/* * Copyright (c) 2000, 2004, 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.File;import java.io.IOException;import javax.imageio.stream.ImageInputStream;/** * The service provider interface (SPI) for * <code>ImageInputStream</code>s. For more information on service * provider interfaces, see the class comment for the * <code>IIORegistry</code> class. * * <p> This interface allows arbitrary objects to be "wrapped" by * instances of <code>ImageInputStream</code>. For example, * a particular <code>ImageInputStreamSpi</code> might allow * a generic <code>InputStream</code> to be used as an input source; * another might take input from a <code>URL</code>. * * <p> By treating the creation of <code>ImageInputStream</code>s as a * pluggable service, it becomes possible to handle future input * sources without changing the API. Also, high-performance * implementations of <code>ImageInputStream</code> (for example, * native implementations for a particular platform) can be installed * and used transparently by applications. * * @see IIORegistry * @see javax.imageio.stream.ImageInputStream * */public abstract class ImageInputStreamSpi extends IIOServiceProvider { /** * A <code>Class</code> object indicating the legal object type * for use by the <code>createInputStreamInstance</code> method. */ protected Class<?> inputClass; /** * Constructs a blank <code>ImageInputStreamSpi</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 ImageInputStreamSpi() { } /** * Constructs an <code>ImageInputStreamSpi</code> with a given set * of values. * * @param vendorName the vendor name. * @param version a version identifier. * @param inputClass a <code>Class</code> object indicating the * legal object type for use by the * <code>createInputStreamInstance</code> method. * * @exception IllegalArgumentException if <code>vendorName</code> * is <code>null</code>. * @exception IllegalArgumentException if <code>version</code> * is <code>null</code>. */ public ImageInputStreamSpi(String vendorName, String version, Class<?> inputClass) { super(vendorName, version); this.inputClass = inputClass; } /** * Returns a <code>Class</code> object representing the class or * interface type that must be implemented by an input source in * order to be "wrapped" in an <code>ImageInputStream</code> via * the <code>createInputStreamInstance</code> method. * * <p> Typical return values might include * <code>InputStream.class</code> or <code>URL.class</code>, but * any class may be used. * * @return a <code>Class</code> variable. * * @see #createInputStreamInstance(Object, boolean, File) */ public Class<?> getInputClass() { return inputClass; } /** * Returns <code>true</code> if the <code>ImageInputStream</code> * implementation associated with this service provider can * optionally make use of a cache file for improved performance * and/or memory footrprint. If <code>false</code>, the value of * the <code>useCache</code> argument to * <code>createInputStreamInstance</code> will be ignored. * * <p> The default implementation returns <code>false</code>. * * @return <code>true</code> if a cache file can be used by the * input streams created by this service provider. */ public boolean canUseCacheFile() { return false; } /** * Returns <code>true</code> if the <code>ImageInputStream</code> * implementation associated with this service provider requires * the use of a cache <code>File</code>. If <code>true</code>, * the value of the <code>useCache</code> argument to * <code>createInputStreamInstance</code> will be ignored. * * <p> The default implementation returns <code>false</code>. * * @return <code>true</code> if a cache file is needed by the * input streams created by this service provider. */ public boolean needsCacheFile() { return false; } /** * Returns an instance of the <code>ImageInputStream</code> * implementation associated with this service provider. If the * use of a cache file is optional, the <code>useCache</code> * parameter will be consulted. Where a cache is required, or * not applicable, the value of <code>useCache</code> will be ignored. * * @param input an object of the class type returned by * <code>getInputClass</code>. * @param useCache a <code>boolean</code> indicating whether a * cache file should be used, in cases where it is optional. * @param cacheDir a <code>File</code> indicating where the * cache file should be created, or <code>null</code> to use the * system directory. * * @return an <code>ImageInputStream</code> instance. * * @exception IllegalArgumentException if <code>input</code> is * not an instance of the correct class or is <code>null</code>. * @exception IllegalArgumentException if a cache file is needed * but <code>cacheDir</code> is non-<code>null</code> and is not a * directory. * @exception IOException if a cache file is needed but cannot be * created. * * @see #getInputClass * @see #canUseCacheFile * @see #needsCacheFile */ public abstract ImageInputStream createInputStreamInstance(Object input, boolean useCache, File cacheDir) throws IOException; /** * Returns an instance of the <code>ImageInputStream</code> * implementation associated with this service provider. A cache * file will be created in the system-dependent default * temporary-file directory, if needed. * * @param input an object of the class type returned by * <code>getInputClass</code>. * * @return an <code>ImageInputStream</code> instance. * * @exception IllegalArgumentException if <code>input</code> is * not an instance of the correct class or is <code>null</code>. * @exception IOException if a cache file is needed but cannot be * created. * * @see #getInputClass() */ public ImageInputStream createInputStreamInstance(Object input) throws IOException { return createInputStreamInstance(input, true, null); }}
/*
* Copyright (c) 2000, 2004, 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.File;
import java.io.IOException;
import javax.imageio.stream.ImageInputStream;
/**
* The service provider interface (SPI) for
* <code>ImageInputStream</code>s. For more information on service
* provider interfaces, see the class comment for the
* <code>IIORegistry</code> class.
*
* <p> This interface allows arbitrary objects to be "wrapped" by
* instances of <code>ImageInputStream</code>. For example,
* a particular <code>ImageInputStreamSpi</code> might allow
* a generic <code>InputStream</code> to be used as an input source;
* another might take input from a <code>URL</code>.
*
* <p> By treating the creation of <code>ImageInputStream</code>s as a
* pluggable service, it becomes possible to handle future input
* sources without changing the API. Also, high-performance
* implementations of <code>ImageInputStream</code> (for example,
* native implementations for a particular platform) can be installed
* and used transparently by applications.
*
* @see IIORegistry
* @see javax.imageio.stream.ImageInputStream
*
*/
public abstract class ImageInputStreamSpi extends IIOServiceProvider {
/**
* A <code>Class</code> object indicating the legal object type
* for use by the <code>createInputStreamInstance</code> method.
*/
protected Class<?> inputClass;
/**
* Constructs a blank <code>ImageInputStreamSpi</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 ImageInputStreamSpi() {
}
/**
* Constructs an <code>ImageInputStreamSpi</code> with a given set
* of values.
*
* @param vendorName the vendor name.
* @param version a version identifier.
* @param inputClass a <code>Class</code> object indicating the
* legal object type for use by the
* <code>createInputStreamInstance</code> method.
*
* @exception IllegalArgumentException if <code>vendorName</code>
* is <code>null</code>.
* @exception IllegalArgumentException if <code>version</code>
* is <code>null</code>.
*/
public ImageInputStreamSpi(String vendorName,
String version,
Class<?> inputClass) {
super(vendorName, version);
this.inputClass = inputClass;
}
/**
* Returns a <code>Class</code> object representing the class or
* interface type that must be implemented by an input source in
* order to be "wrapped" in an <code>ImageInputStream</code> via
* the <code>createInputStreamInstance</code> method.
*
* <p> Typical return values might include
* <code>InputStream.class</code> or <code>URL.class</code>, but
* any class may be used.
*
* @return a <code>Class</code> variable.
*
* @see #createInputStreamInstance(Object, boolean, File)
*/
public Class<?> getInputClass() {
return inputClass;
}
/**
* Returns <code>true</code> if the <code>ImageInputStream</code>
* implementation associated with this service provider can
* optionally make use of a cache file for improved performance
* and/or memory footrprint. If <code>false</code>, the value of
* the <code>useCache</code> argument to
* <code>createInputStreamInstance</code> will be ignored.
*
* <p> The default implementation returns <code>false</code>.
*
* @return <code>true</code> if a cache file can be used by the
* input streams created by this service provider.
*/
public boolean canUseCacheFile() {
return false;
}
/**
* Returns <code>true</code> if the <code>ImageInputStream</code>
* implementation associated with this service provider requires
* the use of a cache <code>File</code>. If <code>true</code>,
* the value of the <code>useCache</code> argument to
* <code>createInputStreamInstance</code> will be ignored.
*
* <p> The default implementation returns <code>false</code>.
*
* @return <code>true</code> if a cache file is needed by the
* input streams created by this service provider.
*/
public boolean needsCacheFile() {
return false;
}
/**
* Returns an instance of the <code>ImageInputStream</code>
* implementation associated with this service provider. If the
* use of a cache file is optional, the <code>useCache</code>
* parameter will be consulted. Where a cache is required, or
* not applicable, the value of <code>useCache</code> will be ignored.
*
* @param input an object of the class type returned by
* <code>getInputClass</code>.
* @param useCache a <code>boolean</code> indicating whether a
* cache file should be used, in cases where it is optional.
* @param cacheDir a <code>File</code> indicating where the
* cache file should be created, or <code>null</code> to use the
* system directory.
*
* @return an <code>ImageInputStream</code> instance.
*
* @exception IllegalArgumentException if <code>input</code> is
* not an instance of the correct class or is <code>null</code>.
* @exception IllegalArgumentException if a cache file is needed
* but <code>cacheDir</code> is non-<code>null</code> and is not a
* directory.
* @exception IOException if a cache file is needed but cannot be
* created.
*
* @see #getInputClass
* @see #canUseCacheFile
* @see #needsCacheFile
*/
public abstract ImageInputStream
createInputStreamInstance(Object input,
boolean useCache,
File cacheDir) throws IOException;
/**
* Returns an instance of the <code>ImageInputStream</code>
* implementation associated with this service provider. A cache
* file will be created in the system-dependent default
* temporary-file directory, if needed.
*
* @param input an object of the class type returned by
* <code>getInputClass</code>.
*
* @return an <code>ImageInputStream</code> instance.
*
* @exception IllegalArgumentException if <code>input</code> is
* not an instance of the correct class or is <code>null</code>.
* @exception IOException if a cache file is needed but cannot be
* created.
*
* @see #getInputClass()
*/
public ImageInputStream createInputStreamInstance(Object input)
throws IOException {
return createInputStreamInstance(input, true, null);
}
}