/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @author Rustem V. Rafikov
* @version $Revision: 1.3 $
*/
package javax.imageio;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;
import javax.imageio.spi.*;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.Arrays;
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.net.URL;
/**
* The ImageIO class provides static methods to perform reading and writing
* operations using registered ImageReader and ImageWriter objects.
*
* @since Android 1.0
*/
public final class ImageIO {
/**
* The constant registry.
*/
private static final IIORegistry registry = IIORegistry.getDefaultInstance();
/**
* Instantiates a new ImageIO.
*/
private ImageIO() {
}
/**
* Scans for plug-ins in the class path, loads spi classes, and registers
* them with the IIORegistry.
*/
public static void scanForPlugins() {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Sets flag which indicates whether a cache file is used when creating
* ImageInputStreams and ImageOutputStreams or not.
*
* @param useCache
* the use cache flag.
*/
public static void setUseCache(boolean useCache) {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Gets the flag which indicates whether a cache file is used when creating
* ImageInputStreams and ImageOutputStreams or not. This method returns the
* current value which is set by setUseCache method.
*
* @return the use cache flag.
*/
public static boolean getUseCache() {
// TODO implement
return false;
}
/**
* Sets the cache directory.
*
* @param cacheDirectory
* the File which specifies a cache directory.
*/
public static void setCacheDirectory(File cacheDirectory) {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Gets the directory where cache files are created, returned the file which
* is set by setCacheDirectory method, or null.
*
* @return the File object which is set by setCacheDirectory method, or
* null.
*/
public static File getCacheDirectory() {
// TODO implement
// -- null indicates system-dep default temporary directory
return null;
}
/**
* Creates an ImageInputStream from the specified Object. The specified
* Object should obtain the input source such as File, or InputStream.
*
* @param input
* the input Object such as File, or InputStream.
* @return the ImageInputStream object, or null.
* @throws IOException
* if an I/O exception has occurred.
*/
public static ImageInputStream createImageInputStream(Object input) throws IOException {
if (input == null) {
throw new IllegalArgumentException("input source cannot be NULL");
}
Iterator<ImageInputStreamSpi> it = registry.getServiceProviders(ImageInputStreamSpi.class,
true);
while (it.hasNext()) {
ImageInputStreamSpi spi = it.next();
if (spi.getInputClass().isInstance(input)) {
return spi.createInputStreamInstance(input);
}
}
return null;
}
/**
* Creates an ImageOutputStream using the specified Object. The specified
* Object should obtain the output source such as File, or OutputStream.
*
* @param output
* the output Object such as File, or OutputStream.
* @return the ImageOutputStream object, or null.
* @throws IOException
* if an I/O exception has occurred.
*/
public static ImageOutputStream createImageOutputStream(Object output) throws IOException {
if (output == null) {
throw new IllegalArgumentException("output destination cannot be NULL");
}
Iterator<ImageOutputStreamSpi> it = registry.getServiceProviders(
ImageOutputStreamSpi.class, true);
while (it.hasNext()) {
ImageOutputStreamSpi spi = it.next();
if (spi.getOutputClass().isInstance(output)) {
// todo - use getUseCache and getCacheDir here
return spi.createOutputStreamInstance(output);
}
}
return null;
}
/**
* Gets the array of format names as String which can be decoded by
* registered ImageReader objects.
*
* @return the array of format names.
*/
public static String[] getReaderFormatNames() {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Gets the array of MIME types as String which can be decoded by registered
* ImageReader objects.
*
* @return the array of MIME types.
*/
public static String[] getReaderMIMETypes() {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Gets the Iterator of registered ImageReader which are able to decode an
* input data specified by input Object.
*
* @param input
* the input Object with encoded data such as ImageInputStream
* object.
* @return the Iterator of registered ImageReader.
*/
public static Iterator<ImageReader> getImageReaders(Object input) {
if (input == null) {
throw new NullPointerException("input cannot be NULL");
}
Iterator<ImageReaderSpi> it = registry.getServiceProviders(ImageReaderSpi.class,
new CanReadFilter(input), true);
return new SpiIteratorToReadersIteratorWrapper(it);
}
/**
* Gets the Iterator of registered ImageReader which are able to decode the
* specified format.
*
* @param formatName
* the format name such as "jpeg", or "gif".
* @return the Iterator of registered ImageReader.
*/
public static Iterator<ImageReader> getImageReadersByFormatName(String formatName) {
if (formatName == null) {
throw new NullPointerException("format name cannot be NULL");
}
Iterator<ImageReaderSpi> it = registry.getServiceProviders(ImageReaderSpi.class,
new FormatFilter(formatName), true);
return new SpiIteratorToReadersIteratorWrapper(it);
}
/**
* Gets the Iterator which lists the registered ImageReader objects that are
* able to decode files with the specified suffix.
*
* @param fileSuffix
* the file suffix such as "jpg".
* @return the Iterator of registered ImageReaders.
*/
public static Iterator<ImageReader> getImageReadersBySuffix(String fileSuffix) {
if (fileSuffix == null) {
throw new NullPointerException("suffix cannot be NULL");
}
Iterator<ImageReaderSpi> it = registry.getServiceProviders(ImageReaderSpi.class,
new SuffixFilter(fileSuffix), true);
return new SpiIteratorToReadersIteratorWrapper(it);
}
/**
* Gets the Iterator of registered ImageReader objects that are able to
* decode files with the specified MIME type.
*
* @param MIMEType
* the MIME type such as "image/jpeg".
* @return the Iterator of registered ImageReaders.
*/
public static Iterator<ImageReader> getImageReadersByMIMEType(String MIMEType) {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Gets an array of Strings giving the names of the formats supported by
* registered ImageWriter objects.
*
* @return the array of format names.
*/
public static String[] getWriterFormatNames() {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Gets an array of Strings giving the MIME types of the formats supported
* by registered ImageWriter objects.
*
* @return the array of MIME types.
*/
public static String[] getWriterMIMETypes() {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Gets the Iterator which lists the registered ImageReader objects that are
* able to encode the specified image format.
*
* @param formatName
* the image format name such as "jpeg".
* @return the Iterator of registered ImageWriter.
*/
public static Iterator<ImageWriter> getImageWritersByFormatName(String formatName) {
if (formatName == null) {
throw new NullPointerException("format name cannot be NULL");
}
Iterator<ImageWriterSpi> it = registry.getServiceProviders(ImageWriterSpi.class,
new FormatFilter(formatName), true);
return new SpiIteratorToWritersIteratorWrapper(it);
}
/**
* Gets the Iterator which lists the registered ImageReader objects that are
* able to encode the specified suffix.
*
* @param fileSuffix
* the file suffix such as "jpg".
* @return the Iterator of registered ImageWriter.
*/
public static Iterator<ImageWriter> getImageWritersBySuffix(String fileSuffix) {
if (fileSuffix == null) {
throw new NullPointerException("suffix cannot be NULL");
}
Iterator<ImageWriterSpi> it = registry.getServiceProviders(ImageWriterSpi.class,
new SuffixFilter(fileSuffix), true);
return new SpiIteratorToWritersIteratorWrapper(it);
}
/**
* Gets the Iterator which lists the registered ImageReader objects that are
* able to encode the specified MIME type.
*
* @param MIMEType
* the MIME type such as "image/jpeg".
* @return the Iterator of registered ImageWriter.
*/
public static Iterator<ImageWriter> getImageWritersByMIMEType(String MIMEType) {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Gets an ImageWriter object which corresponds to the specified
* ImageReader, or returns null if the specified ImageReader is not
* registered.
*
* @param reader
* the specified ImageReader.
* @return the ImageWriter, or null.
*/
public static ImageWriter getImageWriter(ImageReader reader) {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Gets an ImageReader object which corresponds to the specified
* ImageWriter, or returns null if the specified ImageWriter is not
* registered.
*
* @param writer
* the registered ImageWriter object.
* @return the ImageReader.
*/
public static ImageReader getImageReader(ImageWriter writer) {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Gets the Iterator of ImageWriter objects which are able to encode images
* with the specified ImageTypeSpecifier and format.
*
* @param type
* the ImageTypeSpecifier, which defines layout.
* @param formatName
* the format name.
* @return the Iterator of ImageWriter objects.
*/
public static Iterator<ImageWriter> getImageWriters(ImageTypeSpecifier type, String formatName) {
if (type == null) {
throw new NullPointerException("type cannot be NULL");
}
if (formatName == null) {
throw new NullPointerException("format name cannot be NULL");
}
Iterator<ImageWriterSpi> it = registry.getServiceProviders(ImageWriterSpi.class,
new FormatAndEncodeFilter(type, formatName), true);
return new SpiIteratorToWritersIteratorWrapper(it);
}
/**
* Gets the Iterator of registered ImageTranscoders which are able to
* transcode the metadata of the specified ImageReader object to a suitable
* object for encoding by the specified ImageWriter.
*
* @param reader
* the specified ImageReader.
* @param writer
* the specified ImageWriter.
* @return the Iterator of registered ImageTranscoders.
*/
public static Iterator<ImageTranscoder> getImageTranscoders(ImageReader reader,
ImageWriter writer) {
throw new UnsupportedOperationException("Not supported yet");
}
/**
* Reads image data from the specified File and decodes it using the
* appropriate registered ImageReader object. The File is wrapped in an
* ImageInputStream.
*
* @param input
* the File to be read.
* @return the BufferedImage decoded from the specified File, or null.
* @throws IOException
* if an I/O exception has occurred.
*/
public static BufferedImage read(File input) throws IOException {
if (input == null) {
throw new IllegalArgumentException("input == null!");
}
ImageInputStream stream = createImageInputStream(input);
return read(stream);
}
/**
* Reads image data from the specified InputStream and decodes it using an
* appropriate registered an ImageReader object.
*
* @param input
* the InputStream.
* @return the BufferedImage decoded from the specified InputStream, or
* null.
* @throws IOException
* if an I/O exception has occurred.
*/
public static BufferedImage read(InputStream input) throws IOException {
if (input == null) {
throw new IllegalArgumentException("input == null!");
}
ImageInputStream stream = createImageInputStream(input);
return read(stream);
}
/**
* Reads image data from the specified URL and decodes it using the
* appropriate registered ImageReader object.
*
* @param input
* the URL to be read.
* @return the BufferedImage decoded from the specified URL, or null.
* @throws IOException
* if an I/O exception has occurred.
*/
public static BufferedImage read(URL input) throws IOException {
if (input == null) {
throw new IllegalArgumentException("input == null!");
}
InputStream stream = input.openStream();
BufferedImage res = read(stream);
stream.close();
return res;
}
/**
* Reads image data from the specified ImageInputStream and decodes it using
* appropriate registered an ImageReader object.
*
* @param stream
* the ImageInputStream.
* @return the BufferedImage decoded from the specified ImageInputStream, or
* null.
* @throws IOException
* if an I/O exception has occurred.
*/
public static BufferedImage read(ImageInputStream stream) throws IOException {
if (stream == null) {
throw new IllegalArgumentException("stream == null!");
}
Iterator<ImageReader> imageReaders = getImageReaders(stream);
if (!imageReaders.hasNext()) {
return null;
}
ImageReader reader = imageReaders.next();
reader.setInput(stream, false, true);
BufferedImage res = reader.read(0);
reader.dispose();
try {
stream.close();
} catch (IOException e) {
// Stream could be already closed, proceed silently in this case
}
return res;
}
/**
* Writes the specified image in the specified format (using an appropriate
* ImageWriter) to the specified ImageOutputStream.
*
* @param im
* the RenderedImage.
* @param formatName
* the format name.
* @param output
* the ImageOutputStream where Image to be written.
* @return true, if Image is written successfully, false otherwise.
* @throws IOException
* if an I/O exception has occurred.
*/
public static boolean write(RenderedImage im, String formatName, ImageOutputStream output)
throws IOException {
if (im == null) {
throw new IllegalArgumentException("image cannot be NULL");
}
if (formatName == null) {
throw new IllegalArgumentException("format name cannot be NULL");
}
if (output == null) {
throw new IllegalArgumentException("output cannot be NULL");
}
Iterator<ImageWriter> it = getImageWriters(ImageTypeSpecifier.createFromRenderedImage(im),
formatName);
if (it.hasNext()) {
ImageWriter writer = it.next();
writer.setOutput(output);
writer.write(im);
output.flush();
writer.dispose();
return true;
}
return false;
}
/**
* Writes the specified image in the specified format (using an appropriate
* ImageWriter) to the specified File.
*
* @param im
* the RenderedImage.
* @param formatName
* the format name.
* @param output
* the output File where Image to be written.
* @return true, if Image is written successfully, false otherwise.
* @throws IOException
* if an I/O exception has occurred.
*/
public static boolean write(RenderedImage im, String formatName, File output)
throws IOException {
if (output == null) {
throw new IllegalArgumentException("output cannot be NULL");
}
if (output.exists()) {
output.delete();
}
ImageOutputStream ios = createImageOutputStream(output);
boolean rt = write(im, formatName, ios);
ios.close();
return rt;
}
/**
* Writes the specified image in the specified format (using an appropriate
* ImageWriter) to the specified OutputStream.
*
* @param im
* the RenderedImage.
* @param formatName
* the format name.
* @param output
* the OutputStream where Image is to be written.
* @return true, if Image is written successfully, false otherwise.
* @throws IOException
* if an I/O exception has occurred.
*/
public static boolean write(RenderedImage im, String formatName, OutputStream output)
throws IOException {
if (output == null) {
throw new IllegalArgumentException("output cannot be NULL");
}
ImageOutputStream ios = createImageOutputStream(output);
boolean rt = write(im, formatName, ios);
ios.close();
return rt;
}
/**
* Filter to match spi by format name.
*/
static class FormatFilter implements ServiceRegistry.Filter {
/**
* The name.
*/
private String name;
/**
* Instantiates a new format filter.
*
* @param name
* the name.
*/
public FormatFilter(String name) {
this.name = name;
}
public boolean filter(Object provider) {
ImageReaderWriterSpi spi = (ImageReaderWriterSpi)provider;
return Arrays.asList(spi.getFormatNames()).contains(name);
}
}
/**
* Filter to match spi by format name and encoding possibility.
*/
static class FormatAndEncodeFilter extends FormatFilter {
/**
* The type.
*/
private ImageTypeSpecifier type;
/**
* Instantiates a new format and encode filter.
*
* @param type
* the type.
* @param name
* the name.
*/
public FormatAndEncodeFilter(ImageTypeSpecifier type, String name) {
super(name);
this.type = type;
}
@Override
public boolean filter(Object provider) {
ImageWriterSpi spi = (ImageWriterSpi)provider;
return super.filter(provider) && spi.canEncodeImage(type);
}
}
/**
* Filter to match spi by suffix.
*/
static class SuffixFilter implements ServiceRegistry.Filter {
/**
* The suf.
*/
private String suf;
/**
* Instantiates a new suffix filter.
*
* @param suf
* the suf.
*/
public SuffixFilter(String suf) {
this.suf = suf;
}
public boolean filter(Object provider) {
ImageReaderWriterSpi spi = (ImageReaderWriterSpi)provider;
return Arrays.asList(spi.getFileSuffixes()).contains(suf);
}
}
/**
* Filter to match spi by decoding possibility.
*/
static class CanReadFilter implements ServiceRegistry.Filter {
/**
* The input.
*/
private Object input;
/**
* Instantiates a new can read filter.
*
* @param input
* the input.
*/
public CanReadFilter(Object input) {
this.input = input;
}
public boolean filter(Object provider) {
ImageReaderSpi spi = (ImageReaderSpi)provider;
try {
return spi.canDecodeInput(input);
} catch (IOException e) {
return false;
}
}
}
/**
* Wraps Spi's iterator to ImageWriter iterator.
*/
static class SpiIteratorToWritersIteratorWrapper implements Iterator<ImageWriter> {
/**
* The backend.
*/
private Iterator<ImageWriterSpi> backend;
/**
* Instantiates a new spi iterator to writers iterator wrapper.
*
* @param backend
* the backend.
*/
public SpiIteratorToWritersIteratorWrapper(Iterator<ImageWriterSpi> backend) {
this.backend = backend;
}
/**
* Next.
*
* @return the image writer.
*/
public ImageWriter next() {
try {
return backend.next().createWriterInstance();
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
/**
* Checks for next.
*
* @return true, if successful.
*/
public boolean hasNext() {
return backend.hasNext();
}
/**
* Removes the.
*/
public void remove() {
throw new UnsupportedOperationException(
"Use deregisterServiceprovider instead of Iterator.remove()");
}
}
/**
* Wraps spi's iterator to ImageReader iterator.
*/
static class SpiIteratorToReadersIteratorWrapper implements Iterator<ImageReader> {
/**
* The backend.
*/
private Iterator<ImageReaderSpi> backend;
/**
* Instantiates a new spi iterator to readers iterator wrapper.
*
* @param backend
* the backend.
*/
public SpiIteratorToReadersIteratorWrapper(Iterator<ImageReaderSpi> backend) {
this.backend = backend;
}
/**
* Next.
*
* @return the image reader.
*/
public ImageReader next() {
try {
return backend.next().createReaderInstance();
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
/**
* Checks for next.
*
* @return true, if successful.
*/
public boolean hasNext() {
return backend.hasNext();
}
/**
* Removes the.
*/
public void remove() {
throw new UnsupportedOperationException(
"Use deregisterServiceprovider instead of Iterator.remove()");
}
}
}
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