jdk/src/java.desktop/share/classes/javax/imageio/spi/ImageReaderWriterSpi.java
changeset 25859 3317bb8137f4
parent 23313 f100f0d49e0b
child 35667 ed476aba94de
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.desktop/share/classes/javax/imageio/spi/ImageReaderWriterSpi.java	Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,601 @@
+/*
+ * Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
+ * 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
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+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
+ * <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
+     * <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
+     * <code>getFileSuffixes</code>, initially <code>null</code>.
+     */
+    protected String[] suffixes = null;
+
+    /**
+     * An array of strings to be returned from
+     * <code>getMIMETypes</code>, initially <code>null</code>.
+     */
+    protected String[] MIMETypes = 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
+     * <code>false</code>.
+     */
+    protected boolean supportsStandardStreamMetadataFormat = false;
+
+    /**
+     * 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 <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 <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 <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
+     * <code>false</code>.
+     */
+    protected boolean supportsStandardImageMetadataFormat = false;
+
+    /**
+     * 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 <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 <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 <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 <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 = names.clone();
+        // If length == 0, leave it null
+        if (suffixes != null && suffixes.length > 0) {
+            this.suffixes = suffixes.clone();
+        }
+        // If length == 0, leave it null
+        if (MIMETypes != null && MIMETypes.length > 0) {
+            this.MIMETypes = 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 =
+                extraStreamMetadataFormatNames.clone();
+        }
+        // If length == 0, leave it null
+        if (extraStreamMetadataFormatClassNames != null &&
+            extraStreamMetadataFormatClassNames.length > 0) {
+            this.extraStreamMetadataFormatClassNames =
+                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 =
+                extraImageMetadataFormatNames.clone();
+        }
+        // If length == 0, leave it null
+        if (extraImageMetadataFormatClassNames != null &&
+            extraImageMetadataFormatClassNames.length > 0) {
+            this.extraImageMetadataFormatClassNames =
+                extraImageMetadataFormatClassNames.clone();
+        }
+    }
+
+    /**
+     * 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 <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 names.clone();
+    }
+
+    /**
+     * 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 : suffixes.clone();
+    }
+
+    /**
+     * 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 : MIMETypes.clone();
+    }
+
+    /**
+     * 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 <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,
+     * <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 <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 : extraStreamMetadataFormatNames.clone();
+    }
+
+    /**
+     * 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,
+     * <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 <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 : extraImageMetadataFormatNames.clone();
+    }
+
+    /**
+     * 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 <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
+     * image 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;
+        }
+    }
+}