J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2005 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.imageio; |
| 27 | |
| 28 | import java.awt.image.BufferedImage; |
| 29 | import java.awt.image.RenderedImage; |
| 30 | import java.io.File; |
| 31 | import java.io.InputStream; |
| 32 | import java.io.IOException; |
| 33 | import java.io.OutputStream; |
| 34 | import java.lang.reflect.Method; |
| 35 | import java.net.URL; |
| 36 | import java.security.AccessController; |
| 37 | import java.util.Arrays; |
| 38 | import java.util.Collections; |
| 39 | import java.util.HashSet; |
| 40 | import java.util.Iterator; |
| 41 | import java.util.NoSuchElementException; |
| 42 | import java.util.Set; |
| 43 | import javax.imageio.spi.IIORegistry; |
| 44 | import javax.imageio.spi.ImageReaderSpi; |
| 45 | import javax.imageio.spi.ImageReaderWriterSpi; |
| 46 | import javax.imageio.spi.ImageWriterSpi; |
| 47 | import javax.imageio.spi.ImageInputStreamSpi; |
| 48 | import javax.imageio.spi.ImageOutputStreamSpi; |
| 49 | import javax.imageio.spi.ImageTranscoderSpi; |
| 50 | import javax.imageio.spi.ServiceRegistry; |
| 51 | import javax.imageio.stream.ImageInputStream; |
| 52 | import javax.imageio.stream.ImageOutputStream; |
| 53 | import sun.awt.AppContext; |
| 54 | import sun.security.action.GetPropertyAction; |
| 55 | |
| 56 | /** |
| 57 | * A class containing static convenience methods for locating |
| 58 | * <code>ImageReader</code>s and <code>ImageWriter</code>s, and |
| 59 | * performing simple encoding and decoding. |
| 60 | * |
| 61 | */ |
| 62 | public final class ImageIO { |
| 63 | |
| 64 | private static final IIORegistry theRegistry = |
| 65 | IIORegistry.getDefaultInstance(); |
| 66 | |
| 67 | /** |
| 68 | * Constructor is private to prevent instantiation. |
| 69 | */ |
| 70 | private ImageIO() {} |
| 71 | |
| 72 | /** |
| 73 | * Scans for plug-ins on the application class path, |
| 74 | * loads their service provider classes, and registers a service |
| 75 | * provider instance for each one found with the |
| 76 | * <code>IIORegistry</code>. |
| 77 | * |
| 78 | * <p>This method is needed because the application class path can |
| 79 | * theoretically change, or additional plug-ins may become available. |
| 80 | * Rather than re-scanning the classpath on every invocation of the |
| 81 | * API, the class path is scanned automatically only on the first |
| 82 | * invocation. Clients can call this method to prompt a re-scan. |
| 83 | * Thus this method need only be invoked by sophisticated applications |
| 84 | * which dynamically make new plug-ins available at runtime. |
| 85 | * |
| 86 | * <p> The <code>getResources</code> method of the context |
| 87 | * <code>ClassLoader</code> is used locate JAR files containing |
| 88 | * files named |
| 89 | * <code>META-INF/services/javax.imageio.spi.</code><i>classname</i>, |
| 90 | * where <i>classname</i> is one of <code>ImageReaderSpi</code>, |
| 91 | * <code>ImageWriterSpi</code>, <code>ImageTranscoderSpi</code>, |
| 92 | * <code>ImageInputStreamSpi</code>, or |
| 93 | * <code>ImageOutputStreamSpi</code>, along the application class |
| 94 | * path. |
| 95 | * |
| 96 | * <p> The contents of the located files indicate the names of |
| 97 | * actual implementation classes which implement the |
| 98 | * aforementioned service provider interfaces; the default class |
| 99 | * loader is then used to load each of these classes and to |
| 100 | * instantiate an instance of each class, which is then placed |
| 101 | * into the registry for later retrieval. |
| 102 | * |
| 103 | * <p> The exact set of locations searched depends on the |
| 104 | * implementation of the Java runtime enviroment. |
| 105 | * |
| 106 | * @see ClassLoader#getResources |
| 107 | */ |
| 108 | public static void scanForPlugins() { |
| 109 | theRegistry.registerApplicationClasspathSpis(); |
| 110 | } |
| 111 | |
| 112 | // ImageInputStreams |
| 113 | |
| 114 | /** |
| 115 | * A class to hold information about caching. Each |
| 116 | * <code>ThreadGroup</code> will have its own copy |
| 117 | * via the <code>AppContext</code> mechanism. |
| 118 | */ |
| 119 | static class CacheInfo { |
| 120 | boolean useCache = true; |
| 121 | File cacheDirectory = null; |
| 122 | Boolean hasPermission = null; |
| 123 | |
| 124 | public CacheInfo() {} |
| 125 | |
| 126 | public boolean getUseCache() { |
| 127 | return useCache; |
| 128 | } |
| 129 | |
| 130 | public void setUseCache(boolean useCache) { |
| 131 | this.useCache = useCache; |
| 132 | } |
| 133 | |
| 134 | public File getCacheDirectory() { |
| 135 | return cacheDirectory; |
| 136 | } |
| 137 | |
| 138 | public void setCacheDirectory(File cacheDirectory) { |
| 139 | this.cacheDirectory = cacheDirectory; |
| 140 | } |
| 141 | |
| 142 | public Boolean getHasPermission() { |
| 143 | return hasPermission; |
| 144 | } |
| 145 | |
| 146 | public void setHasPermission(Boolean hasPermission) { |
| 147 | this.hasPermission = hasPermission; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | /** |
| 152 | * Returns the <code>CacheInfo</code> object associated with this |
| 153 | * <code>ThreadGroup</code>. |
| 154 | */ |
| 155 | private static synchronized CacheInfo getCacheInfo() { |
| 156 | AppContext context = AppContext.getAppContext(); |
| 157 | CacheInfo info = (CacheInfo)context.get(CacheInfo.class); |
| 158 | if (info == null) { |
| 159 | info = new CacheInfo(); |
| 160 | context.put(CacheInfo.class, info); |
| 161 | } |
| 162 | return info; |
| 163 | } |
| 164 | |
| 165 | /** |
| 166 | * Returns the default temporary (cache) directory as defined by the |
| 167 | * java.io.tmpdir system property. |
| 168 | */ |
| 169 | private static String getTempDir() { |
| 170 | GetPropertyAction a = new GetPropertyAction("java.io.tmpdir"); |
| 171 | return (String)AccessController.doPrivileged(a); |
| 172 | } |
| 173 | |
| 174 | /** |
| 175 | * Determines whether the caller has write access to the cache |
| 176 | * directory, stores the result in the <code>CacheInfo</code> object, |
| 177 | * and returns the decision. This method helps to prevent mysterious |
| 178 | * SecurityExceptions to be thrown when this convenience class is used |
| 179 | * in an applet, for example. |
| 180 | */ |
| 181 | private static boolean hasCachePermission() { |
| 182 | Boolean hasPermission = getCacheInfo().getHasPermission(); |
| 183 | |
| 184 | if (hasPermission != null) { |
| 185 | return hasPermission.booleanValue(); |
| 186 | } else { |
| 187 | try { |
| 188 | SecurityManager security = System.getSecurityManager(); |
| 189 | if (security != null) { |
| 190 | File cachedir = getCacheDirectory(); |
| 191 | String cachepath; |
| 192 | |
| 193 | if (cachedir != null) { |
| 194 | cachepath = cachedir.getPath(); |
| 195 | } else { |
| 196 | cachepath = getTempDir(); |
| 197 | |
| 198 | if (cachepath == null) { |
| 199 | getCacheInfo().setHasPermission(Boolean.FALSE); |
| 200 | return false; |
| 201 | } |
| 202 | } |
| 203 | |
| 204 | security.checkWrite(cachepath); |
| 205 | } |
| 206 | } catch (SecurityException e) { |
| 207 | getCacheInfo().setHasPermission(Boolean.FALSE); |
| 208 | return false; |
| 209 | } |
| 210 | |
| 211 | getCacheInfo().setHasPermission(Boolean.TRUE); |
| 212 | return true; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * Sets a flag indicating whether a disk-based cache file should |
| 218 | * be used when creating <code>ImageInputStream</code>s and |
| 219 | * <code>ImageOutputStream</code>s. |
| 220 | * |
| 221 | * <p> When reading from a standard <code>InputStream</code>>, it |
| 222 | * may be necessary to save previously read information in a cache |
| 223 | * since the underlying stream does not allow data to be re-read. |
| 224 | * Similarly, when writing to a standard |
| 225 | * <code>OutputStream</code>, a cache may be used to allow a |
| 226 | * previously written value to be changed before flushing it to |
| 227 | * the final destination. |
| 228 | * |
| 229 | * <p> The cache may reside in main memory or on disk. Setting |
| 230 | * this flag to <code>false</code> disallows the use of disk for |
| 231 | * future streams, which may be advantageous when working with |
| 232 | * small images, as the overhead of creating and destroying files |
| 233 | * is removed. |
| 234 | * |
| 235 | * <p> On startup, the value is set to <code>true</code>. |
| 236 | * |
| 237 | * @param useCache a <code>boolean</code> indicating whether a |
| 238 | * cache file should be used, in cases where it is optional. |
| 239 | * |
| 240 | * @see #getUseCache |
| 241 | */ |
| 242 | public static void setUseCache(boolean useCache) { |
| 243 | getCacheInfo().setUseCache(useCache); |
| 244 | } |
| 245 | |
| 246 | /** |
| 247 | * Returns the current value set by <code>setUseCache</code>, or |
| 248 | * <code>true</code> if no explicit setting has been made. |
| 249 | * |
| 250 | * @return true if a disk-based cache may be used for |
| 251 | * <code>ImageInputStream</code>s and |
| 252 | * <code>ImageOutputStream</code>s. |
| 253 | * |
| 254 | * @see #setUseCache |
| 255 | */ |
| 256 | public static boolean getUseCache() { |
| 257 | return getCacheInfo().getUseCache(); |
| 258 | } |
| 259 | |
| 260 | /** |
| 261 | * Sets the directory where cache files are to be created. A |
| 262 | * value of <code>null</code> indicates that the system-dependent |
| 263 | * default temporary-file directory is to be used. If |
| 264 | * <code>getUseCache</code> returns false, this value is ignored. |
| 265 | * |
| 266 | * @param cacheDirectory a <code>File</code> specifying a directory. |
| 267 | * |
| 268 | * @see File#createTempFile(String, String, File) |
| 269 | * |
| 270 | * @exception SecurityException if the security manager denies |
| 271 | * access to the directory. |
| 272 | * @exception IllegalArgumentException if <code>cacheDir</code> is |
| 273 | * non-<code>null</code> but is not a directory. |
| 274 | * |
| 275 | * @see #getCacheDirectory |
| 276 | */ |
| 277 | public static void setCacheDirectory(File cacheDirectory) { |
| 278 | if ((cacheDirectory != null) && !(cacheDirectory.isDirectory())) { |
| 279 | throw new IllegalArgumentException("Not a directory!"); |
| 280 | } |
| 281 | getCacheInfo().setCacheDirectory(cacheDirectory); |
| 282 | getCacheInfo().setHasPermission(null); |
| 283 | } |
| 284 | |
| 285 | /** |
| 286 | * Returns the current value set by |
| 287 | * <code>setCacheDirectory</code>, or <code>null</code> if no |
| 288 | * explicit setting has been made. |
| 289 | * |
| 290 | * @return a <code>File</code> indicating the directory where |
| 291 | * cache files will be created, or <code>null</code> to indicate |
| 292 | * the system-dependent default temporary-file directory. |
| 293 | * |
| 294 | * @see #setCacheDirectory |
| 295 | */ |
| 296 | public static File getCacheDirectory() { |
| 297 | return getCacheInfo().getCacheDirectory(); |
| 298 | } |
| 299 | |
| 300 | /** |
| 301 | * Returns an <code>ImageInputStream</code> that will take its |
| 302 | * input from the given <code>Object</code>. The set of |
| 303 | * <code>ImageInputStreamSpi</code>s registered with the |
| 304 | * <code>IIORegistry</code> class is queried and the first one |
| 305 | * that is able to take input from the supplied object is used to |
| 306 | * create the returned <code>ImageInputStream</code>. If no |
| 307 | * suitable <code>ImageInputStreamSpi</code> exists, |
| 308 | * <code>null</code> is returned. |
| 309 | * |
| 310 | * <p> The current cache settings from <code>getUseCache</code>and |
| 311 | * <code>getCacheDirectory</code> will be used to control caching. |
| 312 | * |
| 313 | * @param input an <code>Object</code> to be used as an input |
| 314 | * source, such as a <code>File</code>, readable |
| 315 | * <code>RandomAccessFile</code>, or <code>InputStream</code>. |
| 316 | * |
| 317 | * @return an <code>ImageInputStream</code>, or <code>null</code>. |
| 318 | * |
| 319 | * @exception IllegalArgumentException if <code>input</code> |
| 320 | * is <code>null</code>. |
| 321 | * @exception IOException if a cache file is needed but cannot be |
| 322 | * created. |
| 323 | * |
| 324 | * @see javax.imageio.spi.ImageInputStreamSpi |
| 325 | */ |
| 326 | public static ImageInputStream createImageInputStream(Object input) |
| 327 | throws IOException { |
| 328 | if (input == null) { |
| 329 | throw new IllegalArgumentException("input == null!"); |
| 330 | } |
| 331 | |
| 332 | Iterator iter; |
| 333 | // Ensure category is present |
| 334 | try { |
| 335 | iter = theRegistry.getServiceProviders(ImageInputStreamSpi.class, |
| 336 | true); |
| 337 | } catch (IllegalArgumentException e) { |
| 338 | return null; |
| 339 | } |
| 340 | |
| 341 | boolean usecache = getUseCache() && hasCachePermission(); |
| 342 | |
| 343 | while (iter.hasNext()) { |
| 344 | ImageInputStreamSpi spi = (ImageInputStreamSpi)iter.next(); |
| 345 | if (spi.getInputClass().isInstance(input)) { |
| 346 | try { |
| 347 | return spi.createInputStreamInstance(input, |
| 348 | usecache, |
| 349 | getCacheDirectory()); |
| 350 | } catch (IOException e) { |
| 351 | throw new IIOException("Can't create cache file!", e); |
| 352 | } |
| 353 | } |
| 354 | } |
| 355 | |
| 356 | return null; |
| 357 | } |
| 358 | |
| 359 | // ImageOutputStreams |
| 360 | |
| 361 | /** |
| 362 | * Returns an <code>ImageOutputStream</code> that will send its |
| 363 | * output to the given <code>Object</code>. The set of |
| 364 | * <code>ImageOutputStreamSpi</code>s registered with the |
| 365 | * <code>IIORegistry</code> class is queried and the first one |
| 366 | * that is able to send output from the supplied object is used to |
| 367 | * create the returned <code>ImageOutputStream</code>. If no |
| 368 | * suitable <code>ImageOutputStreamSpi</code> exists, |
| 369 | * <code>null</code> is returned. |
| 370 | * |
| 371 | * <p> The current cache settings from <code>getUseCache</code>and |
| 372 | * <code>getCacheDirectory</code> will be used to control caching. |
| 373 | * |
| 374 | * @param output an <code>Object</code> to be used as an output |
| 375 | * destination, such as a <code>File</code>, writable |
| 376 | * <code>RandomAccessFile</code>, or <code>OutputStream</code>. |
| 377 | * |
| 378 | * @return an <code>ImageOutputStream</code>, or |
| 379 | * <code>null</code>. |
| 380 | * |
| 381 | * @exception IllegalArgumentException if <code>output</code> is |
| 382 | * <code>null</code>. |
| 383 | * @exception IOException if a cache file is needed but cannot be |
| 384 | * created. |
| 385 | * |
| 386 | * @see javax.imageio.spi.ImageOutputStreamSpi |
| 387 | */ |
| 388 | public static ImageOutputStream createImageOutputStream(Object output) |
| 389 | throws IOException { |
| 390 | if (output == null) { |
| 391 | throw new IllegalArgumentException("output == null!"); |
| 392 | } |
| 393 | |
| 394 | Iterator iter; |
| 395 | // Ensure category is present |
| 396 | try { |
| 397 | iter = theRegistry.getServiceProviders(ImageOutputStreamSpi.class, |
| 398 | true); |
| 399 | } catch (IllegalArgumentException e) { |
| 400 | return null; |
| 401 | } |
| 402 | |
| 403 | boolean usecache = getUseCache() && hasCachePermission(); |
| 404 | |
| 405 | while (iter.hasNext()) { |
| 406 | ImageOutputStreamSpi spi = (ImageOutputStreamSpi)iter.next(); |
| 407 | if (spi.getOutputClass().isInstance(output)) { |
| 408 | try { |
| 409 | return spi.createOutputStreamInstance(output, |
| 410 | usecache, |
| 411 | getCacheDirectory()); |
| 412 | } catch (IOException e) { |
| 413 | throw new IIOException("Can't create cache file!", e); |
| 414 | } |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | return null; |
| 419 | } |
| 420 | |
| 421 | private static enum SpiInfo { |
| 422 | FORMAT_NAMES { |
| 423 | @Override |
| 424 | String[] info(ImageReaderWriterSpi spi) { |
| 425 | return spi.getFormatNames(); |
| 426 | } |
| 427 | }, |
| 428 | MIME_TYPES { |
| 429 | @Override |
| 430 | String[] info(ImageReaderWriterSpi spi) { |
| 431 | return spi.getMIMETypes(); |
| 432 | } |
| 433 | }, |
| 434 | FILE_SUFFIXES { |
| 435 | @Override |
| 436 | String[] info(ImageReaderWriterSpi spi) { |
| 437 | return spi.getFileSuffixes(); |
| 438 | } |
| 439 | }; |
| 440 | |
| 441 | abstract String[] info(ImageReaderWriterSpi spi); |
| 442 | } |
| 443 | |
| 444 | private static <S extends ImageReaderWriterSpi> |
| 445 | String[] getReaderWriterInfo(Class<S> spiClass, SpiInfo spiInfo) |
| 446 | { |
| 447 | // Ensure category is present |
| 448 | Iterator<S> iter; |
| 449 | try { |
| 450 | iter = theRegistry.getServiceProviders(spiClass, true); |
| 451 | } catch (IllegalArgumentException e) { |
| 452 | return new String[0]; |
| 453 | } |
| 454 | |
| 455 | HashSet<String> s = new HashSet<String>(); |
| 456 | while (iter.hasNext()) { |
| 457 | ImageReaderWriterSpi spi = iter.next(); |
| 458 | Collections.addAll(s, spiInfo.info(spi)); |
| 459 | } |
| 460 | |
| 461 | return s.toArray(new String[s.size()]); |
| 462 | } |
| 463 | |
| 464 | // Readers |
| 465 | |
| 466 | /** |
| 467 | * Returns an array of <code>String</code>s listing all of the |
| 468 | * informal format names understood by the current set of registered |
| 469 | * readers. |
| 470 | * |
| 471 | * @return an array of <code>String</code>s. |
| 472 | */ |
| 473 | public static String[] getReaderFormatNames() { |
| 474 | return getReaderWriterInfo(ImageReaderSpi.class, |
| 475 | SpiInfo.FORMAT_NAMES); |
| 476 | } |
| 477 | |
| 478 | /** |
| 479 | * Returns an array of <code>String</code>s listing all of the |
| 480 | * MIME types understood by the current set of registered |
| 481 | * readers. |
| 482 | * |
| 483 | * @return an array of <code>String</code>s. |
| 484 | */ |
| 485 | public static String[] getReaderMIMETypes() { |
| 486 | return getReaderWriterInfo(ImageReaderSpi.class, |
| 487 | SpiInfo.MIME_TYPES); |
| 488 | } |
| 489 | |
| 490 | /** |
| 491 | * Returns an array of <code>String</code>s listing all of the |
| 492 | * file suffixes associated with the formats understood |
| 493 | * by the current set of registered readers. |
| 494 | * |
| 495 | * @return an array of <code>String</code>s. |
| 496 | * @since 1.6 |
| 497 | */ |
| 498 | public static String[] getReaderFileSuffixes() { |
| 499 | return getReaderWriterInfo(ImageReaderSpi.class, |
| 500 | SpiInfo.FILE_SUFFIXES); |
| 501 | } |
| 502 | |
| 503 | static class ImageReaderIterator implements Iterator<ImageReader> { |
| 504 | // Contains ImageReaderSpis |
| 505 | public Iterator iter; |
| 506 | |
| 507 | public ImageReaderIterator(Iterator iter) { |
| 508 | this.iter = iter; |
| 509 | } |
| 510 | |
| 511 | public boolean hasNext() { |
| 512 | return iter.hasNext(); |
| 513 | } |
| 514 | |
| 515 | public ImageReader next() { |
| 516 | ImageReaderSpi spi = null; |
| 517 | try { |
| 518 | spi = (ImageReaderSpi)iter.next(); |
| 519 | return spi.createReaderInstance(); |
| 520 | } catch (IOException e) { |
| 521 | // Deregister the spi in this case, but only as |
| 522 | // an ImageReaderSpi |
| 523 | theRegistry.deregisterServiceProvider(spi, ImageReaderSpi.class); |
| 524 | } |
| 525 | return null; |
| 526 | } |
| 527 | |
| 528 | public void remove() { |
| 529 | throw new UnsupportedOperationException(); |
| 530 | } |
| 531 | } |
| 532 | |
| 533 | static class CanDecodeInputFilter |
| 534 | implements ServiceRegistry.Filter { |
| 535 | |
| 536 | Object input; |
| 537 | |
| 538 | public CanDecodeInputFilter(Object input) { |
| 539 | this.input = input; |
| 540 | } |
| 541 | |
| 542 | public boolean filter(Object elt) { |
| 543 | try { |
| 544 | ImageReaderSpi spi = (ImageReaderSpi)elt; |
| 545 | ImageInputStream stream = null; |
| 546 | if (input instanceof ImageInputStream) { |
| 547 | stream = (ImageInputStream)input; |
| 548 | } |
| 549 | |
| 550 | // Perform mark/reset as a defensive measure |
| 551 | // even though plug-ins are supposed to take |
| 552 | // care of it. |
| 553 | boolean canDecode = false; |
| 554 | if (stream != null) { |
| 555 | stream.mark(); |
| 556 | } |
| 557 | canDecode = spi.canDecodeInput(input); |
| 558 | if (stream != null) { |
| 559 | stream.reset(); |
| 560 | } |
| 561 | |
| 562 | return canDecode; |
| 563 | } catch (IOException e) { |
| 564 | return false; |
| 565 | } |
| 566 | } |
| 567 | } |
| 568 | |
| 569 | static class CanEncodeImageAndFormatFilter |
| 570 | implements ServiceRegistry.Filter { |
| 571 | |
| 572 | ImageTypeSpecifier type; |
| 573 | String formatName; |
| 574 | |
| 575 | public CanEncodeImageAndFormatFilter(ImageTypeSpecifier type, |
| 576 | String formatName) { |
| 577 | this.type = type; |
| 578 | this.formatName = formatName; |
| 579 | } |
| 580 | |
| 581 | public boolean filter(Object elt) { |
| 582 | ImageWriterSpi spi = (ImageWriterSpi)elt; |
| 583 | return Arrays.asList(spi.getFormatNames()).contains(formatName) && |
| 584 | spi.canEncodeImage(type); |
| 585 | } |
| 586 | } |
| 587 | |
| 588 | static class ContainsFilter |
| 589 | implements ServiceRegistry.Filter { |
| 590 | |
| 591 | Method method; |
| 592 | String name; |
| 593 | |
| 594 | // method returns an array of Strings |
| 595 | public ContainsFilter(Method method, |
| 596 | String name) { |
| 597 | this.method = method; |
| 598 | this.name = name; |
| 599 | } |
| 600 | |
| 601 | public boolean filter(Object elt) { |
| 602 | try { |
| 603 | return contains((String[])method.invoke(elt), name); |
| 604 | } catch (Exception e) { |
| 605 | return false; |
| 606 | } |
| 607 | } |
| 608 | } |
| 609 | |
| 610 | /** |
| 611 | * Returns an <code>Iterator</code> containing all currently |
| 612 | * registered <code>ImageReader</code>s that claim to be able to |
| 613 | * decode the supplied <code>Object</code>, typically an |
| 614 | * <code>ImageInputStream</code>. |
| 615 | * |
| 616 | * <p> The stream position is left at its prior position upon |
| 617 | * exit from this method. |
| 618 | * |
| 619 | * @param input an <code>ImageInputStream</code> or other |
| 620 | * <code>Object</code> containing encoded image data. |
| 621 | * |
| 622 | * @return an <code>Iterator</code> containing <code>ImageReader</code>s. |
| 623 | * |
| 624 | * @exception IllegalArgumentException if <code>input</code> is |
| 625 | * <code>null</code>. |
| 626 | * |
| 627 | * @see javax.imageio.spi.ImageReaderSpi#canDecodeInput |
| 628 | */ |
| 629 | public static Iterator<ImageReader> getImageReaders(Object input) { |
| 630 | if (input == null) { |
| 631 | throw new IllegalArgumentException("input == null!"); |
| 632 | } |
| 633 | Iterator iter; |
| 634 | // Ensure category is present |
| 635 | try { |
| 636 | iter = theRegistry.getServiceProviders(ImageReaderSpi.class, |
| 637 | new CanDecodeInputFilter(input), |
| 638 | true); |
| 639 | } catch (IllegalArgumentException e) { |
| 640 | return Collections.emptyIterator(); |
| 641 | } |
| 642 | |
| 643 | return new ImageReaderIterator(iter); |
| 644 | } |
| 645 | |
| 646 | private static Method readerFormatNamesMethod; |
| 647 | private static Method readerFileSuffixesMethod; |
| 648 | private static Method readerMIMETypesMethod; |
| 649 | private static Method writerFormatNamesMethod; |
| 650 | private static Method writerFileSuffixesMethod; |
| 651 | private static Method writerMIMETypesMethod; |
| 652 | |
| 653 | static { |
| 654 | try { |
| 655 | readerFormatNamesMethod = |
| 656 | ImageReaderSpi.class.getMethod("getFormatNames"); |
| 657 | readerFileSuffixesMethod = |
| 658 | ImageReaderSpi.class.getMethod("getFileSuffixes"); |
| 659 | readerMIMETypesMethod = |
| 660 | ImageReaderSpi.class.getMethod("getMIMETypes"); |
| 661 | |
| 662 | writerFormatNamesMethod = |
| 663 | ImageWriterSpi.class.getMethod("getFormatNames"); |
| 664 | writerFileSuffixesMethod = |
| 665 | ImageWriterSpi.class.getMethod("getFileSuffixes"); |
| 666 | writerMIMETypesMethod = |
| 667 | ImageWriterSpi.class.getMethod("getMIMETypes"); |
| 668 | } catch (NoSuchMethodException e) { |
| 669 | e.printStackTrace(); |
| 670 | } |
| 671 | } |
| 672 | |
| 673 | /** |
| 674 | * Returns an <code>Iterator</code> containing all currently |
| 675 | * registered <code>ImageReader</code>s that claim to be able to |
| 676 | * decode the named format. |
| 677 | * |
| 678 | * @param formatName a <code>String</code> containing the informal |
| 679 | * name of a format (<i>e.g.</i>, "jpeg" or "tiff". |
| 680 | * |
| 681 | * @return an <code>Iterator</code> containing |
| 682 | * <code>ImageReader</code>s. |
| 683 | * |
| 684 | * @exception IllegalArgumentException if <code>formatName</code> |
| 685 | * is <code>null</code>. |
| 686 | * |
| 687 | * @see javax.imageio.spi.ImageReaderSpi#getFormatNames |
| 688 | */ |
| 689 | public static Iterator<ImageReader> |
| 690 | getImageReadersByFormatName(String formatName) |
| 691 | { |
| 692 | if (formatName == null) { |
| 693 | throw new IllegalArgumentException("formatName == null!"); |
| 694 | } |
| 695 | Iterator iter; |
| 696 | // Ensure category is present |
| 697 | try { |
| 698 | iter = theRegistry.getServiceProviders(ImageReaderSpi.class, |
| 699 | new ContainsFilter(readerFormatNamesMethod, |
| 700 | formatName), |
| 701 | true); |
| 702 | } catch (IllegalArgumentException e) { |
| 703 | return Collections.emptyIterator(); |
| 704 | } |
| 705 | return new ImageReaderIterator(iter); |
| 706 | } |
| 707 | |
| 708 | /** |
| 709 | * Returns an <code>Iterator</code> containing all currently |
| 710 | * registered <code>ImageReader</code>s that claim to be able to |
| 711 | * decode files with the given suffix. |
| 712 | * |
| 713 | * @param fileSuffix a <code>String</code> containing a file |
| 714 | * suffix (<i>e.g.</i>, "jpg" or "tiff"). |
| 715 | * |
| 716 | * @return an <code>Iterator</code> containing |
| 717 | * <code>ImageReader</code>s. |
| 718 | * |
| 719 | * @exception IllegalArgumentException if <code>fileSuffix</code> |
| 720 | * is <code>null</code>. |
| 721 | * |
| 722 | * @see javax.imageio.spi.ImageReaderSpi#getFileSuffixes |
| 723 | */ |
| 724 | public static Iterator<ImageReader> |
| 725 | getImageReadersBySuffix(String fileSuffix) |
| 726 | { |
| 727 | if (fileSuffix == null) { |
| 728 | throw new IllegalArgumentException("fileSuffix == null!"); |
| 729 | } |
| 730 | // Ensure category is present |
| 731 | Iterator iter; |
| 732 | try { |
| 733 | iter = theRegistry.getServiceProviders(ImageReaderSpi.class, |
| 734 | new ContainsFilter(readerFileSuffixesMethod, |
| 735 | fileSuffix), |
| 736 | true); |
| 737 | } catch (IllegalArgumentException e) { |
| 738 | return Collections.emptyIterator(); |
| 739 | } |
| 740 | return new ImageReaderIterator(iter); |
| 741 | } |
| 742 | |
| 743 | /** |
| 744 | * Returns an <code>Iterator</code> containing all currently |
| 745 | * registered <code>ImageReader</code>s that claim to be able to |
| 746 | * decode files with the given MIME type. |
| 747 | * |
| 748 | * @param MIMEType a <code>String</code> containing a file |
| 749 | * suffix (<i>e.g.</i>, "image/jpeg" or "image/x-bmp"). |
| 750 | * |
| 751 | * @return an <code>Iterator</code> containing |
| 752 | * <code>ImageReader</code>s. |
| 753 | * |
| 754 | * @exception IllegalArgumentException if <code>MIMEType</code> is |
| 755 | * <code>null</code>. |
| 756 | * |
| 757 | * @see javax.imageio.spi.ImageReaderSpi#getMIMETypes |
| 758 | */ |
| 759 | public static Iterator<ImageReader> |
| 760 | getImageReadersByMIMEType(String MIMEType) |
| 761 | { |
| 762 | if (MIMEType == null) { |
| 763 | throw new IllegalArgumentException("MIMEType == null!"); |
| 764 | } |
| 765 | // Ensure category is present |
| 766 | Iterator iter; |
| 767 | try { |
| 768 | iter = theRegistry.getServiceProviders(ImageReaderSpi.class, |
| 769 | new ContainsFilter(readerMIMETypesMethod, |
| 770 | MIMEType), |
| 771 | true); |
| 772 | } catch (IllegalArgumentException e) { |
| 773 | return Collections.emptyIterator(); |
| 774 | } |
| 775 | return new ImageReaderIterator(iter); |
| 776 | } |
| 777 | |
| 778 | // Writers |
| 779 | |
| 780 | /** |
| 781 | * Returns an array of <code>String</code>s listing all of the |
| 782 | * informal format names understood by the current set of registered |
| 783 | * writers. |
| 784 | * |
| 785 | * @return an array of <code>String</code>s. |
| 786 | */ |
| 787 | public static String[] getWriterFormatNames() { |
| 788 | return getReaderWriterInfo(ImageWriterSpi.class, |
| 789 | SpiInfo.FORMAT_NAMES); |
| 790 | } |
| 791 | |
| 792 | /** |
| 793 | * Returns an array of <code>String</code>s listing all of the |
| 794 | * MIME types understood by the current set of registered |
| 795 | * writers. |
| 796 | * |
| 797 | * @return an array of <code>String</code>s. |
| 798 | */ |
| 799 | public static String[] getWriterMIMETypes() { |
| 800 | return getReaderWriterInfo(ImageWriterSpi.class, |
| 801 | SpiInfo.MIME_TYPES); |
| 802 | } |
| 803 | |
| 804 | /** |
| 805 | * Returns an array of <code>String</code>s listing all of the |
| 806 | * file suffixes associated with the formats understood |
| 807 | * by the current set of registered writers. |
| 808 | * |
| 809 | * @return an array of <code>String</code>s. |
| 810 | * @since 1.6 |
| 811 | */ |
| 812 | public static String[] getWriterFileSuffixes() { |
| 813 | return getReaderWriterInfo(ImageWriterSpi.class, |
| 814 | SpiInfo.FILE_SUFFIXES); |
| 815 | } |
| 816 | |
| 817 | static class ImageWriterIterator implements Iterator<ImageWriter> { |
| 818 | // Contains ImageWriterSpis |
| 819 | public Iterator iter; |
| 820 | |
| 821 | public ImageWriterIterator(Iterator iter) { |
| 822 | this.iter = iter; |
| 823 | } |
| 824 | |
| 825 | public boolean hasNext() { |
| 826 | return iter.hasNext(); |
| 827 | } |
| 828 | |
| 829 | public ImageWriter next() { |
| 830 | ImageWriterSpi spi = null; |
| 831 | try { |
| 832 | spi = (ImageWriterSpi)iter.next(); |
| 833 | return spi.createWriterInstance(); |
| 834 | } catch (IOException e) { |
| 835 | // Deregister the spi in this case, but only as a writerSpi |
| 836 | theRegistry.deregisterServiceProvider(spi, ImageWriterSpi.class); |
| 837 | } |
| 838 | return null; |
| 839 | } |
| 840 | |
| 841 | public void remove() { |
| 842 | throw new UnsupportedOperationException(); |
| 843 | } |
| 844 | } |
| 845 | |
| 846 | private static boolean contains(String[] names, String name) { |
| 847 | for (int i = 0; i < names.length; i++) { |
| 848 | if (name.equalsIgnoreCase(names[i])) { |
| 849 | return true; |
| 850 | } |
| 851 | } |
| 852 | |
| 853 | return false; |
| 854 | } |
| 855 | |
| 856 | /** |
| 857 | * Returns an <code>Iterator</code> containing all currently |
| 858 | * registered <code>ImageWriter</code>s that claim to be able to |
| 859 | * encode the named format. |
| 860 | * |
| 861 | * @param formatName a <code>String</code> containing the informal |
| 862 | * name of a format (<i>e.g.</i>, "jpeg" or "tiff". |
| 863 | * |
| 864 | * @return an <code>Iterator</code> containing |
| 865 | * <code>ImageWriter</code>s. |
| 866 | * |
| 867 | * @exception IllegalArgumentException if <code>formatName</code> is |
| 868 | * <code>null</code>. |
| 869 | * |
| 870 | * @see javax.imageio.spi.ImageWriterSpi#getFormatNames |
| 871 | */ |
| 872 | public static Iterator<ImageWriter> |
| 873 | getImageWritersByFormatName(String formatName) |
| 874 | { |
| 875 | if (formatName == null) { |
| 876 | throw new IllegalArgumentException("formatName == null!"); |
| 877 | } |
| 878 | Iterator iter; |
| 879 | // Ensure category is present |
| 880 | try { |
| 881 | iter = theRegistry.getServiceProviders(ImageWriterSpi.class, |
| 882 | new ContainsFilter(writerFormatNamesMethod, |
| 883 | formatName), |
| 884 | true); |
| 885 | } catch (IllegalArgumentException e) { |
| 886 | return Collections.emptyIterator(); |
| 887 | } |
| 888 | return new ImageWriterIterator(iter); |
| 889 | } |
| 890 | |
| 891 | /** |
| 892 | * Returns an <code>Iterator</code> containing all currently |
| 893 | * registered <code>ImageWriter</code>s that claim to be able to |
| 894 | * encode files with the given suffix. |
| 895 | * |
| 896 | * @param fileSuffix a <code>String</code> containing a file |
| 897 | * suffix (<i>e.g.</i>, "jpg" or "tiff"). |
| 898 | * |
| 899 | * @return an <code>Iterator</code> containing <code>ImageWriter</code>s. |
| 900 | * |
| 901 | * @exception IllegalArgumentException if <code>fileSuffix</code> is |
| 902 | * <code>null</code>. |
| 903 | * |
| 904 | * @see javax.imageio.spi.ImageWriterSpi#getFileSuffixes |
| 905 | */ |
| 906 | public static Iterator<ImageWriter> |
| 907 | getImageWritersBySuffix(String fileSuffix) |
| 908 | { |
| 909 | if (fileSuffix == null) { |
| 910 | throw new IllegalArgumentException("fileSuffix == null!"); |
| 911 | } |
| 912 | Iterator iter; |
| 913 | // Ensure category is present |
| 914 | try { |
| 915 | iter = theRegistry.getServiceProviders(ImageWriterSpi.class, |
| 916 | new ContainsFilter(writerFileSuffixesMethod, |
| 917 | fileSuffix), |
| 918 | true); |
| 919 | } catch (IllegalArgumentException e) { |
| 920 | return Collections.emptyIterator(); |
| 921 | } |
| 922 | return new ImageWriterIterator(iter); |
| 923 | } |
| 924 | |
| 925 | /** |
| 926 | * Returns an <code>Iterator</code> containing all currently |
| 927 | * registered <code>ImageWriter</code>s that claim to be able to |
| 928 | * encode files with the given MIME type. |
| 929 | * |
| 930 | * @param MIMEType a <code>String</code> containing a file |
| 931 | * suffix (<i>e.g.</i>, "image/jpeg" or "image/x-bmp"). |
| 932 | * |
| 933 | * @return an <code>Iterator</code> containing <code>ImageWriter</code>s. |
| 934 | * |
| 935 | * @exception IllegalArgumentException if <code>MIMEType</code> is |
| 936 | * <code>null</code>. |
| 937 | * |
| 938 | * @see javax.imageio.spi.ImageWriterSpi#getMIMETypes |
| 939 | */ |
| 940 | public static Iterator<ImageWriter> |
| 941 | getImageWritersByMIMEType(String MIMEType) |
| 942 | { |
| 943 | if (MIMEType == null) { |
| 944 | throw new IllegalArgumentException("MIMEType == null!"); |
| 945 | } |
| 946 | Iterator iter; |
| 947 | // Ensure category is present |
| 948 | try { |
| 949 | iter = theRegistry.getServiceProviders(ImageWriterSpi.class, |
| 950 | new ContainsFilter(writerMIMETypesMethod, |
| 951 | MIMEType), |
| 952 | true); |
| 953 | } catch (IllegalArgumentException e) { |
| 954 | return Collections.emptyIterator(); |
| 955 | } |
| 956 | return new ImageWriterIterator(iter); |
| 957 | } |
| 958 | |
| 959 | /** |
| 960 | * Returns an <code>ImageWriter</code>corresponding to the given |
| 961 | * <code>ImageReader</code>, if there is one, or <code>null</code> |
| 962 | * if the plug-in for this <code>ImageReader</code> does not |
| 963 | * specify a corresponding <code>ImageWriter</code>, or if the |
| 964 | * given <code>ImageReader</code> is not registered. This |
| 965 | * mechanism may be used to obtain an <code>ImageWriter</code> |
| 966 | * that will understand the internal structure of non-pixel |
| 967 | * metadata (as encoded by <code>IIOMetadata</code> objects) |
| 968 | * generated by the <code>ImageReader</code>. By obtaining this |
| 969 | * data from the <code>ImageReader</code> and passing it on to the |
| 970 | * <code>ImageWriter</code> obtained with this method, a client |
| 971 | * program can read an image, modify it in some way, and write it |
| 972 | * back out preserving all metadata, without having to understand |
| 973 | * anything about the structure of the metadata, or even about |
| 974 | * the image format. Note that this method returns the |
| 975 | * "preferred" writer, which is the first in the list returned by |
| 976 | * <code>javax.imageio.spi.ImageReaderSpi.getImageWriterSpiNames()</code>. |
| 977 | * |
| 978 | * @param reader an instance of a registered <code>ImageReader</code>. |
| 979 | * |
| 980 | * @return an <code>ImageWriter</code>, or null. |
| 981 | * |
| 982 | * @exception IllegalArgumentException if <code>reader</code> is |
| 983 | * <code>null</code>. |
| 984 | * |
| 985 | * @see #getImageReader(ImageWriter) |
| 986 | * @see javax.imageio.spi.ImageReaderSpi#getImageWriterSpiNames() |
| 987 | */ |
| 988 | public static ImageWriter getImageWriter(ImageReader reader) { |
| 989 | if (reader == null) { |
| 990 | throw new IllegalArgumentException("reader == null!"); |
| 991 | } |
| 992 | |
| 993 | ImageReaderSpi readerSpi = reader.getOriginatingProvider(); |
| 994 | if (readerSpi == null) { |
| 995 | Iterator readerSpiIter; |
| 996 | // Ensure category is present |
| 997 | try { |
| 998 | readerSpiIter = |
| 999 | theRegistry.getServiceProviders(ImageReaderSpi.class, |
| 1000 | false); |
| 1001 | } catch (IllegalArgumentException e) { |
| 1002 | return null; |
| 1003 | } |
| 1004 | |
| 1005 | while (readerSpiIter.hasNext()) { |
| 1006 | ImageReaderSpi temp = (ImageReaderSpi) readerSpiIter.next(); |
| 1007 | if (temp.isOwnReader(reader)) { |
| 1008 | readerSpi = temp; |
| 1009 | break; |
| 1010 | } |
| 1011 | } |
| 1012 | if (readerSpi == null) { |
| 1013 | return null; |
| 1014 | } |
| 1015 | } |
| 1016 | |
| 1017 | String[] writerNames = readerSpi.getImageWriterSpiNames(); |
| 1018 | if (writerNames == null) { |
| 1019 | return null; |
| 1020 | } |
| 1021 | |
| 1022 | Class writerSpiClass = null; |
| 1023 | try { |
| 1024 | writerSpiClass = Class.forName(writerNames[0], true, |
| 1025 | ClassLoader.getSystemClassLoader()); |
| 1026 | } catch (ClassNotFoundException e) { |
| 1027 | return null; |
| 1028 | } |
| 1029 | |
| 1030 | ImageWriterSpi writerSpi = (ImageWriterSpi) |
| 1031 | theRegistry.getServiceProviderByClass(writerSpiClass); |
| 1032 | if (writerSpi == null) { |
| 1033 | return null; |
| 1034 | } |
| 1035 | |
| 1036 | try { |
| 1037 | return writerSpi.createWriterInstance(); |
| 1038 | } catch (IOException e) { |
| 1039 | // Deregister the spi in this case, but only as a writerSpi |
| 1040 | theRegistry.deregisterServiceProvider(writerSpi, |
| 1041 | ImageWriterSpi.class); |
| 1042 | return null; |
| 1043 | } |
| 1044 | } |
| 1045 | |
| 1046 | /** |
| 1047 | * Returns an <code>ImageReader</code>corresponding to the given |
| 1048 | * <code>ImageWriter</code>, if there is one, or <code>null</code> |
| 1049 | * if the plug-in for this <code>ImageWriter</code> does not |
| 1050 | * specify a corresponding <code>ImageReader</code>, or if the |
| 1051 | * given <code>ImageWriter</code> is not registered. This method |
| 1052 | * is provided principally for symmetry with |
| 1053 | * <code>getImageWriter(ImageReader)</code>. Note that this |
| 1054 | * method returns the "preferred" reader, which is the first in |
| 1055 | * the list returned by |
| 1056 | * javax.imageio.spi.ImageWriterSpi.<code>getImageReaderSpiNames()</code>. |
| 1057 | * |
| 1058 | * @param writer an instance of a registered <code>ImageWriter</code>. |
| 1059 | * |
| 1060 | * @return an <code>ImageReader</code>, or null. |
| 1061 | * |
| 1062 | * @exception IllegalArgumentException if <code>writer</code> is |
| 1063 | * <code>null</code>. |
| 1064 | * |
| 1065 | * @see #getImageWriter(ImageReader) |
| 1066 | * @see javax.imageio.spi.ImageWriterSpi#getImageReaderSpiNames() |
| 1067 | */ |
| 1068 | public static ImageReader getImageReader(ImageWriter writer) { |
| 1069 | if (writer == null) { |
| 1070 | throw new IllegalArgumentException("writer == null!"); |
| 1071 | } |
| 1072 | |
| 1073 | ImageWriterSpi writerSpi = writer.getOriginatingProvider(); |
| 1074 | if (writerSpi == null) { |
| 1075 | Iterator writerSpiIter; |
| 1076 | // Ensure category is present |
| 1077 | try { |
| 1078 | writerSpiIter = |
| 1079 | theRegistry.getServiceProviders(ImageWriterSpi.class, |
| 1080 | false); |
| 1081 | } catch (IllegalArgumentException e) { |
| 1082 | return null; |
| 1083 | } |
| 1084 | |
| 1085 | while (writerSpiIter.hasNext()) { |
| 1086 | ImageWriterSpi temp = (ImageWriterSpi) writerSpiIter.next(); |
| 1087 | if (temp.isOwnWriter(writer)) { |
| 1088 | writerSpi = temp; |
| 1089 | break; |
| 1090 | } |
| 1091 | } |
| 1092 | if (writerSpi == null) { |
| 1093 | return null; |
| 1094 | } |
| 1095 | } |
| 1096 | |
| 1097 | String[] readerNames = writerSpi.getImageReaderSpiNames(); |
| 1098 | if (readerNames == null) { |
| 1099 | return null; |
| 1100 | } |
| 1101 | |
| 1102 | Class readerSpiClass = null; |
| 1103 | try { |
| 1104 | readerSpiClass = Class.forName(readerNames[0], true, |
| 1105 | ClassLoader.getSystemClassLoader()); |
| 1106 | } catch (ClassNotFoundException e) { |
| 1107 | return null; |
| 1108 | } |
| 1109 | |
| 1110 | ImageReaderSpi readerSpi = (ImageReaderSpi) |
| 1111 | theRegistry.getServiceProviderByClass(readerSpiClass); |
| 1112 | if (readerSpi == null) { |
| 1113 | return null; |
| 1114 | } |
| 1115 | |
| 1116 | try { |
| 1117 | return readerSpi.createReaderInstance(); |
| 1118 | } catch (IOException e) { |
| 1119 | // Deregister the spi in this case, but only as a readerSpi |
| 1120 | theRegistry.deregisterServiceProvider(readerSpi, |
| 1121 | ImageReaderSpi.class); |
| 1122 | return null; |
| 1123 | } |
| 1124 | } |
| 1125 | |
| 1126 | /** |
| 1127 | * Returns an <code>Iterator</code> containing all currently |
| 1128 | * registered <code>ImageWriter</code>s that claim to be able to |
| 1129 | * encode images of the given layout (specified using an |
| 1130 | * <code>ImageTypeSpecifier</code>) in the given format. |
| 1131 | * |
| 1132 | * @param type an <code>ImageTypeSpecifier</code> indicating the |
| 1133 | * layout of the image to be written. |
| 1134 | * @param formatName the informal name of the <code>format</code>. |
| 1135 | * |
| 1136 | * @return an <code>Iterator</code> containing <code>ImageWriter</code>s. |
| 1137 | * |
| 1138 | * @exception IllegalArgumentException if any parameter is |
| 1139 | * <code>null</code>. |
| 1140 | * |
| 1141 | * @see javax.imageio.spi.ImageWriterSpi#canEncodeImage(ImageTypeSpecifier) |
| 1142 | */ |
| 1143 | public static Iterator<ImageWriter> |
| 1144 | getImageWriters(ImageTypeSpecifier type, String formatName) |
| 1145 | { |
| 1146 | if (type == null) { |
| 1147 | throw new IllegalArgumentException("type == null!"); |
| 1148 | } |
| 1149 | if (formatName == null) { |
| 1150 | throw new IllegalArgumentException("formatName == null!"); |
| 1151 | } |
| 1152 | |
| 1153 | Iterator iter; |
| 1154 | // Ensure category is present |
| 1155 | try { |
| 1156 | iter = theRegistry.getServiceProviders(ImageWriterSpi.class, |
| 1157 | new CanEncodeImageAndFormatFilter(type, |
| 1158 | formatName), |
| 1159 | true); |
| 1160 | } catch (IllegalArgumentException e) { |
| 1161 | return Collections.emptyIterator(); |
| 1162 | } |
| 1163 | |
| 1164 | return new ImageWriterIterator(iter); |
| 1165 | } |
| 1166 | |
| 1167 | static class ImageTranscoderIterator |
| 1168 | implements Iterator<ImageTranscoder> |
| 1169 | { |
| 1170 | // Contains ImageTranscoderSpis |
| 1171 | public Iterator iter; |
| 1172 | |
| 1173 | public ImageTranscoderIterator(Iterator iter) { |
| 1174 | this.iter = iter; |
| 1175 | } |
| 1176 | |
| 1177 | public boolean hasNext() { |
| 1178 | return iter.hasNext(); |
| 1179 | } |
| 1180 | |
| 1181 | public ImageTranscoder next() { |
| 1182 | ImageTranscoderSpi spi = null; |
| 1183 | spi = (ImageTranscoderSpi)iter.next(); |
| 1184 | return spi.createTranscoderInstance(); |
| 1185 | } |
| 1186 | |
| 1187 | public void remove() { |
| 1188 | throw new UnsupportedOperationException(); |
| 1189 | } |
| 1190 | } |
| 1191 | |
| 1192 | static class TranscoderFilter |
| 1193 | implements ServiceRegistry.Filter { |
| 1194 | |
| 1195 | String readerSpiName; |
| 1196 | String writerSpiName; |
| 1197 | |
| 1198 | public TranscoderFilter(ImageReaderSpi readerSpi, |
| 1199 | ImageWriterSpi writerSpi) { |
| 1200 | this.readerSpiName = readerSpi.getClass().getName(); |
| 1201 | this.writerSpiName = writerSpi.getClass().getName(); |
| 1202 | } |
| 1203 | |
| 1204 | public boolean filter(Object elt) { |
| 1205 | ImageTranscoderSpi spi = (ImageTranscoderSpi)elt; |
| 1206 | String readerName = spi.getReaderServiceProviderName(); |
| 1207 | String writerName = spi.getWriterServiceProviderName(); |
| 1208 | return (readerName.equals(readerSpiName) && |
| 1209 | writerName.equals(writerSpiName)); |
| 1210 | } |
| 1211 | } |
| 1212 | |
| 1213 | /** |
| 1214 | * Returns an <code>Iterator</code> containing all currently |
| 1215 | * registered <code>ImageTranscoder</code>s that claim to be |
| 1216 | * able to transcode between the metadata of the given |
| 1217 | * <code>ImageReader</code> and <code>ImageWriter</code>. |
| 1218 | * |
| 1219 | * @param reader an <code>ImageReader</code>. |
| 1220 | * @param writer an <code>ImageWriter</code>. |
| 1221 | * |
| 1222 | * @return an <code>Iterator</code> containing |
| 1223 | * <code>ImageTranscoder</code>s. |
| 1224 | * |
| 1225 | * @exception IllegalArgumentException if <code>reader</code> or |
| 1226 | * <code>writer</code> is <code>null</code>. |
| 1227 | */ |
| 1228 | public static Iterator<ImageTranscoder> |
| 1229 | getImageTranscoders(ImageReader reader, ImageWriter writer) |
| 1230 | { |
| 1231 | if (reader == null) { |
| 1232 | throw new IllegalArgumentException("reader == null!"); |
| 1233 | } |
| 1234 | if (writer == null) { |
| 1235 | throw new IllegalArgumentException("writer == null!"); |
| 1236 | } |
| 1237 | ImageReaderSpi readerSpi = reader.getOriginatingProvider(); |
| 1238 | ImageWriterSpi writerSpi = writer.getOriginatingProvider(); |
| 1239 | ServiceRegistry.Filter filter = |
| 1240 | new TranscoderFilter(readerSpi, writerSpi); |
| 1241 | |
| 1242 | Iterator iter; |
| 1243 | // Ensure category is present |
| 1244 | try { |
| 1245 | iter = theRegistry.getServiceProviders(ImageTranscoderSpi.class, |
| 1246 | filter, true); |
| 1247 | } catch (IllegalArgumentException e) { |
| 1248 | return Collections.emptyIterator(); |
| 1249 | } |
| 1250 | return new ImageTranscoderIterator(iter); |
| 1251 | } |
| 1252 | |
| 1253 | // All-in-one methods |
| 1254 | |
| 1255 | /** |
| 1256 | * Returns a <code>BufferedImage</code> as the result of decoding |
| 1257 | * a supplied <code>File</code> with an <code>ImageReader</code> |
| 1258 | * chosen automatically from among those currently registered. |
| 1259 | * The <code>File</code> is wrapped in an |
| 1260 | * <code>ImageInputStream</code>. If no registered |
| 1261 | * <code>ImageReader</code> claims to be able to read the |
| 1262 | * resulting stream, <code>null</code> is returned. |
| 1263 | * |
| 1264 | * <p> The current cache settings from <code>getUseCache</code>and |
| 1265 | * <code>getCacheDirectory</code> will be used to control caching in the |
| 1266 | * <code>ImageInputStream</code> that is created. |
| 1267 | * |
| 1268 | * <p> Note that there is no <code>read</code> method that takes a |
| 1269 | * filename as a <code>String</code>; use this method instead after |
| 1270 | * creating a <code>File</code> from the filename. |
| 1271 | * |
| 1272 | * <p> This method does not attempt to locate |
| 1273 | * <code>ImageReader</code>s that can read directly from a |
| 1274 | * <code>File</code>; that may be accomplished using |
| 1275 | * <code>IIORegistry</code> and <code>ImageReaderSpi</code>. |
| 1276 | * |
| 1277 | * @param input a <code>File</code> to read from. |
| 1278 | * |
| 1279 | * @return a <code>BufferedImage</code> containing the decoded |
| 1280 | * contents of the input, or <code>null</code>. |
| 1281 | * |
| 1282 | * @exception IllegalArgumentException if <code>input</code> is |
| 1283 | * <code>null</code>. |
| 1284 | * @exception IOException if an error occurs during reading. |
| 1285 | */ |
| 1286 | public static BufferedImage read(File input) throws IOException { |
| 1287 | if (input == null) { |
| 1288 | throw new IllegalArgumentException("input == null!"); |
| 1289 | } |
| 1290 | if (!input.canRead()) { |
| 1291 | throw new IIOException("Can't read input file!"); |
| 1292 | } |
| 1293 | |
| 1294 | ImageInputStream stream = createImageInputStream(input); |
| 1295 | if (stream == null) { |
| 1296 | throw new IIOException("Can't create an ImageInputStream!"); |
| 1297 | } |
| 1298 | BufferedImage bi = read(stream); |
| 1299 | if (bi == null) { |
| 1300 | stream.close(); |
| 1301 | } |
| 1302 | return bi; |
| 1303 | } |
| 1304 | |
| 1305 | /** |
| 1306 | * Returns a <code>BufferedImage</code> as the result of decoding |
| 1307 | * a supplied <code>InputStream</code> with an <code>ImageReader</code> |
| 1308 | * chosen automatically from among those currently registered. |
| 1309 | * The <code>InputStream</code> is wrapped in an |
| 1310 | * <code>ImageInputStream</code>. If no registered |
| 1311 | * <code>ImageReader</code> claims to be able to read the |
| 1312 | * resulting stream, <code>null</code> is returned. |
| 1313 | * |
| 1314 | * <p> The current cache settings from <code>getUseCache</code>and |
| 1315 | * <code>getCacheDirectory</code> will be used to control caching in the |
| 1316 | * <code>ImageInputStream</code> that is created. |
| 1317 | * |
| 1318 | * <p> This method does not attempt to locate |
| 1319 | * <code>ImageReader</code>s that can read directly from an |
| 1320 | * <code>InputStream</code>; that may be accomplished using |
| 1321 | * <code>IIORegistry</code> and <code>ImageReaderSpi</code>. |
| 1322 | * |
| 1323 | * <p> This method <em>does not</em> close the provided |
| 1324 | * <code>InputStream</code> after the read operation has completed; |
| 1325 | * it is the responsibility of the caller to close the stream, if desired. |
| 1326 | * |
| 1327 | * @param input an <code>InputStream</code> to read from. |
| 1328 | * |
| 1329 | * @return a <code>BufferedImage</code> containing the decoded |
| 1330 | * contents of the input, or <code>null</code>. |
| 1331 | * |
| 1332 | * @exception IllegalArgumentException if <code>input</code> is |
| 1333 | * <code>null</code>. |
| 1334 | * @exception IOException if an error occurs during reading. |
| 1335 | */ |
| 1336 | public static BufferedImage read(InputStream input) throws IOException { |
| 1337 | if (input == null) { |
| 1338 | throw new IllegalArgumentException("input == null!"); |
| 1339 | } |
| 1340 | |
| 1341 | ImageInputStream stream = createImageInputStream(input); |
| 1342 | BufferedImage bi = read(stream); |
| 1343 | if (bi == null) { |
| 1344 | stream.close(); |
| 1345 | } |
| 1346 | return bi; |
| 1347 | } |
| 1348 | |
| 1349 | /** |
| 1350 | * Returns a <code>BufferedImage</code> as the result of decoding |
| 1351 | * a supplied <code>URL</code> with an <code>ImageReader</code> |
| 1352 | * chosen automatically from among those currently registered. An |
| 1353 | * <code>InputStream</code> is obtained from the <code>URL</code>, |
| 1354 | * which is wrapped in an <code>ImageInputStream</code>. If no |
| 1355 | * registered <code>ImageReader</code> claims to be able to read |
| 1356 | * the resulting stream, <code>null</code> is returned. |
| 1357 | * |
| 1358 | * <p> The current cache settings from <code>getUseCache</code>and |
| 1359 | * <code>getCacheDirectory</code> will be used to control caching in the |
| 1360 | * <code>ImageInputStream</code> that is created. |
| 1361 | * |
| 1362 | * <p> This method does not attempt to locate |
| 1363 | * <code>ImageReader</code>s that can read directly from a |
| 1364 | * <code>URL</code>; that may be accomplished using |
| 1365 | * <code>IIORegistry</code> and <code>ImageReaderSpi</code>. |
| 1366 | * |
| 1367 | * @param input a <code>URL</code> to read from. |
| 1368 | * |
| 1369 | * @return a <code>BufferedImage</code> containing the decoded |
| 1370 | * contents of the input, or <code>null</code>. |
| 1371 | * |
| 1372 | * @exception IllegalArgumentException if <code>input</code> is |
| 1373 | * <code>null</code>. |
| 1374 | * @exception IOException if an error occurs during reading. |
| 1375 | */ |
| 1376 | public static BufferedImage read(URL input) throws IOException { |
| 1377 | if (input == null) { |
| 1378 | throw new IllegalArgumentException("input == null!"); |
| 1379 | } |
| 1380 | |
| 1381 | InputStream istream = null; |
| 1382 | try { |
| 1383 | istream = input.openStream(); |
| 1384 | } catch (IOException e) { |
| 1385 | throw new IIOException("Can't get input stream from URL!", e); |
| 1386 | } |
| 1387 | ImageInputStream stream = createImageInputStream(istream); |
| 1388 | BufferedImage bi; |
| 1389 | try { |
| 1390 | bi = read(stream); |
| 1391 | if (bi == null) { |
| 1392 | stream.close(); |
| 1393 | } |
| 1394 | } finally { |
| 1395 | istream.close(); |
| 1396 | } |
| 1397 | return bi; |
| 1398 | } |
| 1399 | |
| 1400 | /** |
| 1401 | * Returns a <code>BufferedImage</code> as the result of decoding |
| 1402 | * a supplied <code>ImageInputStream</code> with an |
| 1403 | * <code>ImageReader</code> chosen automatically from among those |
| 1404 | * currently registered. If no registered |
| 1405 | * <code>ImageReader</code> claims to be able to read the stream, |
| 1406 | * <code>null</code> is returned. |
| 1407 | * |
| 1408 | * <p> Unlike most other methods in this class, this method <em>does</em> |
| 1409 | * close the provided <code>ImageInputStream</code> after the read |
| 1410 | * operation has completed, unless <code>null</code> is returned, |
| 1411 | * in which case this method <em>does not</em> close the stream. |
| 1412 | * |
| 1413 | * @param stream an <code>ImageInputStream</code> to read from. |
| 1414 | * |
| 1415 | * @return a <code>BufferedImage</code> containing the decoded |
| 1416 | * contents of the input, or <code>null</code>. |
| 1417 | * |
| 1418 | * @exception IllegalArgumentException if <code>stream</code> is |
| 1419 | * <code>null</code>. |
| 1420 | * @exception IOException if an error occurs during reading. |
| 1421 | */ |
| 1422 | public static BufferedImage read(ImageInputStream stream) |
| 1423 | throws IOException { |
| 1424 | if (stream == null) { |
| 1425 | throw new IllegalArgumentException("stream == null!"); |
| 1426 | } |
| 1427 | |
| 1428 | Iterator iter = getImageReaders(stream); |
| 1429 | if (!iter.hasNext()) { |
| 1430 | return null; |
| 1431 | } |
| 1432 | |
| 1433 | ImageReader reader = (ImageReader)iter.next(); |
| 1434 | ImageReadParam param = reader.getDefaultReadParam(); |
| 1435 | reader.setInput(stream, true, true); |
| 1436 | BufferedImage bi; |
| 1437 | try { |
| 1438 | bi = reader.read(0, param); |
| 1439 | } finally { |
| 1440 | reader.dispose(); |
| 1441 | stream.close(); |
| 1442 | } |
| 1443 | return bi; |
| 1444 | } |
| 1445 | |
| 1446 | /** |
| 1447 | * Writes an image using the an arbitrary <code>ImageWriter</code> |
| 1448 | * that supports the given format to an |
| 1449 | * <code>ImageOutputStream</code>. The image is written to the |
| 1450 | * <code>ImageOutputStream</code> starting at the current stream |
| 1451 | * pointer, overwriting existing stream data from that point |
| 1452 | * forward, if present. |
| 1453 | * |
| 1454 | * <p> This method <em>does not</em> close the provided |
| 1455 | * <code>ImageOutputStream</code> after the write operation has completed; |
| 1456 | * it is the responsibility of the caller to close the stream, if desired. |
| 1457 | * |
| 1458 | * @param im a <code>RenderedImage</code> to be written. |
| 1459 | * @param formatName a <code>String</code> containg the informal |
| 1460 | * name of the format. |
| 1461 | * @param output an <code>ImageOutputStream</code> to be written to. |
| 1462 | * |
| 1463 | * @return <code>false</code> if no appropriate writer is found. |
| 1464 | * |
| 1465 | * @exception IllegalArgumentException if any parameter is |
| 1466 | * <code>null</code>. |
| 1467 | * @exception IOException if an error occurs during writing. |
| 1468 | */ |
| 1469 | public static boolean write(RenderedImage im, |
| 1470 | String formatName, |
| 1471 | ImageOutputStream output) throws IOException { |
| 1472 | if (im == null) { |
| 1473 | throw new IllegalArgumentException("im == null!"); |
| 1474 | } |
| 1475 | if (formatName == null) { |
| 1476 | throw new IllegalArgumentException("formatName == null!"); |
| 1477 | } |
| 1478 | if (output == null) { |
| 1479 | throw new IllegalArgumentException("output == null!"); |
| 1480 | } |
| 1481 | |
| 1482 | return doWrite(im, getWriter(im, formatName), output); |
| 1483 | } |
| 1484 | |
| 1485 | /** |
| 1486 | * Writes an image using an arbitrary <code>ImageWriter</code> |
| 1487 | * that supports the given format to a <code>File</code>. If |
| 1488 | * there is already a <code>File</code> present, its contents are |
| 1489 | * discarded. |
| 1490 | * |
| 1491 | * @param im a <code>RenderedImage</code> to be written. |
| 1492 | * @param formatName a <code>String</code> containg the informal |
| 1493 | * name of the format. |
| 1494 | * @param output a <code>File</code> to be written to. |
| 1495 | * |
| 1496 | * @return <code>false</code> if no appropriate writer is found. |
| 1497 | * |
| 1498 | * @exception IllegalArgumentException if any parameter is |
| 1499 | * <code>null</code>. |
| 1500 | * @exception IOException if an error occurs during writing. |
| 1501 | */ |
| 1502 | public static boolean write(RenderedImage im, |
| 1503 | String formatName, |
| 1504 | File output) throws IOException { |
| 1505 | if (output == null) { |
| 1506 | throw new IllegalArgumentException("output == null!"); |
| 1507 | } |
| 1508 | ImageOutputStream stream = null; |
| 1509 | |
| 1510 | ImageWriter writer = getWriter(im, formatName); |
| 1511 | if (writer == null) { |
| 1512 | /* Do not make changes in the file system if we have |
| 1513 | * no appropriate writer. |
| 1514 | */ |
| 1515 | return false; |
| 1516 | } |
| 1517 | |
| 1518 | try { |
| 1519 | output.delete(); |
| 1520 | stream = createImageOutputStream(output); |
| 1521 | } catch (IOException e) { |
| 1522 | throw new IIOException("Can't create output stream!", e); |
| 1523 | } |
| 1524 | |
| 1525 | try { |
| 1526 | return doWrite(im, writer, stream); |
| 1527 | } finally { |
| 1528 | stream.close(); |
| 1529 | } |
| 1530 | } |
| 1531 | |
| 1532 | /** |
| 1533 | * Writes an image using an arbitrary <code>ImageWriter</code> |
| 1534 | * that supports the given format to an <code>OutputStream</code>. |
| 1535 | * |
| 1536 | * <p> This method <em>does not</em> close the provided |
| 1537 | * <code>OutputStream</code> after the write operation has completed; |
| 1538 | * it is the responsibility of the caller to close the stream, if desired. |
| 1539 | * |
| 1540 | * <p> The current cache settings from <code>getUseCache</code>and |
| 1541 | * <code>getCacheDirectory</code> will be used to control caching. |
| 1542 | * |
| 1543 | * @param im a <code>RenderedImage</code> to be written. |
| 1544 | * @param formatName a <code>String</code> containg the informal |
| 1545 | * name of the format. |
| 1546 | * @param output an <code>OutputStream</code> to be written to. |
| 1547 | * |
| 1548 | * @return <code>false</code> if no appropriate writer is found. |
| 1549 | * |
| 1550 | * @exception IllegalArgumentException if any parameter is |
| 1551 | * <code>null</code>. |
| 1552 | * @exception IOException if an error occurs during writing. |
| 1553 | */ |
| 1554 | public static boolean write(RenderedImage im, |
| 1555 | String formatName, |
| 1556 | OutputStream output) throws IOException { |
| 1557 | if (output == null) { |
| 1558 | throw new IllegalArgumentException("output == null!"); |
| 1559 | } |
| 1560 | ImageOutputStream stream = null; |
| 1561 | try { |
| 1562 | stream = createImageOutputStream(output); |
| 1563 | } catch (IOException e) { |
| 1564 | throw new IIOException("Can't create output stream!", e); |
| 1565 | } |
| 1566 | |
| 1567 | try { |
| 1568 | return doWrite(im, getWriter(im, formatName), stream); |
| 1569 | } finally { |
| 1570 | stream.close(); |
| 1571 | } |
| 1572 | } |
| 1573 | |
| 1574 | /** |
| 1575 | * Returns <code>ImageWriter</code> instance according to given |
| 1576 | * rendered image and image format or <code>null</code> if there |
| 1577 | * is no appropriate writer. |
| 1578 | */ |
| 1579 | private static ImageWriter getWriter(RenderedImage im, |
| 1580 | String formatName) { |
| 1581 | ImageTypeSpecifier type = |
| 1582 | ImageTypeSpecifier.createFromRenderedImage(im); |
| 1583 | Iterator<ImageWriter> iter = getImageWriters(type, formatName); |
| 1584 | |
| 1585 | if (iter.hasNext()) { |
| 1586 | return iter.next(); |
| 1587 | } else { |
| 1588 | return null; |
| 1589 | } |
| 1590 | } |
| 1591 | |
| 1592 | /** |
| 1593 | * Writes image to output stream using given image writer. |
| 1594 | */ |
| 1595 | private static boolean doWrite(RenderedImage im, ImageWriter writer, |
| 1596 | ImageOutputStream output) throws IOException { |
| 1597 | if (writer == null) { |
| 1598 | return false; |
| 1599 | } |
| 1600 | writer.setOutput(output); |
| 1601 | try { |
| 1602 | writer.write(im); |
| 1603 | } finally { |
| 1604 | writer.dispose(); |
| 1605 | output.flush(); |
| 1606 | } |
| 1607 | return true; |
| 1608 | } |
| 1609 | } |