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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
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 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
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 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package javax.imageio.spi;

import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Iterator;
import javax.imageio.ImageReader;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.metadata.IIOMetadataFormat;
import javax.imageio.metadata.IIOMetadataFormatImpl;
import javax.imageio.stream.ImageInputStream;


A superclass containing instance variables and methods common to
ImageReaderSpi and ImageWriterSpi.

See Also:
/**
 * A superclass containing instance variables and methods common to
 * <code>ImageReaderSpi</code> and <code>ImageWriterSpi</code>.
 *
 * @see IIORegistry
 * @see ImageReaderSpi
 * @see ImageWriterSpi
 *
 */
public abstract class ImageReaderWriterSpi extends IIOServiceProvider {

    
An array of strings to be returned from
getFormatNames, initially null.
Constructors should set this to a non-null value.

/**
     * An array of strings to be returned from
     * <code>getFormatNames</code>, initially <code>null</code>.
     * Constructors should set this to a non-<code>null</code> value.
     */
    protected String[] names = null;

    
An array of strings to be returned from
getFileSuffixes, initially null.

/**
     * An array of strings to be returned from
     * <code>getFileSuffixes</code>, initially <code>null</code>.
     */
    protected String[] suffixes = null;

    
An array of strings to be returned from
getMIMETypes, initially null.

/**
     * An array of strings to be returned from
     * <code>getMIMETypes</code>, initially <code>null</code>.
     */
    protected String[] MIMETypes = null;

    
A String containing the name of the associated
plug-in class, initially null.

/**
     * A <code>String</code> containing the name of the associated
     * plug-in class, initially <code>null</code>.
     */
    protected String pluginClassName = null;

    
A boolean indicating whether this plug-in supports the
standard metadata format for stream metadata, initially
false.

/**
     * A boolean indicating whether this plug-in supports the
     * standard metadata format for stream metadata, initially
     * <code>false</code>.
     */
    protected boolean supportsStandardStreamMetadataFormat = false;

    
A String containing the name of the native stream
metadata format supported by this plug-in, initially
null.

/**
     * A <code>String</code> containing the name of the native stream
     * metadata format supported by this plug-in, initially
     * <code>null</code>.
     */
    protected String nativeStreamMetadataFormatName = null;

    
A String containing the class name of the native
stream metadata format supported by this plug-in, initially
null.

/**
     * A <code>String</code> containing the class name of the native
     * stream metadata format supported by this plug-in, initially
     * <code>null</code>.
     */
    protected String nativeStreamMetadataFormatClassName = null;

    
An array of Strings containing the names of any
additional stream metadata formats supported by this plug-in,
initially null.

/**
     * An array of <code>String</code>s containing the names of any
     * additional stream metadata formats supported by this plug-in,
     * initially <code>null</code>.
     */
    protected String[] extraStreamMetadataFormatNames = null;

    
An array of Strings containing the class names of
any additional stream metadata formats supported by this plug-in,
initially null.

/**
     * An array of <code>String</code>s containing the class names of
     * any additional stream metadata formats supported by this plug-in,
     * initially <code>null</code>.
     */
    protected String[] extraStreamMetadataFormatClassNames = null;

    
A boolean indicating whether this plug-in supports the
standard metadata format for image metadata, initially
false.

/**
     * A boolean indicating whether this plug-in supports the
     * standard metadata format for image metadata, initially
     * <code>false</code>.
     */
    protected boolean supportsStandardImageMetadataFormat = false;

    
A String containing the name of the
native stream metadata format supported by this plug-in,
initially null.

/**
     * A <code>String</code> containing the name of the
     * native stream metadata format supported by this plug-in,
     * initially <code>null</code>.
     */
    protected String nativeImageMetadataFormatName = null;

    
A String containing the class name of the
native stream metadata format supported by this plug-in,
initially null.

/**
     * A <code>String</code> containing the class name of the
     * native stream metadata format supported by this plug-in,
     * initially <code>null</code>.
     */
    protected String nativeImageMetadataFormatClassName = null;

    
An array of Strings containing the names of any
additional image metadata formats supported by this plug-in,
initially null.

/**
     * An array of <code>String</code>s containing the names of any
     * additional image metadata formats supported by this plug-in,
     * initially <code>null</code>.
     */
    protected String[] extraImageMetadataFormatNames = null;

    
An array of Strings containing the class names of
any additional image metadata formats supported by this
plug-in, initially null.

/**
     * An array of <code>String</code>s containing the class names of
     * any additional image metadata formats supported by this
     * plug-in, initially <code>null</code>.
     */
    protected String[] extraImageMetadataFormatClassNames = null;

    
Constructs an ImageReaderWriterSpi with a given
set of values.

Params:
  • vendorName – the vendor name, as a non-null
String.
  • version – a version identifier, as a non-null
String.
  • names – a non-null array of
Strings indicating the format names.  At least one
entry must be present.
  • suffixes – an array of Strings indicating the
common file suffixes.  If no suffixes are defined,
null should be supplied.  An array of length 0
will be normalized to null.
  • MIMETypes – an array of Strings indicating
the format's MIME types.  If no MIME types are defined,
null should be supplied.  An array of length 0
will be normalized to null.
  • pluginClassName – the fully-qualified name of the
associated ImageReader or ImageWriter
class, as a non-null String.
  • supportsStandardStreamMetadataFormat – a
boolean that indicates whether a stream metadata
object can use trees described by the standard metadata format.
  • nativeStreamMetadataFormatName – a
String, or null, to be returned from
getNativeStreamMetadataFormatName.
  • nativeStreamMetadataFormatClassName – a
String, or null, to be used to instantiate
a metadata format object to be returned from
getNativeStreamMetadataFormat.
  • extraStreamMetadataFormatNames – an array of
Strings, or null, to be returned from
getExtraStreamMetadataFormatNames.  An array of length
0 is normalized to null.
  • extraStreamMetadataFormatClassNames – an array of
Strings, or null, to be used to instantiate
a metadata format object to be returned from
getStreamMetadataFormat.  An array of length
0 is normalized to null.
  • supportsStandardImageMetadataFormat – a
boolean that indicates whether an image metadata
object can use trees described by the standard metadata format.
  • nativeImageMetadataFormatName – a
String, or null, to be returned from
getNativeImageMetadataFormatName.
  • nativeImageMetadataFormatClassName – a
String, or null, to be used to instantiate
a metadata format object to be returned from
getNativeImageMetadataFormat.
  • extraImageMetadataFormatNames – an array of
Strings to be returned from
getExtraImageMetadataFormatNames.  An array of length 0
is normalized to null.
  • extraImageMetadataFormatClassNames – an array of
Strings, or null, to be used to instantiate
a metadata format object to be returned from
getImageMetadataFormat.  An array of length
0 is normalized to null.
Throws:
/**
     * Constructs an <code>ImageReaderWriterSpi</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 MIME types are defined,
     * <code>null</code> should be supplied.  An array of length 0
     * will be normalized to <code>null</code>.
     * @param pluginClassName the fully-qualified name of the
     * associated <code>ImageReader</code> or <code>ImageWriter</code>
     * class, as a non-<code>null</code> <code>String</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>pluginClassName</code>
     * is <code>null</code>.
     */
    public ImageReaderWriterSpi(String vendorName,
                                String version,
                                String[] names,
                                String[] suffixes,
                                String[] MIMETypes,
                                String pluginClassName,
                                boolean supportsStandardStreamMetadataFormat,
                                String nativeStreamMetadataFormatName,
                                String nativeStreamMetadataFormatClassName,
                                String[] extraStreamMetadataFormatNames,
                                String[] extraStreamMetadataFormatClassNames,
                                boolean supportsStandardImageMetadataFormat,
                                String nativeImageMetadataFormatName,
                                String nativeImageMetadataFormatClassName,
                                String[] extraImageMetadataFormatNames,
                                String[] extraImageMetadataFormatClassNames) {
        super(vendorName, version);
        if (names == null) {
            throw new IllegalArgumentException("names == null!");
        }
        if (names.length == 0) {
            throw new IllegalArgumentException("names.length == 0!");
        }
        if (pluginClassName == null) {
            throw new IllegalArgumentException("pluginClassName == null!");
        }

        this.names = (String[])names.clone();
        // If length == 0, leave it null
        if (suffixes != null && suffixes.length > 0) {
            this.suffixes = (String[])suffixes.clone();
        }
        // If length == 0, leave it null
        if (MIMETypes != null && MIMETypes.length > 0) {
            this.MIMETypes = (String[])MIMETypes.clone();
        }
        this.pluginClassName = pluginClassName;

        this.supportsStandardStreamMetadataFormat =
            supportsStandardStreamMetadataFormat;
        this.nativeStreamMetadataFormatName = nativeStreamMetadataFormatName;
        this.nativeStreamMetadataFormatClassName =
            nativeStreamMetadataFormatClassName;
        // If length == 0, leave it null
        if (extraStreamMetadataFormatNames != null &&
            extraStreamMetadataFormatNames.length > 0) {
            this.extraStreamMetadataFormatNames =
                (String[])extraStreamMetadataFormatNames.clone();
        }
        // If length == 0, leave it null
        if (extraStreamMetadataFormatClassNames != null &&
            extraStreamMetadataFormatClassNames.length > 0) {
            this.extraStreamMetadataFormatClassNames =
                (String[])extraStreamMetadataFormatClassNames.clone();
        }
        this.supportsStandardImageMetadataFormat =
            supportsStandardImageMetadataFormat;
        this.nativeImageMetadataFormatName = nativeImageMetadataFormatName;
        this.nativeImageMetadataFormatClassName =
            nativeImageMetadataFormatClassName;
        // If length == 0, leave it null
        if (extraImageMetadataFormatNames != null &&
            extraImageMetadataFormatNames.length > 0) {
            this.extraImageMetadataFormatNames =
                (String[])extraImageMetadataFormatNames.clone();
        }
        // If length == 0, leave it null
        if (extraImageMetadataFormatClassNames != null &&
            extraImageMetadataFormatClassNames.length > 0) {
            this.extraImageMetadataFormatClassNames =
                (String[])extraImageMetadataFormatClassNames.clone();
        }
    }

    
Constructs a blank ImageReaderWriterSpi.  It is up
to the subclass to initialize instance variables and/or
override method implementations in order to provide working
versions of all methods.

/**
     * Constructs a blank <code>ImageReaderWriterSpi</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.
     */
    public ImageReaderWriterSpi() {
    }

    
Returns an array of Strings containing
human-readable names for the formats that are generally usable
by the ImageReader or ImageWriter
implementation associated with this service provider.  For
example, a single ImageReader might be able to
process both PBM and PNM files.

Returns:a non-null array of Strings
or length at least 1 containing informal format names
associated with this reader or writer.
/**
     * Returns an array of <code>String</code>s containing
     * human-readable names for the formats that are generally usable
     * by the <code>ImageReader</code> or <code>ImageWriter</code>
     * implementation associated with this service provider.  For
     * example, a single <code>ImageReader</code> might be able to
     * process both PBM and PNM files.
     *
     * @return a non-<code>null</code> array of <code>String</code>s
     * or length at least 1 containing informal format names
     * associated with this reader or writer.
     */
    public String[] getFormatNames() {
        return (String[])names.clone();
    }

    
Returns an array of Strings containing a list of
file suffixes associated with the formats that are generally
usable by the ImageReader or
ImageWriter implementation associated with this
service provider.  For example, a single
ImageReader might be able to process files with
'.pbm' and '.pnm' suffixes, or both '.jpg' and '.jpeg'
suffixes.  If there are no known file suffixes,
null will be returned.

 Returning a particular suffix does not guarantee that files
with that suffix can be processed; it merely indicates that it
may be worthwhile attempting to decode or encode such files
using this service provider.

Returns:an array of Strings or length at least 1
containing common file suffixes associated with this reader or
writer, or null.
/**
     * Returns an array of <code>String</code>s containing a list of
     * file suffixes associated with the formats that are generally
     * usable by the <code>ImageReader</code> or
     * <code>ImageWriter</code> implementation associated with this
     * service provider.  For example, a single
     * <code>ImageReader</code> might be able to process files with
     * '.pbm' and '.pnm' suffixes, or both '.jpg' and '.jpeg'
     * suffixes.  If there are no known file suffixes,
     * <code>null</code> will be returned.
     *
     * <p> Returning a particular suffix does not guarantee that files
     * with that suffix can be processed; it merely indicates that it
     * may be worthwhile attempting to decode or encode such files
     * using this service provider.
     *
     * @return an array of <code>String</code>s or length at least 1
     * containing common file suffixes associated with this reader or
     * writer, or <code>null</code>.
     */
    public String[] getFileSuffixes() {
        return suffixes == null ? null : (String[])suffixes.clone();
    }

    
Returns an array of Strings containing a list of
MIME types associated with the formats that are generally
usable by the ImageReader or
ImageWriter implementation associated with this
service provider.

 Ideally, only a single MIME type would be required in order
to describe a particular format.  However, for several reasons
it is necessary to associate a list of types with each service
provider.  First, many common image file formats do not have
standard MIME types, so a list of commonly used unofficial
names will be required, such as image/x-pbm and
image/x-portable-bitmap.  Some file formats have
official MIME types but may sometimes be referred to using
their previous unofficial designations, such as
image/x-png instead of the official
image/png.  Finally, a single service provider may
be capable of parsing multiple distinct types from the MIME
point of view, for example image/x-xbitmap and
image/x-xpixmap.

 Returning a particular MIME type does not guarantee that
files claiming to be of that type can be processed; it merely
indicates that it may be worthwhile attempting to decode or
encode such files using this service provider.

Returns:an array of Strings or length at least 1
containing MIME types associated with this reader or writer, or
null.
/**
     * Returns an array of <code>String</code>s containing a list of
     * MIME types associated with the formats that are generally
     * usable by the <code>ImageReader</code> or
     * <code>ImageWriter</code> implementation associated with this
     * service provider.
     *
     * <p> Ideally, only a single MIME type would be required in order
     * to describe a particular format.  However, for several reasons
     * it is necessary to associate a list of types with each service
     * provider.  First, many common image file formats do not have
     * standard MIME types, so a list of commonly used unofficial
     * names will be required, such as <code>image/x-pbm</code> and
     * <code>image/x-portable-bitmap</code>.  Some file formats have
     * official MIME types but may sometimes be referred to using
     * their previous unofficial designations, such as
     * <code>image/x-png</code> instead of the official
     * <code>image/png</code>.  Finally, a single service provider may
     * be capable of parsing multiple distinct types from the MIME
     * point of view, for example <code>image/x-xbitmap</code> and
     * <code>image/x-xpixmap</code>.
     *
     * <p> Returning a particular MIME type does not guarantee that
     * files claiming to be of that type can be processed; it merely
     * indicates that it may be worthwhile attempting to decode or
     * encode such files using this service provider.
     *
     * @return an array of <code>String</code>s or length at least 1
     * containing MIME types associated with this reader or writer, or
     * <code>null</code>.
     */
    public String[] getMIMETypes() {
        return MIMETypes == null ? null : (String[])MIMETypes.clone();
    }

    
Returns the fully-qualified class name of the
ImageReader or ImageWriter plug-in
associated with this service provider.

Returns:the class name, as a non-null
String.
/**
     * Returns the fully-qualified class name of the
     * <code>ImageReader</code> or <code>ImageWriter</code> plug-in
     * associated with this service provider.
     *
     * @return the class name, as a non-<code>null</code>
     * <code>String</code>.
     */
    public String getPluginClassName() {
        return pluginClassName;
    }

    
Returns true if the standard metadata format is
among the document formats recognized by the
getAsTree and setFromTree methods on
the stream metadata objects produced or consumed by this
plug-in.

Returns:true if the standard format is supported
for stream metadata.
/**
     * Returns <code>true</code> if the standard metadata format is
     * among the document formats recognized by the
     * <code>getAsTree</code> and <code>setFromTree</code> methods on
     * the stream metadata objects produced or consumed by this
     * plug-in.
     *
     * @return <code>true</code> if the standard format is supported
     * for stream metadata.
     */
    public boolean isStandardStreamMetadataFormatSupported() {
        return supportsStandardStreamMetadataFormat;
    }

    
Returns the name of the "native" stream metadata format for
this plug-in, which typically allows for lossless encoding and
transmission of the stream metadata stored in the format handled by
this plug-in.  If no such format is supported,
nullwill be returned.

 The default implementation returns the
nativeStreamMetadataFormatName instance variable,
which is typically set by the constructor.

Returns:the name of the native stream metadata format, or
null.
/**
     * Returns the name of the "native" stream metadata format for
     * this plug-in, which typically allows for lossless encoding and
     * transmission of the stream metadata stored in the format handled by
     * this plug-in.  If no such format is supported,
     * <code>null</code>will be returned.
     *
     * <p> The default implementation returns the
     * <code>nativeStreamMetadataFormatName</code> instance variable,
     * which is typically set by the constructor.
     *
     * @return the name of the native stream metadata format, or
     * <code>null</code>.
     *
     */
    public String getNativeStreamMetadataFormatName() {
        return nativeStreamMetadataFormatName;
    }

    
Returns an array of Strings containing the names
of additional document formats, other than the native and
standard formats, recognized by the
getAsTree and setFromTree methods on
the stream metadata objects produced or consumed by this
plug-in.

 If the plug-in does not handle metadata, null should be
returned.

 The set of formats may differ according to the particular
images being read or written; this method should indicate all
the additional formats supported by the plug-in under any
circumstances.

 The default implementation returns a clone of the
extraStreamMetadataFormatNames instance variable,
which is typically set by the constructor.

See Also:
Returns:an array of Strings, or null.
/**
     * Returns an array of <code>String</code>s containing the names
     * of additional document formats, other than the native and
     * standard formats, recognized by the
     * <code>getAsTree</code> and <code>setFromTree</code> methods on
     * the stream metadata objects produced or consumed by this
     * plug-in.
     *
     * <p> If the plug-in does not handle metadata, null should be
     * returned.
     *
     * <p> The set of formats may differ according to the particular
     * images being read or written; this method should indicate all
     * the additional formats supported by the plug-in under any
     * circumstances.
     *
     * <p> The default implementation returns a clone of the
     * <code>extraStreamMetadataFormatNames</code> instance variable,
     * which is typically set by the constructor.
     *
     * @return an array of <code>String</code>s, or null.
     *
     * @see IIOMetadata#getMetadataFormatNames
     * @see #getExtraImageMetadataFormatNames
     * @see #getNativeStreamMetadataFormatName
     */
    public String[] getExtraStreamMetadataFormatNames() {
        return extraStreamMetadataFormatNames == null ?
            null : (String[])extraStreamMetadataFormatNames.clone();
    }

    
Returns true if the standard metadata format is
among the document formats recognized by the
getAsTree and setFromTree methods on
the image metadata objects produced or consumed by this
plug-in.

Returns:true if the standard format is supported
for image metadata.
/**
     * Returns <code>true</code> if the standard metadata format is
     * among the document formats recognized by the
     * <code>getAsTree</code> and <code>setFromTree</code> methods on
     * the image metadata objects produced or consumed by this
     * plug-in.
     *
     * @return <code>true</code> if the standard format is supported
     * for image metadata.
     */
    public boolean isStandardImageMetadataFormatSupported() {
        return supportsStandardImageMetadataFormat;
    }

    
Returns the name of the "native" image metadata format for
this plug-in, which typically allows for lossless encoding and
transmission of the image metadata stored in the format handled by
this plug-in.  If no such format is supported,
nullwill be returned.

 The default implementation returns the
nativeImageMetadataFormatName instance variable,
which is typically set by the constructor.

See Also:
Returns:the name of the native image metadata format, or
null.
/**
     * Returns the name of the "native" image metadata format for
     * this plug-in, which typically allows for lossless encoding and
     * transmission of the image metadata stored in the format handled by
     * this plug-in.  If no such format is supported,
     * <code>null</code>will be returned.
     *
     * <p> The default implementation returns the
     * <code>nativeImageMetadataFormatName</code> instance variable,
     * which is typically set by the constructor.
     *
     * @return the name of the native image metadata format, or
     * <code>null</code>.
     *
     * @see #getExtraImageMetadataFormatNames
     */
    public String getNativeImageMetadataFormatName() {
        return nativeImageMetadataFormatName;
    }

    
Returns an array of Strings containing the names
of additional document formats, other than the native and
standard formats, recognized by the
getAsTree and setFromTree methods on
the image metadata objects produced or consumed by this
plug-in.

 If the plug-in does not handle image metadata, null should
be returned.

 The set of formats may differ according to the particular
images being read or written; this method should indicate all
the additional formats supported by the plug-in under any circumstances.

 The default implementation returns a clone of the
extraImageMetadataFormatNames instance variable,
which is typically set by the constructor.

See Also:
Returns:an array of Strings, or null.
/**
     * Returns an array of <code>String</code>s containing the names
     * of additional document formats, other than the native and
     * standard formats, recognized by the
     * <code>getAsTree</code> and <code>setFromTree</code> methods on
     * the image metadata objects produced or consumed by this
     * plug-in.
     *
     * <p> If the plug-in does not handle image metadata, null should
     * be returned.
     *
     * <p> The set of formats may differ according to the particular
     * images being read or written; this method should indicate all
     * the additional formats supported by the plug-in under any circumstances.
     *
     * <p> The default implementation returns a clone of the
     * <code>extraImageMetadataFormatNames</code> instance variable,
     * which is typically set by the constructor.
     *
     * @return an array of <code>String</code>s, or null.
     *
     * @see IIOMetadata#getMetadataFormatNames
     * @see #getExtraStreamMetadataFormatNames
     * @see #getNativeImageMetadataFormatName
     */
    public String[] getExtraImageMetadataFormatNames() {
        return extraImageMetadataFormatNames == null ?
            null : (String[])extraImageMetadataFormatNames.clone();
    }

    
Returns an IIOMetadataFormat object describing the
given stream metadata format, or null if no
description is available.  The supplied name must be the native
stream metadata format name, the standard metadata format name,
or one of those returned by
getExtraStreamMetadataFormatNames.

Params:
  • formatName – the desired stream metadata format.
Throws:
Returns:an IIOMetadataFormat object.
/**
     * Returns an <code>IIOMetadataFormat</code> object describing the
     * given stream metadata format, or <code>null</code> if no
     * description is available.  The supplied name must be the native
     * stream metadata format name, the standard metadata format name,
     * or one of those returned by
     * <code>getExtraStreamMetadataFormatNames</code>.
     *
     * @param formatName the desired stream metadata format.
     *
     * @return an <code>IIOMetadataFormat</code> object.
     *
     * @exception IllegalArgumentException if <code>formatName</code>
     * is <code>null</code> or is not a supported name.
     */
    public IIOMetadataFormat getStreamMetadataFormat(String formatName) {
        return getMetadataFormat(formatName,
                                 supportsStandardStreamMetadataFormat,
                                 nativeStreamMetadataFormatName,
                                 nativeStreamMetadataFormatClassName,
                                 extraStreamMetadataFormatNames,
                                 extraStreamMetadataFormatClassNames);
    }

    
Returns an IIOMetadataFormat object describing the
given image metadata format, or null if no
description is available.  The supplied name must be the native
iamge metadata format name, the standard metadata format name,
or one of those returned by
getExtraImageMetadataFormatNames.

Params:
  • formatName – the desired image metadata format.
Throws:
Returns:an IIOMetadataFormat object.
/**
     * Returns an <code>IIOMetadataFormat</code> object describing the
     * given image metadata format, or <code>null</code> if no
     * description is available.  The supplied name must be the native
     * iamge metadata format name, the standard metadata format name,
     * or one of those returned by
     * <code>getExtraImageMetadataFormatNames</code>.
     *
     * @param formatName the desired image metadata format.
     *
     * @return an <code>IIOMetadataFormat</code> object.
     *
     * @exception IllegalArgumentException if <code>formatName</code>
     * is <code>null</code> or is not a supported name.
     */
    public IIOMetadataFormat getImageMetadataFormat(String formatName) {
        return getMetadataFormat(formatName,
                                 supportsStandardImageMetadataFormat,
                                 nativeImageMetadataFormatName,
                                 nativeImageMetadataFormatClassName,
                                 extraImageMetadataFormatNames,
                                 extraImageMetadataFormatClassNames);
    }

    private IIOMetadataFormat getMetadataFormat(String formatName,
                                                boolean supportsStandard,
                                                String nativeName,
                                                String nativeClassName,
                                                String [] extraNames,
                                                String [] extraClassNames) {
        if (formatName == null) {
            throw new IllegalArgumentException("formatName == null!");
        }
        if (supportsStandard && formatName.equals
                (IIOMetadataFormatImpl.standardMetadataFormatName)) {

            return IIOMetadataFormatImpl.getStandardFormatInstance();
        }
        String formatClassName = null;
        if (formatName.equals(nativeName)) {
            formatClassName = nativeClassName;
        } else if (extraNames != null) {
            for (int i = 0; i < extraNames.length; i++) {
                if (formatName.equals(extraNames[i])) {
                    formatClassName = extraClassNames[i];
                    break;  // out of for
                }
            }
        }
        if (formatClassName == null) {
            throw new IllegalArgumentException("Unsupported format name");
        }
        try {
            Class cls = Class.forName(formatClassName, true,
                                      ClassLoader.getSystemClassLoader());
            Method meth = cls.getMethod("getInstance");
            return (IIOMetadataFormat) meth.invoke(null);
        } catch (Exception e) {
            RuntimeException ex =
                new IllegalStateException ("Can't obtain format");
            ex.initCause(e);
            throw ex;
        }
    }
}