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/* * 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.ImageOutputStream; /** * The service provider interface (SPI) for * <code>ImageOutputStream</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>ImageOutputStream</code>.  For example, a * particular <code>ImageOutputStreamSpi</code> might allow a generic * <code>OutputStream</code> to be used as a destination; another * might output to a <code>File</code> or to a device such as a serial * port. * * <p> By treating the creation of <code>ImageOutputStream</code>s as * a pluggable service, it becomes possible to handle future output * destinations without changing the API.  Also, high-performance * implementations of <code>ImageOutputStream</code> (for example, * native implementations for a particular platform) can be installed * and used transparently by applications. * * @see IIORegistry * @see javax.imageio.stream.ImageOutputStream * */public abstract class ImageOutputStreamSpi extends IIOServiceProvider {     /**     * A <code>Class</code> object indicating the legal object type     * for use by the <code>createInputStreamInstance</code> method.     */    protected Class<?> outputClass;     /**     * Constructs a blank <code>ImageOutputStreamSpi</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 ImageOutputStreamSpi() {    }     /**     * Constructs an <code>ImageOutputStreamSpi</code> with a given     * set of values.     *     * @param vendorName the vendor name.     * @param version a version identifier.     * @param outputClass a <code>Class</code> object indicating the     * legal object type for use by the     * <code>createOutputStreamInstance</code> method.     *     * @exception IllegalArgumentException if <code>vendorName</code>     * is <code>null</code>.     * @exception IllegalArgumentException if <code>version</code>     * is <code>null</code>.    */    public ImageOutputStreamSpi(String vendorName,                                String version,                                Class<?> outputClass) {        super(vendorName, version);        this.outputClass = outputClass;    }     /**     * Returns a <code>Class</code> object representing the class or     * interface type that must be implemented by an output     * destination in order to be "wrapped" in an     * <code>ImageOutputStream</code> via the     * <code>createOutputStreamInstance</code> method.     *     * <p> Typical return values might include     * <code>OutputStream.class</code> or <code>File.class</code>, but     * any class may be used.     *     * @return a <code>Class</code> variable.     *     * @see #createOutputStreamInstance(Object, boolean, File)     */    public Class<?> getOutputClass() {        return outputClass;    }     /**     * Returns <code>true</code> if the <code>ImageOutputStream</code>     * implementation associated with this service provider can     * optionally make use of a cache <code>File</code> for improved     * performance and/or memory footrprint.  If <code>false</code>,     * the value of the <code>cacheFile</code> argument to     * <code>createOutputStreamInstance</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     * output streams created by this service provider.     */    public boolean canUseCacheFile() {        return false;    }     /**     * Returns <code>true</code> if the <code>ImageOutputStream</code>     * implementation associated with this service provider requires     * the use of a cache <code>File</code>.     *     * <p> The default implementation returns <code>false</code>.     *     * @return <code>true</code> if a cache file is needed by the     * output streams created by this service provider.     */    public boolean needsCacheFile() {        return false;    }     /**     * Returns an instance of the <code>ImageOutputStream</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 output an object of the class type returned by     * <code>getOutputClass</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>ImageOutputStream</code> instance.     *     * @exception IllegalArgumentException if <code>output</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 #getOutputClass     */    public abstract        ImageOutputStream createOutputStreamInstance(Object output,                                                     boolean useCache,                                                     File cacheDir)        throws IOException;     /**     * Returns an instance of the <code>ImageOutputStream</code>     * implementation associated with this service provider.  A cache     * file will be created in the system-dependent default     * temporary-file directory, if needed.     *     * @param output an object of the class type returned by     * <code>getOutputClass</code>.     *     * @return an <code>ImageOutputStream</code> instance.     *     * @exception IllegalArgumentException if <code>output</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 #getOutputClass()     */    public ImageOutputStream createOutputStreamInstance(Object output)        throws IOException {        return createOutputStreamInstance(output, true, null);    }}