSpiNames = readerSpiNames.clone();
}
}
/**
! * Returns <code>true</code> if the format that this writer
* outputs preserves pixel data bit-accurately. The default
! * implementation returns <code>true</code>.
*
! * @return <code>true</code> if the format preserves full pixel
* accuracy.
*/
public boolean isFormatLossless() {
return true;
}
/**
! * Returns an array of <code>Class</code> objects indicating what
* types of objects may be used as arguments to the writer's
! * <code>setOutput</code> method.
*
* <p> For most writers, which only output to an
! * <code>ImageOutputStream</code>, a single-element array
! * containing <code>ImageOutputStream.class</code> should be
* returned.
*
! * @return a non-<code>null</code> array of
! * <code>Class</code> objects of length at least 1.
*/
public Class<?>[] getOutputTypes() {
return outputTypes.clone();
}
/**
! * Returns <code>true</code> if the <code>ImageWriter</code>
* implementation associated with this service provider is able to
* encode an image with the given layout. The layout
! * (<i>i.e.</i>, the image's <code>SampleModel</code> and
! * <code>ColorModel</code>) is described by an
! * <code>ImageTypeSpecifier</code> object.
*
! * <p> A return value of <code>true</code> is not an absolute
* guarantee of successful encoding; the encoding process may still
* produce errors due to factors such as I/O errors, inconsistent
* or malformed data structures, etc. The intent is that a
* reasonable inspection of the basic structure of the image be
* performed in order to determine if it is within the scope of
* the encoding format. For example, a service provider for a
* format that can only encode greyscale would return
! * <code>false</code> if handed an RGB <code>BufferedImage</code>.
* Similarly, a service provider for a format that can encode
* 8-bit RGB imagery might refuse to encode an image with an
* associated alpha channel.
*
! * <p> Different <code>ImageWriter</code>s, and thus service
* providers, may choose to be more or less strict. For example,
* they might accept an image with premultiplied alpha even though
* it will have to be divided out of each pixel, at some loss of
* precision, in order to be stored.
*
! * @param type an <code>ImageTypeSpecifier</code> specifying the
* layout of the image to be written.
*
! * @return <code>true</code> if this writer is likely to be able
* to encode images with the given layout.
*
! * @exception IllegalArgumentException if <code>type</code>
! * is <code>null</code>.
*/
public abstract boolean canEncodeImage(ImageTypeSpecifier type);
/**
! * Returns <code>true</code> if the <code>ImageWriter</code>
* implementation associated with this service provider is able to
! * encode the given <code>RenderedImage</code> instance. Note
* that this includes instances of
! * <code>java.awt.image.BufferedImage</code>.
*
* <p> See the discussion for
! * <code>canEncodeImage(ImageTypeSpecifier)</code> for information
* on the semantics of this method.
*
! * @param im an instance of <code>RenderedImage</code> to be encoded.
*
! * @return <code>true</code> if this writer is likely to be able
* to encode this image.
*
! * @exception IllegalArgumentException if <code>im</code>
! * is <code>null</code>.
*/
public boolean canEncodeImage(RenderedImage im) {
return canEncodeImage(ImageTypeSpecifier.createFromRenderedImage(im));
}
/**
! * Returns an instance of the <code>ImageWriter</code>
* implementation associated with this service provider.
* The returned object will initially be in an initial state as if
! * its <code>reset</code> method had been called.
*
* <p> The default implementation simply returns
! * <code>createWriterInstance(null)</code>.
*
! * @return an <code>ImageWriter</code> instance.
*
* @exception IOException if an error occurs during loading,
* or initialization of the writer class, or during instantiation
* or initialization of the writer object.
*/
public ImageWriter createWriterInstance() throws IOException {
return createWriterInstance(null);
}
/**
! * Returns an instance of the <code>ImageWriter</code>
* implementation associated with this service provider.
* The returned object will initially be in an initial state
! * as if its <code>reset</code> method had been called.
*
! * <p> An <code>Object</code> may be supplied to the plug-in at
* construction time. The nature of the object is entirely
* plug-in specific.
*
* <p> Typically, a plug-in will implement this method using code
! * such as <code>return new MyImageWriter(this)</code>.
*
* @param extension a plug-in specific extension object, which may
! * be <code>null</code>.
*
! * @return an <code>ImageWriter</code> instance.
*
* @exception IOException if the attempt to instantiate
* the writer fails.
* @exception IllegalArgumentException if the
! * <code>ImageWriter</code>'s constructor throws an
! * <code>IllegalArgumentException</code> to indicate that the
* extension object is unsuitable.
*/
public abstract ImageWriter createWriterInstance(Object extension)
throws IOException;
/**
! * Returns <code>true</code> if the <code>ImageWriter</code> object
! * passed in is an instance of the <code>ImageWriter</code>
* associated with this service provider.
*
! * @param writer an <code>ImageWriter</code> instance.
*
! * @return <code>true</code> if <code>writer</code> is recognized
*
! * @exception IllegalArgumentException if <code>writer</code> is
! * <code>null</code>.
*/
public boolean isOwnWriter(ImageWriter writer) {
if (writer == null) {
throw new IllegalArgumentException("writer == null!");
}
String name = writer.getClass().getName();
return name.equals(pluginClassName);
}
/**
! * Returns an array of <code>String</code>s containing all the
! * fully qualified names of all the <code>ImageReaderSpi</code>
* classes that can understand the internal metadata
! * representation used by the <code>ImageWriter</code> associated
! * with this service provider, or <code>null</code> if there are
! * no such <code>ImageReaders</code> specified. If a
! * non-<code>null</code> value is returned, it must have non-zero
* length.
*
* <p> The first item in the array must be the name of the service
* provider for the "preferred" reader, as it will be used to
! * instantiate the <code>ImageReader</code> returned by
! * <code>ImageIO.getImageReader(ImageWriter)</code>.
*
* <p> This mechanism may be used to obtain
! * <code>ImageReaders</code> that will generated non-pixel
! * meta-data (see <code>IIOExtraDataInfo</code>) in a structure
! * understood by an <code>ImageWriter</code>. By reading the
* image and obtaining this data from one of the
! * <code>ImageReaders</code> obtained with this method and passing
! * it on to the <code>ImageWriter</code>, a client program can
* read an image, modify it in some way, and write it back out
* preserving all meta-data, without having to understand anything
* about the internal structure of the meta-data, or even about
* the image format.
*
! * @return an array of <code>String</code>s of length at least 1
! * containing names of <code>ImageReaderSpi</code>s, or
! * <code>null</code>.
*
* @see javax.imageio.ImageIO#getImageReader(ImageWriter)
* @see ImageReaderSpi#getImageWriterSpiNames()
*/
public String[] getImageReaderSpiNames() {
--- 241,436 ----
this.readerSpiNames = readerSpiNames.clone();
}
}
/**
! * Returns {@code true} if the format that this writer
* outputs preserves pixel data bit-accurately. The default
! * implementation returns {@code true}.
*
! * @return {@code true} if the format preserves full pixel
* accuracy.
*/
public boolean isFormatLossless() {
return true;
}
/**
! * Returns an array of {@code Class} objects indicating what
* types of objects may be used as arguments to the writer's
! * {@code setOutput} method.
*
* <p> For most writers, which only output to an
! * {@code ImageOutputStream}, a single-element array
! * containing {@code ImageOutputStream.class} should be
* returned.
*
! * @return a non-{@code null} array of
! * {@code Class} objects of length at least 1.
*/
public Class<?>[] getOutputTypes() {
return outputTypes.clone();
}
/**
! * Returns {@code true} if the {@code ImageWriter}
* implementation associated with this service provider is able to
* encode an image with the given layout. The layout
! * (<i>i.e.</i>, the image's {@code SampleModel} and
! * {@code ColorModel}) is described by an
! * {@code ImageTypeSpecifier} object.
*
! * <p> A return value of {@code true} is not an absolute
* guarantee of successful encoding; the encoding process may still
* produce errors due to factors such as I/O errors, inconsistent
* or malformed data structures, etc. The intent is that a
* reasonable inspection of the basic structure of the image be
* performed in order to determine if it is within the scope of
* the encoding format. For example, a service provider for a
* format that can only encode greyscale would return
! * {@code false} if handed an RGB {@code BufferedImage}.
* Similarly, a service provider for a format that can encode
* 8-bit RGB imagery might refuse to encode an image with an
* associated alpha channel.
*
! * <p> Different {@code ImageWriter}s, and thus service
* providers, may choose to be more or less strict. For example,
* they might accept an image with premultiplied alpha even though
* it will have to be divided out of each pixel, at some loss of
* precision, in order to be stored.
*
! * @param type an {@code ImageTypeSpecifier} specifying the
* layout of the image to be written.
*
! * @return {@code true} if this writer is likely to be able
* to encode images with the given layout.
*
! * @exception IllegalArgumentException if {@code type}
! * is {@code null}.
*/
public abstract boolean canEncodeImage(ImageTypeSpecifier type);
/**
! * Returns {@code true} if the {@code ImageWriter}
* implementation associated with this service provider is able to
! * encode the given {@code RenderedImage} instance. Note
* that this includes instances of
! * {@code java.awt.image.BufferedImage}.
*
* <p> See the discussion for
! * {@code canEncodeImage(ImageTypeSpecifier)} for information
* on the semantics of this method.
*
! * @param im an instance of {@code RenderedImage} to be encoded.
*
! * @return {@code true} if this writer is likely to be able
* to encode this image.
*
! * @exception IllegalArgumentException if {@code im}
! * is {@code null}.
*/
public boolean canEncodeImage(RenderedImage im) {
return canEncodeImage(ImageTypeSpecifier.createFromRenderedImage(im));
}
/**
! * Returns an instance of the {@code ImageWriter}
* implementation associated with this service provider.
* The returned object will initially be in an initial state as if
! * its {@code reset} method had been called.
*
* <p> The default implementation simply returns
! * {@code createWriterInstance(null)}.
*
! * @return an {@code ImageWriter} instance.
*
* @exception IOException if an error occurs during loading,
* or initialization of the writer class, or during instantiation
* or initialization of the writer object.
*/
public ImageWriter createWriterInstance() throws IOException {
return createWriterInstance(null);
}
/**
! * Returns an instance of the {@code ImageWriter}
* implementation associated with this service provider.
* The returned object will initially be in an initial state
! * as if its {@code reset} method had been called.
*
! * <p> An {@code Object} may be supplied to the plug-in at
* construction time. The nature of the object is entirely
* plug-in specific.
*
* <p> Typically, a plug-in will implement this method using code
! * such as {@code return new MyImageWriter(this)}.
*
* @param extension a plug-in specific extension object, which may
! * be {@code null}.
*
! * @return an {@code ImageWriter} instance.
*
* @exception IOException if the attempt to instantiate
* the writer fails.
* @exception IllegalArgumentException if the
! * {@code ImageWriter}'s constructor throws an
! * {@code IllegalArgumentException} to indicate that the
* extension object is unsuitable.
*/
public abstract ImageWriter createWriterInstance(Object extension)
throws IOException;
/**
! * Returns {@code true} if the {@code ImageWriter} object
! * passed in is an instance of the {@code ImageWriter}
* associated with this service provider.
*
! * @param writer an {@code ImageWriter} instance.
*
! * @return {@code true} if {@code writer} is recognized
*
! * @exception IllegalArgumentException if {@code writer} is
! * {@code null}.
*/
public boolean isOwnWriter(ImageWriter writer) {
if (writer == null) {
throw new IllegalArgumentException("writer == null!");
}
String name = writer.getClass().getName();
return name.equals(pluginClassName);
}
/**
! * Returns an array of {@code String}s containing all the
! * fully qualified names of all the {@code ImageReaderSpi}
* classes that can understand the internal metadata
! * representation used by the {@code ImageWriter} associated
! * with this service provider, or {@code null} if there are
! * no such {@code ImageReaders} specified. If a
! * non-{@code null} value is returned, it must have non-zero
* length.
*
* <p> The first item in the array must be the name of the service
* provider for the "preferred" reader, as it will be used to
! * instantiate the {@code ImageReader} returned by
! * {@code ImageIO.getImageReader(ImageWriter)}.
*
* <p> This mechanism may be used to obtain
! * {@code ImageReaders} that will generated non-pixel
! * meta-data (see {@code IIOExtraDataInfo}) in a structure
! * understood by an {@code ImageWriter}. By reading the
* image and obtaining this data from one of the
! * {@code ImageReaders} obtained with this method and passing
! * it on to the {@code ImageWriter}, a client program can
* read an image, modify it in some way, and write it back out
* preserving all meta-data, without having to understand anything
* about the internal structure of the meta-data, or even about
* the image format.
*
! * @return an array of {@code String}s of length at least 1
! * containing names of {@code ImageReaderSpi}s, or
! * {@code null}.
*
* @see javax.imageio.ImageIO#getImageReader(ImageWriter)
* @see ImageReaderSpi#getImageWriterSpiNames()
*/
public String[] getImageReaderSpiNames() {
< prev index next >