1 /*
2 * Copyright (c) 1996, 2012, Oracle and/or its affiliates. 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /*
27 * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
28 * (C) Copyright IBM Corp. 1996 - 1999 - All Rights Reserved
29 *
30 * The original version of this source code and documentation
31 * is copyrighted and owned by Taligent, Inc., a wholly-owned
32 * subsidiary of IBM. These materials are provided under terms
33 * of a License Agreement between Taligent and Sun. This technology
34 * is protected by multiple US and International patents.
35 *
36 * This notice and attribution to Taligent may not be removed.
37 * Taligent is a registered trademark of Taligent, Inc.
38 *
39 */
40
41 package java.util;
42
43 import java.io.IOException;
44 import java.io.InputStream;
45 import java.lang.ref.ReferenceQueue;
46 import java.lang.ref.SoftReference;
47 import java.lang.ref.WeakReference;
48 import java.net.JarURLConnection;
49 import java.net.URL;
50 import java.net.URLConnection;
51 import java.security.AccessController;
52 import java.security.PrivilegedAction;
53 import java.security.PrivilegedActionException;
54 import java.security.PrivilegedExceptionAction;
55 import java.util.concurrent.ConcurrentHashMap;
56 import java.util.concurrent.ConcurrentMap;
57 import java.util.jar.JarEntry;
58 import java.util.spi.ResourceBundleControlProvider;
59
60 import sun.reflect.CallerSensitive;
61 import sun.reflect.Reflection;
62 import sun.util.locale.BaseLocale;
63 import sun.util.locale.LocaleObjectCache;
64
65
66 /**
67 *
68 * Resource bundles contain locale-specific objects. When your program needs a
69 * locale-specific resource, a <code>String</code> for example, your program can
70 * load it from the resource bundle that is appropriate for the current user's
71 * locale. In this way, you can write program code that is largely independent
72 * of the user's locale isolating most, if not all, of the locale-specific
73 * information in resource bundles.
74 *
75 * <p>
76 * This allows you to write programs that can:
77 * <UL type=SQUARE>
78 * <LI> be easily localized, or translated, into different languages
79 * <LI> handle multiple locales at once
80 * <LI> be easily modified later to support even more locales
81 * </UL>
82 *
83 * <P>
84 * Resource bundles belong to families whose members share a common base
85 * name, but whose names also have additional components that identify
86 * their locales. For example, the base name of a family of resource
87 * bundles might be "MyResources". The family should have a default
88 * resource bundle which simply has the same name as its family -
89 * "MyResources" - and will be used as the bundle of last resort if a
90 * specific locale is not supported. The family can then provide as
91 * many locale-specific members as needed, for example a German one
92 * named "MyResources_de".
93 *
94 * <P>
95 * Each resource bundle in a family contains the same items, but the items have
96 * been translated for the locale represented by that resource bundle.
97 * For example, both "MyResources" and "MyResources_de" may have a
98 * <code>String</code> that's used on a button for canceling operations.
99 * In "MyResources" the <code>String</code> may contain "Cancel" and in
100 * "MyResources_de" it may contain "Abbrechen".
101 *
102 * <P>
103 * If there are different resources for different countries, you
104 * can make specializations: for example, "MyResources_de_CH" contains objects for
105 * the German language (de) in Switzerland (CH). If you want to only
106 * modify some of the resources
107 * in the specialization, you can do so.
108 *
109 * <P>
110 * When your program needs a locale-specific object, it loads
111 * the <code>ResourceBundle</code> class using the
112 * {@link #getBundle(java.lang.String, java.util.Locale) getBundle}
113 * method:
114 * <blockquote>
115 * <pre>
116 * ResourceBundle myResources =
117 * ResourceBundle.getBundle("MyResources", currentLocale);
118 * </pre>
119 * </blockquote>
120 *
121 * <P>
122 * Resource bundles contain key/value pairs. The keys uniquely
123 * identify a locale-specific object in the bundle. Here's an
124 * example of a <code>ListResourceBundle</code> that contains
125 * two key/value pairs:
126 * <blockquote>
127 * <pre>
128 * public class MyResources extends ListResourceBundle {
129 * protected Object[][] getContents() {
130 * return new Object[][] {
131 * // LOCALIZE THE SECOND STRING OF EACH ARRAY (e.g., "OK")
132 * {"OkKey", "OK"},
133 * {"CancelKey", "Cancel"},
134 * // END OF MATERIAL TO LOCALIZE
135 * };
136 * }
137 * }
138 * </pre>
139 * </blockquote>
140 * Keys are always <code>String</code>s.
141 * In this example, the keys are "OkKey" and "CancelKey".
142 * In the above example, the values
143 * are also <code>String</code>s--"OK" and "Cancel"--but
144 * they don't have to be. The values can be any type of object.
145 *
146 * <P>
147 * You retrieve an object from resource bundle using the appropriate
148 * getter method. Because "OkKey" and "CancelKey"
149 * are both strings, you would use <code>getString</code> to retrieve them:
150 * <blockquote>
151 * <pre>
152 * button1 = new Button(myResources.getString("OkKey"));
153 * button2 = new Button(myResources.getString("CancelKey"));
154 * </pre>
155 * </blockquote>
156 * The getter methods all require the key as an argument and return
157 * the object if found. If the object is not found, the getter method
158 * throws a <code>MissingResourceException</code>.
159 *
160 * <P>
161 * Besides <code>getString</code>, <code>ResourceBundle</code> also provides
162 * a method for getting string arrays, <code>getStringArray</code>,
163 * as well as a generic <code>getObject</code> method for any other
164 * type of object. When using <code>getObject</code>, you'll
165 * have to cast the result to the appropriate type. For example:
166 * <blockquote>
167 * <pre>
168 * int[] myIntegers = (int[]) myResources.getObject("intList");
169 * </pre>
170 * </blockquote>
171 *
172 * <P>
173 * The Java Platform provides two subclasses of <code>ResourceBundle</code>,
174 * <code>ListResourceBundle</code> and <code>PropertyResourceBundle</code>,
175 * that provide a fairly simple way to create resources.
176 * As you saw briefly in a previous example, <code>ListResourceBundle</code>
177 * manages its resource as a list of key/value pairs.
178 * <code>PropertyResourceBundle</code> uses a properties file to manage
179 * its resources.
180 *
181 * <p>
182 * If <code>ListResourceBundle</code> or <code>PropertyResourceBundle</code>
183 * do not suit your needs, you can write your own <code>ResourceBundle</code>
184 * subclass. Your subclasses must override two methods: <code>handleGetObject</code>
185 * and <code>getKeys()</code>.
186 *
187 * <h4>ResourceBundle.Control</h4>
188 *
189 * The {@link ResourceBundle.Control} class provides information necessary
190 * to perform the bundle loading process by the <code>getBundle</code>
191 * factory methods that take a <code>ResourceBundle.Control</code>
192 * instance. You can implement your own subclass in order to enable
193 * non-standard resource bundle formats, change the search strategy, or
194 * define caching parameters. Refer to the descriptions of the class and the
195 * {@link #getBundle(String, Locale, ClassLoader, Control) getBundle}
196 * factory method for details.
197 *
198 * <p><a name="modify_default_behavior">For the {@code getBundle} factory
199 * methods that take no {@link Control} instance, their <a
200 * href="#default_behavior"> default behavior</a> of resource bundle loading
201 * can be modified with <em>installed</em> {@link
202 * ResourceBundleControlProvider} implementations. Any installed providers are
203 * detected at the {@code ResourceBundle} class loading time. If any of the
204 * providers provides a {@link Control} for the given base name, that {@link
205 * Control} will be used instead of the default {@link Control}. If there is
206 * more than one service provider installed for supporting the same base name,
207 * the first one returned from {@link ServiceLoader} will be used.
208 *
209 * <h4>Cache Management</h4>
210 *
211 * Resource bundle instances created by the <code>getBundle</code> factory
212 * methods are cached by default, and the factory methods return the same
213 * resource bundle instance multiple times if it has been
214 * cached. <code>getBundle</code> clients may clear the cache, manage the
215 * lifetime of cached resource bundle instances using time-to-live values,
216 * or specify not to cache resource bundle instances. Refer to the
217 * descriptions of the {@linkplain #getBundle(String, Locale, ClassLoader,
218 * Control) <code>getBundle</code> factory method}, {@link
219 * #clearCache(ClassLoader) clearCache}, {@link
220 * Control#getTimeToLive(String, Locale)
221 * ResourceBundle.Control.getTimeToLive}, and {@link
222 * Control#needsReload(String, Locale, String, ClassLoader, ResourceBundle,
223 * long) ResourceBundle.Control.needsReload} for details.
224 *
225 * <h4>Example</h4>
226 *
227 * The following is a very simple example of a <code>ResourceBundle</code>
228 * subclass, <code>MyResources</code>, that manages two resources (for a larger number of
229 * resources you would probably use a <code>Map</code>).
230 * Notice that you don't need to supply a value if
231 * a "parent-level" <code>ResourceBundle</code> handles the same
232 * key with the same value (as for the okKey below).
233 * <blockquote>
234 * <pre>
235 * // default (English language, United States)
236 * public class MyResources extends ResourceBundle {
237 * public Object handleGetObject(String key) {
238 * if (key.equals("okKey")) return "Ok";
239 * if (key.equals("cancelKey")) return "Cancel";
240 * return null;
241 * }
242 *
243 * public Enumeration<String> getKeys() {
244 * return Collections.enumeration(keySet());
245 * }
246 *
247 * // Overrides handleKeySet() so that the getKeys() implementation
248 * // can rely on the keySet() value.
249 * protected Set<String> handleKeySet() {
250 * return new HashSet<String>(Arrays.asList("okKey", "cancelKey"));
251 * }
252 * }
253 *
254 * // German language
255 * public class MyResources_de extends MyResources {
256 * public Object handleGetObject(String key) {
257 * // don't need okKey, since parent level handles it.
258 * if (key.equals("cancelKey")) return "Abbrechen";
259 * return null;
260 * }
261 *
262 * protected Set<String> handleKeySet() {
263 * return new HashSet<String>(Arrays.asList("cancelKey"));
264 * }
265 * }
266 * </pre>
267 * </blockquote>
268 * You do not have to restrict yourself to using a single family of
269 * <code>ResourceBundle</code>s. For example, you could have a set of bundles for
270 * exception messages, <code>ExceptionResources</code>
271 * (<code>ExceptionResources_fr</code>, <code>ExceptionResources_de</code>, ...),
272 * and one for widgets, <code>WidgetResource</code> (<code>WidgetResources_fr</code>,
273 * <code>WidgetResources_de</code>, ...); breaking up the resources however you like.
274 *
275 * @see ListResourceBundle
276 * @see PropertyResourceBundle
277 * @see MissingResourceException
278 * @since JDK1.1
279 */
280 public abstract class ResourceBundle {
281
282 /** initial size of the bundle cache */
283 private static final int INITIAL_CACHE_SIZE = 32;
284
285 /** constant indicating that no resource bundle exists */
286 private static final ResourceBundle NONEXISTENT_BUNDLE = new ResourceBundle() {
287 public Enumeration<String> getKeys() { return null; }
288 protected Object handleGetObject(String key) { return null; }
289 public String toString() { return "NONEXISTENT_BUNDLE"; }
290 };
291
292
293 /**
294 * The cache is a map from cache keys (with bundle base name, locale, and
295 * class loader) to either a resource bundle or NONEXISTENT_BUNDLE wrapped by a
296 * BundleReference.
297 *
298 * The cache is a ConcurrentMap, allowing the cache to be searched
299 * concurrently by multiple threads. This will also allow the cache keys
300 * to be reclaimed along with the ClassLoaders they reference.
301 *
302 * This variable would be better named "cache", but we keep the old
303 * name for compatibility with some workarounds for bug 4212439.
304 */
305 private static final ConcurrentMap<CacheKey, BundleReference> cacheList
306 = new ConcurrentHashMap<>(INITIAL_CACHE_SIZE);
307
308 /**
309 * Queue for reference objects referring to class loaders or bundles.
310 */
311 private static final ReferenceQueue<Object> referenceQueue = new ReferenceQueue<>();
312
313 /**
314 * The parent bundle of this bundle.
315 * The parent bundle is searched by {@link #getObject getObject}
316 * when this bundle does not contain a particular resource.
317 */
318 protected ResourceBundle parent = null;
319
320 /**
321 * The locale for this bundle.
322 */
323 private Locale locale = null;
324
325 /**
326 * The base bundle name for this bundle.
327 */
328 private String name;
329
330 /**
331 * The flag indicating this bundle has expired in the cache.
332 */
333 private volatile boolean expired;
334
335 /**
336 * The back link to the cache key. null if this bundle isn't in
337 * the cache (yet) or has expired.
338 */
339 private volatile CacheKey cacheKey;
340
341 /**
342 * A Set of the keys contained only in this ResourceBundle.
343 */
344 private volatile Set<String> keySet;
345
346 private static final List<ResourceBundleControlProvider> providers;
347
348 static {
349 List<ResourceBundleControlProvider> list = null;
350 ServiceLoader<ResourceBundleControlProvider> serviceLoaders
351 = ServiceLoader.loadInstalled(ResourceBundleControlProvider.class);
352 for (ResourceBundleControlProvider provider : serviceLoaders) {
353 if (list == null) {
354 list = new ArrayList<>();
355 }
356 list.add(provider);
357 }
358 providers = list;
359 }
360
361 /**
362 * Sole constructor. (For invocation by subclass constructors, typically
363 * implicit.)
364 */
365 public ResourceBundle() {
366 }
367
368 /**
369 * Gets a string for the given key from this resource bundle or one of its parents.
370 * Calling this method is equivalent to calling
371 * <blockquote>
372 * <code>(String) {@link #getObject(java.lang.String) getObject}(key)</code>.
373 * </blockquote>
374 *
375 * @param key the key for the desired string
376 * @exception NullPointerException if <code>key</code> is <code>null</code>
377 * @exception MissingResourceException if no object for the given key can be found
378 * @exception ClassCastException if the object found for the given key is not a string
379 * @return the string for the given key
380 */
381 public final String getString(String key) {
382 return (String) getObject(key);
383 }
384
385 /**
386 * Gets a string array for the given key from this resource bundle or one of its parents.
387 * Calling this method is equivalent to calling
388 * <blockquote>
389 * <code>(String[]) {@link #getObject(java.lang.String) getObject}(key)</code>.
390 * </blockquote>
391 *
392 * @param key the key for the desired string array
393 * @exception NullPointerException if <code>key</code> is <code>null</code>
394 * @exception MissingResourceException if no object for the given key can be found
395 * @exception ClassCastException if the object found for the given key is not a string array
396 * @return the string array for the given key
397 */
398 public final String[] getStringArray(String key) {
399 return (String[]) getObject(key);
400 }
401
402 /**
403 * Gets an object for the given key from this resource bundle or one of its parents.
404 * This method first tries to obtain the object from this resource bundle using
405 * {@link #handleGetObject(java.lang.String) handleGetObject}.
406 * If not successful, and the parent resource bundle is not null,
407 * it calls the parent's <code>getObject</code> method.
408 * If still not successful, it throws a MissingResourceException.
409 *
410 * @param key the key for the desired object
411 * @exception NullPointerException if <code>key</code> is <code>null</code>
412 * @exception MissingResourceException if no object for the given key can be found
413 * @return the object for the given key
414 */
415 public final Object getObject(String key) {
416 Object obj = handleGetObject(key);
417 if (obj == null) {
418 if (parent != null) {
419 obj = parent.getObject(key);
420 }
421 if (obj == null) {
422 throw new MissingResourceException("Can't find resource for bundle "
423 +this.getClass().getName()
424 +", key "+key,
425 this.getClass().getName(),
426 key);
427 }
428 }
429 return obj;
430 }
431
432 /**
433 * Returns the locale of this resource bundle. This method can be used after a
434 * call to getBundle() to determine whether the resource bundle returned really
435 * corresponds to the requested locale or is a fallback.
436 *
437 * @return the locale of this resource bundle
438 */
439 public Locale getLocale() {
440 return locale;
441 }
442
443 /*
444 * Automatic determination of the ClassLoader to be used to load
445 * resources on behalf of the client.
446 */
447 private static ClassLoader getLoader(Class<?> caller) {
448 ClassLoader cl = caller == null ? null : caller.getClassLoader();
449 if (cl == null) {
450 // When the caller's loader is the boot class loader, cl is null
451 // here. In that case, ClassLoader.getSystemClassLoader() may
452 // return the same class loader that the application is
453 // using. We therefore use a wrapper ClassLoader to create a
454 // separate scope for bundles loaded on behalf of the Java
455 // runtime so that these bundles cannot be returned from the
456 // cache to the application (5048280).
457 cl = RBClassLoader.INSTANCE;
458 }
459 return cl;
460 }
461
462 /**
463 * A wrapper of ClassLoader.getSystemClassLoader().
464 */
465 private static class RBClassLoader extends ClassLoader {
466 private static final RBClassLoader INSTANCE = AccessController.doPrivileged(
467 new PrivilegedAction<RBClassLoader>() {
468 public RBClassLoader run() {
469 return new RBClassLoader();
470 }
471 });
472 private static final ClassLoader loader = ClassLoader.getSystemClassLoader();
473
474 private RBClassLoader() {
475 }
476 public Class<?> loadClass(String name) throws ClassNotFoundException {
477 if (loader != null) {
478 return loader.loadClass(name);
479 }
480 return Class.forName(name);
481 }
482 public URL getResource(String name) {
483 if (loader != null) {
484 return loader.getResource(name);
485 }
486 return ClassLoader.getSystemResource(name);
487 }
488 public InputStream getResourceAsStream(String name) {
489 if (loader != null) {
490 return loader.getResourceAsStream(name);
491 }
492 return ClassLoader.getSystemResourceAsStream(name);
493 }
494 }
495
496 /**
497 * Sets the parent bundle of this bundle.
498 * The parent bundle is searched by {@link #getObject getObject}
499 * when this bundle does not contain a particular resource.
500 *
501 * @param parent this bundle's parent bundle.
502 */
503 protected void setParent(ResourceBundle parent) {
504 assert parent != NONEXISTENT_BUNDLE;
505 this.parent = parent;
506 }
507
508 /**
509 * Key used for cached resource bundles. The key checks the base
510 * name, the locale, and the class loader to determine if the
511 * resource is a match to the requested one. The loader may be
512 * null, but the base name and the locale must have a non-null
513 * value.
514 */
515 private static class CacheKey implements Cloneable {
516 // These three are the actual keys for lookup in Map.
517 private String name;
518 private Locale locale;
519 private LoaderReference loaderRef;
520
521 // bundle format which is necessary for calling
522 // Control.needsReload().
523 private String format;
524
525 // These time values are in CacheKey so that NONEXISTENT_BUNDLE
526 // doesn't need to be cloned for caching.
527
528 // The time when the bundle has been loaded
529 private volatile long loadTime;
530
531 // The time when the bundle expires in the cache, or either
532 // Control.TTL_DONT_CACHE or Control.TTL_NO_EXPIRATION_CONTROL.
533 private volatile long expirationTime;
534
535 // Placeholder for an error report by a Throwable
536 private Throwable cause;
537
538 // Hash code value cache to avoid recalculating the hash code
539 // of this instance.
540 private int hashCodeCache;
541
542 CacheKey(String baseName, Locale locale, ClassLoader loader) {
543 this.name = baseName;
544 this.locale = locale;
545 if (loader == null) {
546 this.loaderRef = null;
547 } else {
548 loaderRef = new LoaderReference(loader, referenceQueue, this);
549 }
550 calculateHashCode();
551 }
552
553 String getName() {
554 return name;
555 }
556
557 CacheKey setName(String baseName) {
558 if (!this.name.equals(baseName)) {
559 this.name = baseName;
560 calculateHashCode();
561 }
562 return this;
563 }
564
565 Locale getLocale() {
566 return locale;
567 }
568
569 CacheKey setLocale(Locale locale) {
570 if (!this.locale.equals(locale)) {
571 this.locale = locale;
572 calculateHashCode();
573 }
574 return this;
575 }
576
577 ClassLoader getLoader() {
578 return (loaderRef != null) ? loaderRef.get() : null;
579 }
580
581 public boolean equals(Object other) {
582 if (this == other) {
583 return true;
584 }
585 try {
586 final CacheKey otherEntry = (CacheKey)other;
587 //quick check to see if they are not equal
588 if (hashCodeCache != otherEntry.hashCodeCache) {
589 return false;
590 }
591 //are the names the same?
592 if (!name.equals(otherEntry.name)) {
593 return false;
594 }
595 // are the locales the same?
596 if (!locale.equals(otherEntry.locale)) {
597 return false;
598 }
599 //are refs (both non-null) or (both null)?
600 if (loaderRef == null) {
601 return otherEntry.loaderRef == null;
602 }
603 ClassLoader loader = loaderRef.get();
604 return (otherEntry.loaderRef != null)
605 // with a null reference we can no longer find
606 // out which class loader was referenced; so
607 // treat it as unequal
608 && (loader != null)
609 && (loader == otherEntry.loaderRef.get());
610 } catch ( NullPointerException | ClassCastException e) {
611 }
612 return false;
613 }
614
615 public int hashCode() {
616 return hashCodeCache;
617 }
618
619 private void calculateHashCode() {
620 hashCodeCache = name.hashCode() << 3;
621 hashCodeCache ^= locale.hashCode();
622 ClassLoader loader = getLoader();
623 if (loader != null) {
624 hashCodeCache ^= loader.hashCode();
625 }
626 }
627
628 public Object clone() {
629 try {
630 CacheKey clone = (CacheKey) super.clone();
631 if (loaderRef != null) {
632 clone.loaderRef = new LoaderReference(loaderRef.get(),
633 referenceQueue, clone);
634 }
635 // Clear the reference to a Throwable
636 clone.cause = null;
637 return clone;
638 } catch (CloneNotSupportedException e) {
639 //this should never happen
640 throw new InternalError(e);
641 }
642 }
643
644 String getFormat() {
645 return format;
646 }
647
648 void setFormat(String format) {
649 this.format = format;
650 }
651
652 private void setCause(Throwable cause) {
653 if (this.cause == null) {
654 this.cause = cause;
655 } else {
656 // Override the cause if the previous one is
657 // ClassNotFoundException.
658 if (this.cause instanceof ClassNotFoundException) {
659 this.cause = cause;
660 }
661 }
662 }
663
664 private Throwable getCause() {
665 return cause;
666 }
667
668 public String toString() {
669 String l = locale.toString();
670 if (l.length() == 0) {
671 if (locale.getVariant().length() != 0) {
672 l = "__" + locale.getVariant();
673 } else {
674 l = "\"\"";
675 }
676 }
677 return "CacheKey[" + name + ", lc=" + l + ", ldr=" + getLoader()
678 + "(format=" + format + ")]";
679 }
680 }
681
682 /**
683 * The common interface to get a CacheKey in LoaderReference and
684 * BundleReference.
685 */
686 private static interface CacheKeyReference {
687 public CacheKey getCacheKey();
688 }
689
690 /**
691 * References to class loaders are weak references, so that they can be
692 * garbage collected when nobody else is using them. The ResourceBundle
693 * class has no reason to keep class loaders alive.
694 */
695 private static class LoaderReference extends WeakReference<ClassLoader>
696 implements CacheKeyReference {
697 private CacheKey cacheKey;
698
699 LoaderReference(ClassLoader referent, ReferenceQueue<Object> q, CacheKey key) {
700 super(referent, q);
701 cacheKey = key;
702 }
703
704 public CacheKey getCacheKey() {
705 return cacheKey;
706 }
707 }
708
709 /**
710 * References to bundles are soft references so that they can be garbage
711 * collected when they have no hard references.
712 */
713 private static class BundleReference extends SoftReference<ResourceBundle>
714 implements CacheKeyReference {
715 private CacheKey cacheKey;
716
717 BundleReference(ResourceBundle referent, ReferenceQueue<Object> q, CacheKey key) {
718 super(referent, q);
719 cacheKey = key;
720 }
721
722 public CacheKey getCacheKey() {
723 return cacheKey;
724 }
725 }
726
727 /**
728 * Gets a resource bundle using the specified base name, the default locale,
729 * and the caller's class loader. Calling this method is equivalent to calling
730 * <blockquote>
731 * <code>getBundle(baseName, Locale.getDefault(), this.getClass().getClassLoader())</code>,
732 * </blockquote>
733 * except that <code>getClassLoader()</code> is run with the security
734 * privileges of <code>ResourceBundle</code>.
735 * See {@link #getBundle(String, Locale, ClassLoader) getBundle}
736 * for a complete description of the search and instantiation strategy.
737 *
738 * @param baseName the base name of the resource bundle, a fully qualified class name
739 * @exception java.lang.NullPointerException
740 * if <code>baseName</code> is <code>null</code>
741 * @exception MissingResourceException
742 * if no resource bundle for the specified base name can be found
743 * @return a resource bundle for the given base name and the default locale
744 */
745 @CallerSensitive
746 public static final ResourceBundle getBundle(String baseName)
747 {
748 return getBundleImpl(baseName, Locale.getDefault(),
749 getLoader(Reflection.getCallerClass()),
750 getDefaultControl(baseName));
751 }
752
753 /**
754 * Returns a resource bundle using the specified base name, the
755 * default locale and the specified control. Calling this method
756 * is equivalent to calling
757 * <pre>
758 * getBundle(baseName, Locale.getDefault(),
759 * this.getClass().getClassLoader(), control),
760 * </pre>
761 * except that <code>getClassLoader()</code> is run with the security
762 * privileges of <code>ResourceBundle</code>. See {@link
763 * #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
764 * complete description of the resource bundle loading process with a
765 * <code>ResourceBundle.Control</code>.
766 *
767 * @param baseName
768 * the base name of the resource bundle, a fully qualified class
769 * name
770 * @param control
771 * the control which gives information for the resource bundle
772 * loading process
773 * @return a resource bundle for the given base name and the default
774 * locale
775 * @exception NullPointerException
776 * if <code>baseName</code> or <code>control</code> is
777 * <code>null</code>
778 * @exception MissingResourceException
779 * if no resource bundle for the specified base name can be found
780 * @exception IllegalArgumentException
781 * if the given <code>control</code> doesn't perform properly
782 * (e.g., <code>control.getCandidateLocales</code> returns null.)
783 * Note that validation of <code>control</code> is performed as
784 * needed.
785 * @since 1.6
786 */
787 @CallerSensitive
788 public static final ResourceBundle getBundle(String baseName,
789 Control control) {
790 return getBundleImpl(baseName, Locale.getDefault(),
791 getLoader(Reflection.getCallerClass()),
792 control);
793 }
794
795 /**
796 * Gets a resource bundle using the specified base name and locale,
797 * and the caller's class loader. Calling this method is equivalent to calling
798 * <blockquote>
799 * <code>getBundle(baseName, locale, this.getClass().getClassLoader())</code>,
800 * </blockquote>
801 * except that <code>getClassLoader()</code> is run with the security
802 * privileges of <code>ResourceBundle</code>.
803 * See {@link #getBundle(String, Locale, ClassLoader) getBundle}
804 * for a complete description of the search and instantiation strategy.
805 *
806 * @param baseName
807 * the base name of the resource bundle, a fully qualified class name
808 * @param locale
809 * the locale for which a resource bundle is desired
810 * @exception NullPointerException
811 * if <code>baseName</code> or <code>locale</code> is <code>null</code>
812 * @exception MissingResourceException
813 * if no resource bundle for the specified base name can be found
814 * @return a resource bundle for the given base name and locale
815 */
816 @CallerSensitive
817 public static final ResourceBundle getBundle(String baseName,
818 Locale locale)
819 {
820 return getBundleImpl(baseName, locale,
821 getLoader(Reflection.getCallerClass()),
822 getDefaultControl(baseName));
823 }
824
825 /**
826 * Returns a resource bundle using the specified base name, target
827 * locale and control, and the caller's class loader. Calling this
828 * method is equivalent to calling
829 * <pre>
830 * getBundle(baseName, targetLocale, this.getClass().getClassLoader(),
831 * control),
832 * </pre>
833 * except that <code>getClassLoader()</code> is run with the security
834 * privileges of <code>ResourceBundle</code>. See {@link
835 * #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
836 * complete description of the resource bundle loading process with a
837 * <code>ResourceBundle.Control</code>.
838 *
839 * @param baseName
840 * the base name of the resource bundle, a fully qualified
841 * class name
842 * @param targetLocale
843 * the locale for which a resource bundle is desired
844 * @param control
845 * the control which gives information for the resource
846 * bundle loading process
847 * @return a resource bundle for the given base name and a
848 * <code>Locale</code> in <code>locales</code>
849 * @exception NullPointerException
850 * if <code>baseName</code>, <code>locales</code> or
851 * <code>control</code> is <code>null</code>
852 * @exception MissingResourceException
853 * if no resource bundle for the specified base name in any
854 * of the <code>locales</code> can be found.
855 * @exception IllegalArgumentException
856 * if the given <code>control</code> doesn't perform properly
857 * (e.g., <code>control.getCandidateLocales</code> returns null.)
858 * Note that validation of <code>control</code> is performed as
859 * needed.
860 * @since 1.6
861 */
862 @CallerSensitive
863 public static final ResourceBundle getBundle(String baseName, Locale targetLocale,
864 Control control) {
865 return getBundleImpl(baseName, targetLocale,
866 getLoader(Reflection.getCallerClass()),
867 control);
868 }
869
870 /**
871 * Gets a resource bundle using the specified base name, locale, and class
872 * loader.
873 *
874 * <p>This method behaves the same as calling
875 * {@link #getBundle(String, Locale, ClassLoader, Control)} passing a
876 * default instance of {@link Control} unless another {@link Control} is
877 * provided with the {@link ResourceBundleControlProvider} SPI. Refer to the
878 * description of <a href="#modify_default_behavior">modifying the default
879 * behavior</a>.
880 *
881 * <p><a name="default_behavior"/>The following describes the default
882 * behavior.
883 *
884 * <p><code>getBundle</code> uses the base name, the specified locale, and
885 * the default locale (obtained from {@link java.util.Locale#getDefault()
886 * Locale.getDefault}) to generate a sequence of <a
887 * name="candidates"><em>candidate bundle names</em></a>. If the specified
888 * locale's language, script, country, and variant are all empty strings,
889 * then the base name is the only candidate bundle name. Otherwise, a list
890 * of candidate locales is generated from the attribute values of the
891 * specified locale (language, script, country and variant) and appended to
892 * the base name. Typically, this will look like the following:
893 *
894 * <pre>
895 * baseName + "_" + language + "_" + script + "_" + country + "_" + variant
896 * baseName + "_" + language + "_" + script + "_" + country
897 * baseName + "_" + language + "_" + script
898 * baseName + "_" + language + "_" + country + "_" + variant
899 * baseName + "_" + language + "_" + country
900 * baseName + "_" + language
901 * </pre>
902 *
903 * <p>Candidate bundle names where the final component is an empty string
904 * are omitted, along with the underscore. For example, if country is an
905 * empty string, the second and the fifth candidate bundle names above
906 * would be omitted. Also, if script is an empty string, the candidate names
907 * including script are omitted. For example, a locale with language "de"
908 * and variant "JAVA" will produce candidate names with base name
909 * "MyResource" below.
910 *
911 * <pre>
912 * MyResource_de__JAVA
913 * MyResource_de
914 * </pre>
915 *
916 * In the case that the variant contains one or more underscores ('_'), a
917 * sequence of bundle names generated by truncating the last underscore and
918 * the part following it is inserted after a candidate bundle name with the
919 * original variant. For example, for a locale with language "en", script
920 * "Latn, country "US" and variant "WINDOWS_VISTA", and bundle base name
921 * "MyResource", the list of candidate bundle names below is generated:
922 *
923 * <pre>
924 * MyResource_en_Latn_US_WINDOWS_VISTA
925 * MyResource_en_Latn_US_WINDOWS
926 * MyResource_en_Latn_US
927 * MyResource_en_Latn
928 * MyResource_en_US_WINDOWS_VISTA
929 * MyResource_en_US_WINDOWS
930 * MyResource_en_US
931 * MyResource_en
932 * </pre>
933 *
934 * <blockquote><b>Note:</b> For some <code>Locale</code>s, the list of
935 * candidate bundle names contains extra names, or the order of bundle names
936 * is slightly modified. See the description of the default implementation
937 * of {@link Control#getCandidateLocales(String, Locale)
938 * getCandidateLocales} for details.</blockquote>
939 *
940 * <p><code>getBundle</code> then iterates over the candidate bundle names
941 * to find the first one for which it can <em>instantiate</em> an actual
942 * resource bundle. It uses the default controls' {@link Control#getFormats
943 * getFormats} method, which generates two bundle names for each generated
944 * name, the first a class name and the second a properties file name. For
945 * each candidate bundle name, it attempts to create a resource bundle:
946 *
947 * <ul><li>First, it attempts to load a class using the generated class name.
948 * If such a class can be found and loaded using the specified class
949 * loader, is assignment compatible with ResourceBundle, is accessible from
950 * ResourceBundle, and can be instantiated, <code>getBundle</code> creates a
951 * new instance of this class and uses it as the <em>result resource
952 * bundle</em>.
953 *
954 * <li>Otherwise, <code>getBundle</code> attempts to locate a property
955 * resource file using the generated properties file name. It generates a
956 * path name from the candidate bundle name by replacing all "." characters
957 * with "/" and appending the string ".properties". It attempts to find a
958 * "resource" with this name using {@link
959 * java.lang.ClassLoader#getResource(java.lang.String)
960 * ClassLoader.getResource}. (Note that a "resource" in the sense of
961 * <code>getResource</code> has nothing to do with the contents of a
962 * resource bundle, it is just a container of data, such as a file.) If it
963 * finds a "resource", it attempts to create a new {@link
964 * PropertyResourceBundle} instance from its contents. If successful, this
965 * instance becomes the <em>result resource bundle</em>. </ul>
966 *
967 * <p>This continues until a result resource bundle is instantiated or the
968 * list of candidate bundle names is exhausted. If no matching resource
969 * bundle is found, the default control's {@link Control#getFallbackLocale
970 * getFallbackLocale} method is called, which returns the current default
971 * locale. A new sequence of candidate locale names is generated using this
972 * locale and and searched again, as above.
973 *
974 * <p>If still no result bundle is found, the base name alone is looked up. If
975 * this still fails, a <code>MissingResourceException</code> is thrown.
976 *
977 * <p><a name="parent_chain"/> Once a result resource bundle has been found,
978 * its <em>parent chain</em> is instantiated. If the result bundle already
979 * has a parent (perhaps because it was returned from a cache) the chain is
980 * complete.
981 *
982 * <p>Otherwise, <code>getBundle</code> examines the remainder of the
983 * candidate locale list that was used during the pass that generated the
984 * result resource bundle. (As before, candidate bundle names where the
985 * final component is an empty string are omitted.) When it comes to the
986 * end of the candidate list, it tries the plain bundle name. With each of the
987 * candidate bundle names it attempts to instantiate a resource bundle (first
988 * looking for a class and then a properties file, as described above).
989 *
990 * <p>Whenever it succeeds, it calls the previously instantiated resource
991 * bundle's {@link #setParent(java.util.ResourceBundle) setParent} method
992 * with the new resource bundle. This continues until the list of names
993 * is exhausted or the current bundle already has a non-null parent.
994 *
995 * <p>Once the parent chain is complete, the bundle is returned.
996 *
997 * <p><b>Note:</b> <code>getBundle</code> caches instantiated resource
998 * bundles and might return the same resource bundle instance multiple times.
999 *
1000 * <p><b>Note:</b>The <code>baseName</code> argument should be a fully
1001 * qualified class name. However, for compatibility with earlier versions,
1002 * Sun's Java SE Runtime Environments do not verify this, and so it is
1003 * possible to access <code>PropertyResourceBundle</code>s by specifying a
1004 * path name (using "/") instead of a fully qualified class name (using
1005 * ".").
1006 *
1007 * <p><a name="default_behavior_example"/>
1008 * <strong>Example:</strong>
1009 * <p>
1010 * The following class and property files are provided:
1011 * <pre>
1012 * MyResources.class
1013 * MyResources.properties
1014 * MyResources_fr.properties
1015 * MyResources_fr_CH.class
1016 * MyResources_fr_CH.properties
1017 * MyResources_en.properties
1018 * MyResources_es_ES.class
1019 * </pre>
1020 *
1021 * The contents of all files are valid (that is, public non-abstract
1022 * subclasses of <code>ResourceBundle</code> for the ".class" files,
1023 * syntactically correct ".properties" files). The default locale is
1024 * <code>Locale("en", "GB")</code>.
1025 *
1026 * <p>Calling <code>getBundle</code> with the locale arguments below will
1027 * instantiate resource bundles as follows:
1028 *
1029 * <table>
1030 * <tr><td>Locale("fr", "CH")</td><td>MyResources_fr_CH.class, parent MyResources_fr.properties, parent MyResources.class</td></tr>
1031 * <tr><td>Locale("fr", "FR")</td><td>MyResources_fr.properties, parent MyResources.class</td></tr>
1032 * <tr><td>Locale("de", "DE")</td><td>MyResources_en.properties, parent MyResources.class</td></tr>
1033 * <tr><td>Locale("en", "US")</td><td>MyResources_en.properties, parent MyResources.class</td></tr>
1034 * <tr><td>Locale("es", "ES")</td><td>MyResources_es_ES.class, parent MyResources.class</td></tr>
1035 * </table>
1036 *
1037 * <p>The file MyResources_fr_CH.properties is never used because it is
1038 * hidden by the MyResources_fr_CH.class. Likewise, MyResources.properties
1039 * is also hidden by MyResources.class.
1040 *
1041 * @param baseName the base name of the resource bundle, a fully qualified class name
1042 * @param locale the locale for which a resource bundle is desired
1043 * @param loader the class loader from which to load the resource bundle
1044 * @return a resource bundle for the given base name and locale
1045 * @exception java.lang.NullPointerException
1046 * if <code>baseName</code>, <code>locale</code>, or <code>loader</code> is <code>null</code>
1047 * @exception MissingResourceException
1048 * if no resource bundle for the specified base name can be found
1049 * @since 1.2
1050 */
1051 public static ResourceBundle getBundle(String baseName, Locale locale,
1052 ClassLoader loader)
1053 {
1054 if (loader == null) {
1055 throw new NullPointerException();
1056 }
1057 return getBundleImpl(baseName, locale, loader, getDefaultControl(baseName));
1058 }
1059
1060 /**
1061 * Returns a resource bundle using the specified base name, target
1062 * locale, class loader and control. Unlike the {@linkplain
1063 * #getBundle(String, Locale, ClassLoader) <code>getBundle</code>
1064 * factory methods with no <code>control</code> argument}, the given
1065 * <code>control</code> specifies how to locate and instantiate resource
1066 * bundles. Conceptually, the bundle loading process with the given
1067 * <code>control</code> is performed in the following steps.
1068 *
1069 * <p>
1070 * <ol>
1071 * <li>This factory method looks up the resource bundle in the cache for
1072 * the specified <code>baseName</code>, <code>targetLocale</code> and
1073 * <code>loader</code>. If the requested resource bundle instance is
1074 * found in the cache and the time-to-live periods of the instance and
1075 * all of its parent instances have not expired, the instance is returned
1076 * to the caller. Otherwise, this factory method proceeds with the
1077 * loading process below.</li>
1078 *
1079 * <li>The {@link ResourceBundle.Control#getFormats(String)
1080 * control.getFormats} method is called to get resource bundle formats
1081 * to produce bundle or resource names. The strings
1082 * <code>"java.class"</code> and <code>"java.properties"</code>
1083 * designate class-based and {@linkplain PropertyResourceBundle
1084 * property}-based resource bundles, respectively. Other strings
1085 * starting with <code>"java."</code> are reserved for future extensions
1086 * and must not be used for application-defined formats. Other strings
1087 * designate application-defined formats.</li>
1088 *
1089 * <li>The {@link ResourceBundle.Control#getCandidateLocales(String,
1090 * Locale) control.getCandidateLocales} method is called with the target
1091 * locale to get a list of <em>candidate <code>Locale</code>s</em> for
1092 * which resource bundles are searched.</li>
1093 *
1094 * <li>The {@link ResourceBundle.Control#newBundle(String, Locale,
1095 * String, ClassLoader, boolean) control.newBundle} method is called to
1096 * instantiate a <code>ResourceBundle</code> for the base bundle name, a
1097 * candidate locale, and a format. (Refer to the note on the cache
1098 * lookup below.) This step is iterated over all combinations of the
1099 * candidate locales and formats until the <code>newBundle</code> method
1100 * returns a <code>ResourceBundle</code> instance or the iteration has
1101 * used up all the combinations. For example, if the candidate locales
1102 * are <code>Locale("de", "DE")</code>, <code>Locale("de")</code> and
1103 * <code>Locale("")</code> and the formats are <code>"java.class"</code>
1104 * and <code>"java.properties"</code>, then the following is the
1105 * sequence of locale-format combinations to be used to call
1106 * <code>control.newBundle</code>.
1107 *
1108 * <table style="width: 50%; text-align: left; margin-left: 40px;"
1109 * border="0" cellpadding="2" cellspacing="2">
1110 * <tbody><code>
1111 * <tr>
1112 * <td
1113 * style="vertical-align: top; text-align: left; font-weight: bold; width: 50%;">Locale<br>
1114 * </td>
1115 * <td
1116 * style="vertical-align: top; text-align: left; font-weight: bold; width: 50%;">format<br>
1117 * </td>
1118 * </tr>
1119 * <tr>
1120 * <td style="vertical-align: top; width: 50%;">Locale("de", "DE")<br>
1121 * </td>
1122 * <td style="vertical-align: top; width: 50%;">java.class<br>
1123 * </td>
1124 * </tr>
1125 * <tr>
1126 * <td style="vertical-align: top; width: 50%;">Locale("de", "DE")</td>
1127 * <td style="vertical-align: top; width: 50%;">java.properties<br>
1128 * </td>
1129 * </tr>
1130 * <tr>
1131 * <td style="vertical-align: top; width: 50%;">Locale("de")</td>
1132 * <td style="vertical-align: top; width: 50%;">java.class</td>
1133 * </tr>
1134 * <tr>
1135 * <td style="vertical-align: top; width: 50%;">Locale("de")</td>
1136 * <td style="vertical-align: top; width: 50%;">java.properties</td>
1137 * </tr>
1138 * <tr>
1139 * <td style="vertical-align: top; width: 50%;">Locale("")<br>
1140 * </td>
1141 * <td style="vertical-align: top; width: 50%;">java.class</td>
1142 * </tr>
1143 * <tr>
1144 * <td style="vertical-align: top; width: 50%;">Locale("")</td>
1145 * <td style="vertical-align: top; width: 50%;">java.properties</td>
1146 * </tr>
1147 * </code></tbody>
1148 * </table>
1149 * </li>
1150 *
1151 * <li>If the previous step has found no resource bundle, proceed to
1152 * Step 6. If a bundle has been found that is a base bundle (a bundle
1153 * for <code>Locale("")</code>), and the candidate locale list only contained
1154 * <code>Locale("")</code>, return the bundle to the caller. If a bundle
1155 * has been found that is a base bundle, but the candidate locale list
1156 * contained locales other than Locale(""), put the bundle on hold and
1157 * proceed to Step 6. If a bundle has been found that is not a base
1158 * bundle, proceed to Step 7.</li>
1159 *
1160 * <li>The {@link ResourceBundle.Control#getFallbackLocale(String,
1161 * Locale) control.getFallbackLocale} method is called to get a fallback
1162 * locale (alternative to the current target locale) to try further
1163 * finding a resource bundle. If the method returns a non-null locale,
1164 * it becomes the next target locale and the loading process starts over
1165 * from Step 3. Otherwise, if a base bundle was found and put on hold in
1166 * a previous Step 5, it is returned to the caller now. Otherwise, a
1167 * MissingResourceException is thrown.</li>
1168 *
1169 * <li>At this point, we have found a resource bundle that's not the
1170 * base bundle. If this bundle set its parent during its instantiation,
1171 * it is returned to the caller. Otherwise, its <a
1172 * href="./ResourceBundle.html#parent_chain">parent chain</a> is
1173 * instantiated based on the list of candidate locales from which it was
1174 * found. Finally, the bundle is returned to the caller.</li>
1175 * </ol>
1176 *
1177 * <p>During the resource bundle loading process above, this factory
1178 * method looks up the cache before calling the {@link
1179 * Control#newBundle(String, Locale, String, ClassLoader, boolean)
1180 * control.newBundle} method. If the time-to-live period of the
1181 * resource bundle found in the cache has expired, the factory method
1182 * calls the {@link ResourceBundle.Control#needsReload(String, Locale,
1183 * String, ClassLoader, ResourceBundle, long) control.needsReload}
1184 * method to determine whether the resource bundle needs to be reloaded.
1185 * If reloading is required, the factory method calls
1186 * <code>control.newBundle</code> to reload the resource bundle. If
1187 * <code>control.newBundle</code> returns <code>null</code>, the factory
1188 * method puts a dummy resource bundle in the cache as a mark of
1189 * nonexistent resource bundles in order to avoid lookup overhead for
1190 * subsequent requests. Such dummy resource bundles are under the same
1191 * expiration control as specified by <code>control</code>.
1192 *
1193 * <p>All resource bundles loaded are cached by default. Refer to
1194 * {@link Control#getTimeToLive(String,Locale)
1195 * control.getTimeToLive} for details.
1196 *
1197 * <p>The following is an example of the bundle loading process with the
1198 * default <code>ResourceBundle.Control</code> implementation.
1199 *
1200 * <p>Conditions:
1201 * <ul>
1202 * <li>Base bundle name: <code>foo.bar.Messages</code>
1203 * <li>Requested <code>Locale</code>: {@link Locale#ITALY}</li>
1204 * <li>Default <code>Locale</code>: {@link Locale#FRENCH}</li>
1205 * <li>Available resource bundles:
1206 * <code>foo/bar/Messages_fr.properties</code> and
1207 * <code>foo/bar/Messages.properties</code></li>
1208 * </ul>
1209 *
1210 * <p>First, <code>getBundle</code> tries loading a resource bundle in
1211 * the following sequence.
1212 *
1213 * <ul>
1214 * <li>class <code>foo.bar.Messages_it_IT</code>
1215 * <li>file <code>foo/bar/Messages_it_IT.properties</code>
1216 * <li>class <code>foo.bar.Messages_it</code></li>
1217 * <li>file <code>foo/bar/Messages_it.properties</code></li>
1218 * <li>class <code>foo.bar.Messages</code></li>
1219 * <li>file <code>foo/bar/Messages.properties</code></li>
1220 * </ul>
1221 *
1222 * <p>At this point, <code>getBundle</code> finds
1223 * <code>foo/bar/Messages.properties</code>, which is put on hold
1224 * because it's the base bundle. <code>getBundle</code> calls {@link
1225 * Control#getFallbackLocale(String, Locale)
1226 * control.getFallbackLocale("foo.bar.Messages", Locale.ITALY)} which
1227 * returns <code>Locale.FRENCH</code>. Next, <code>getBundle</code>
1228 * tries loading a bundle in the following sequence.
1229 *
1230 * <ul>
1231 * <li>class <code>foo.bar.Messages_fr</code></li>
1232 * <li>file <code>foo/bar/Messages_fr.properties</code></li>
1233 * <li>class <code>foo.bar.Messages</code></li>
1234 * <li>file <code>foo/bar/Messages.properties</code></li>
1235 * </ul>
1236 *
1237 * <p><code>getBundle</code> finds
1238 * <code>foo/bar/Messages_fr.properties</code> and creates a
1239 * <code>ResourceBundle</code> instance. Then, <code>getBundle</code>
1240 * sets up its parent chain from the list of the candiate locales. Only
1241 * <code>foo/bar/Messages.properties</code> is found in the list and
1242 * <code>getBundle</code> creates a <code>ResourceBundle</code> instance
1243 * that becomes the parent of the instance for
1244 * <code>foo/bar/Messages_fr.properties</code>.
1245 *
1246 * @param baseName
1247 * the base name of the resource bundle, a fully qualified
1248 * class name
1249 * @param targetLocale
1250 * the locale for which a resource bundle is desired
1251 * @param loader
1252 * the class loader from which to load the resource bundle
1253 * @param control
1254 * the control which gives information for the resource
1255 * bundle loading process
1256 * @return a resource bundle for the given base name and locale
1257 * @exception NullPointerException
1258 * if <code>baseName</code>, <code>targetLocale</code>,
1259 * <code>loader</code>, or <code>control</code> is
1260 * <code>null</code>
1261 * @exception MissingResourceException
1262 * if no resource bundle for the specified base name can be found
1263 * @exception IllegalArgumentException
1264 * if the given <code>control</code> doesn't perform properly
1265 * (e.g., <code>control.getCandidateLocales</code> returns null.)
1266 * Note that validation of <code>control</code> is performed as
1267 * needed.
1268 * @since 1.6
1269 */
1270 public static ResourceBundle getBundle(String baseName, Locale targetLocale,
1271 ClassLoader loader, Control control) {
1272 if (loader == null || control == null) {
1273 throw new NullPointerException();
1274 }
1275 return getBundleImpl(baseName, targetLocale, loader, control);
1276 }
1277
1278 private static Control getDefaultControl(String baseName) {
1279 if (providers != null) {
1280 for (ResourceBundleControlProvider provider : providers) {
1281 Control control = provider.getControl(baseName);
1282 if (control != null) {
1283 return control;
1284 }
1285 }
1286 }
1287 return Control.INSTANCE;
1288 }
1289
1290 private static ResourceBundle getBundleImpl(String baseName, Locale locale,
1291 ClassLoader loader, Control control) {
1292 if (locale == null || control == null) {
1293 throw new NullPointerException();
1294 }
1295
1296 // We create a CacheKey here for use by this call. The base
1297 // name and loader will never change during the bundle loading
1298 // process. We have to make sure that the locale is set before
1299 // using it as a cache key.
1300 CacheKey cacheKey = new CacheKey(baseName, locale, loader);
1301 ResourceBundle bundle = null;
1302
1303 // Quick lookup of the cache.
1304 BundleReference bundleRef = cacheList.get(cacheKey);
1305 if (bundleRef != null) {
1306 bundle = bundleRef.get();
1307 bundleRef = null;
1308 }
1309
1310 // If this bundle and all of its parents are valid (not expired),
1311 // then return this bundle. If any of the bundles is expired, we
1312 // don't call control.needsReload here but instead drop into the
1313 // complete loading process below.
1314 if (isValidBundle(bundle) && hasValidParentChain(bundle)) {
1315 return bundle;
1316 }
1317
1318 // No valid bundle was found in the cache, so we need to load the
1319 // resource bundle and its parents.
1320
1321 boolean isKnownControl = (control == Control.INSTANCE) ||
1322 (control instanceof SingleFormatControl);
1323 List<String> formats = control.getFormats(baseName);
1324 if (!isKnownControl && !checkList(formats)) {
1325 throw new IllegalArgumentException("Invalid Control: getFormats");
1326 }
1327
1328 ResourceBundle baseBundle = null;
1329 for (Locale targetLocale = locale;
1330 targetLocale != null;
1331 targetLocale = control.getFallbackLocale(baseName, targetLocale)) {
1332 List<Locale> candidateLocales = control.getCandidateLocales(baseName, targetLocale);
1333 if (!isKnownControl && !checkList(candidateLocales)) {
1334 throw new IllegalArgumentException("Invalid Control: getCandidateLocales");
1335 }
1336
1337 bundle = findBundle(cacheKey, candidateLocales, formats, 0, control, baseBundle);
1338
1339 // If the loaded bundle is the base bundle and exactly for the
1340 // requested locale or the only candidate locale, then take the
1341 // bundle as the resulting one. If the loaded bundle is the base
1342 // bundle, it's put on hold until we finish processing all
1343 // fallback locales.
1344 if (isValidBundle(bundle)) {
1345 boolean isBaseBundle = Locale.ROOT.equals(bundle.locale);
1346 if (!isBaseBundle || bundle.locale.equals(locale)
1347 || (candidateLocales.size() == 1
1348 && bundle.locale.equals(candidateLocales.get(0)))) {
1349 break;
1350 }
1351
1352 // If the base bundle has been loaded, keep the reference in
1353 // baseBundle so that we can avoid any redundant loading in case
1354 // the control specify not to cache bundles.
1355 if (isBaseBundle && baseBundle == null) {
1356 baseBundle = bundle;
1357 }
1358 }
1359 }
1360
1361 if (bundle == null) {
1362 if (baseBundle == null) {
1363 throwMissingResourceException(baseName, locale, cacheKey.getCause());
1364 }
1365 bundle = baseBundle;
1366 }
1367
1368 return bundle;
1369 }
1370
1371 /**
1372 * Checks if the given <code>List</code> is not null, not empty,
1373 * not having null in its elements.
1374 */
1375 private static boolean checkList(List<?> a) {
1376 boolean valid = (a != null && !a.isEmpty());
1377 if (valid) {
1378 int size = a.size();
1379 for (int i = 0; valid && i < size; i++) {
1380 valid = (a.get(i) != null);
1381 }
1382 }
1383 return valid;
1384 }
1385
1386 private static ResourceBundle findBundle(CacheKey cacheKey,
1387 List<Locale> candidateLocales,
1388 List<String> formats,
1389 int index,
1390 Control control,
1391 ResourceBundle baseBundle) {
1392 Locale targetLocale = candidateLocales.get(index);
1393 ResourceBundle parent = null;
1394 if (index != candidateLocales.size() - 1) {
1395 parent = findBundle(cacheKey, candidateLocales, formats, index + 1,
1396 control, baseBundle);
1397 } else if (baseBundle != null && Locale.ROOT.equals(targetLocale)) {
1398 return baseBundle;
1399 }
1400
1401 // Before we do the real loading work, see whether we need to
1402 // do some housekeeping: If references to class loaders or
1403 // resource bundles have been nulled out, remove all related
1404 // information from the cache.
1405 Object ref;
1406 while ((ref = referenceQueue.poll()) != null) {
1407 cacheList.remove(((CacheKeyReference)ref).getCacheKey());
1408 }
1409
1410 // flag indicating the resource bundle has expired in the cache
1411 boolean expiredBundle = false;
1412
1413 // First, look up the cache to see if it's in the cache, without
1414 // attempting to load bundle.
1415 cacheKey.setLocale(targetLocale);
1416 ResourceBundle bundle = findBundleInCache(cacheKey, control);
1417 if (isValidBundle(bundle)) {
1418 expiredBundle = bundle.expired;
1419 if (!expiredBundle) {
1420 // If its parent is the one asked for by the candidate
1421 // locales (the runtime lookup path), we can take the cached
1422 // one. (If it's not identical, then we'd have to check the
1423 // parent's parents to be consistent with what's been
1424 // requested.)
1425 if (bundle.parent == parent) {
1426 return bundle;
1427 }
1428 // Otherwise, remove the cached one since we can't keep
1429 // the same bundles having different parents.
1430 BundleReference bundleRef = cacheList.get(cacheKey);
1431 if (bundleRef != null && bundleRef.get() == bundle) {
1432 cacheList.remove(cacheKey, bundleRef);
1433 }
1434 }
1435 }
1436
1437 if (bundle != NONEXISTENT_BUNDLE) {
1438 CacheKey constKey = (CacheKey) cacheKey.clone();
1439
1440 try {
1441 bundle = loadBundle(cacheKey, formats, control, expiredBundle);
1442 if (bundle != null) {
1443 if (bundle.parent == null) {
1444 bundle.setParent(parent);
1445 }
1446 bundle.locale = targetLocale;
1447 bundle = putBundleInCache(cacheKey, bundle, control);
1448 return bundle;
1449 }
1450
1451 // Put NONEXISTENT_BUNDLE in the cache as a mark that there's no bundle
1452 // instance for the locale.
1453 putBundleInCache(cacheKey, NONEXISTENT_BUNDLE, control);
1454 } finally {
1455 if (constKey.getCause() instanceof InterruptedException) {
1456 Thread.currentThread().interrupt();
1457 }
1458 }
1459 }
1460 return parent;
1461 }
1462
1463 private static ResourceBundle loadBundle(CacheKey cacheKey,
1464 List<String> formats,
1465 Control control,
1466 boolean reload) {
1467
1468 // Here we actually load the bundle in the order of formats
1469 // specified by the getFormats() value.
1470 Locale targetLocale = cacheKey.getLocale();
1471
1472 ResourceBundle bundle = null;
1473 int size = formats.size();
1474 for (int i = 0; i < size; i++) {
1475 String format = formats.get(i);
1476 try {
1477 bundle = control.newBundle(cacheKey.getName(), targetLocale, format,
1478 cacheKey.getLoader(), reload);
1479 } catch (LinkageError error) {
1480 // We need to handle the LinkageError case due to
1481 // inconsistent case-sensitivity in ClassLoader.
1482 // See 6572242 for details.
1483 cacheKey.setCause(error);
1484 } catch (Exception cause) {
1485 cacheKey.setCause(cause);
1486 }
1487 if (bundle != null) {
1488 // Set the format in the cache key so that it can be
1489 // used when calling needsReload later.
1490 cacheKey.setFormat(format);
1491 bundle.name = cacheKey.getName();
1492 bundle.locale = targetLocale;
1493 // Bundle provider might reuse instances. So we should make
1494 // sure to clear the expired flag here.
1495 bundle.expired = false;
1496 break;
1497 }
1498 }
1499
1500 return bundle;
1501 }
1502
1503 private static boolean isValidBundle(ResourceBundle bundle) {
1504 return bundle != null && bundle != NONEXISTENT_BUNDLE;
1505 }
1506
1507 /**
1508 * Determines whether any of resource bundles in the parent chain,
1509 * including the leaf, have expired.
1510 */
1511 private static boolean hasValidParentChain(ResourceBundle bundle) {
1512 long now = System.currentTimeMillis();
1513 while (bundle != null) {
1514 if (bundle.expired) {
1515 return false;
1516 }
1517 CacheKey key = bundle.cacheKey;
1518 if (key != null) {
1519 long expirationTime = key.expirationTime;
1520 if (expirationTime >= 0 && expirationTime <= now) {
1521 return false;
1522 }
1523 }
1524 bundle = bundle.parent;
1525 }
1526 return true;
1527 }
1528
1529 /**
1530 * Throw a MissingResourceException with proper message
1531 */
1532 private static void throwMissingResourceException(String baseName,
1533 Locale locale,
1534 Throwable cause) {
1535 // If the cause is a MissingResourceException, avoid creating
1536 // a long chain. (6355009)
1537 if (cause instanceof MissingResourceException) {
1538 cause = null;
1539 }
1540 throw new MissingResourceException("Can't find bundle for base name "
1541 + baseName + ", locale " + locale,
1542 baseName + "_" + locale, // className
1543 "", // key
1544 cause);
1545 }
1546
1547 /**
1548 * Finds a bundle in the cache. Any expired bundles are marked as
1549 * `expired' and removed from the cache upon return.
1550 *
1551 * @param cacheKey the key to look up the cache
1552 * @param control the Control to be used for the expiration control
1553 * @return the cached bundle, or null if the bundle is not found in the
1554 * cache or its parent has expired. <code>bundle.expire</code> is true
1555 * upon return if the bundle in the cache has expired.
1556 */
1557 private static ResourceBundle findBundleInCache(CacheKey cacheKey,
1558 Control control) {
1559 BundleReference bundleRef = cacheList.get(cacheKey);
1560 if (bundleRef == null) {
1561 return null;
1562 }
1563 ResourceBundle bundle = bundleRef.get();
1564 if (bundle == null) {
1565 return null;
1566 }
1567 ResourceBundle p = bundle.parent;
1568 assert p != NONEXISTENT_BUNDLE;
1569 // If the parent has expired, then this one must also expire. We
1570 // check only the immediate parent because the actual loading is
1571 // done from the root (base) to leaf (child) and the purpose of
1572 // checking is to propagate expiration towards the leaf. For
1573 // example, if the requested locale is ja_JP_JP and there are
1574 // bundles for all of the candidates in the cache, we have a list,
1575 //
1576 // base <- ja <- ja_JP <- ja_JP_JP
1577 //
1578 // If ja has expired, then it will reload ja and the list becomes a
1579 // tree.
1580 //
1581 // base <- ja (new)
1582 // " <- ja (expired) <- ja_JP <- ja_JP_JP
1583 //
1584 // When looking up ja_JP in the cache, it finds ja_JP in the cache
1585 // which references to the expired ja. Then, ja_JP is marked as
1586 // expired and removed from the cache. This will be propagated to
1587 // ja_JP_JP.
1588 //
1589 // Now, it's possible, for example, that while loading new ja_JP,
1590 // someone else has started loading the same bundle and finds the
1591 // base bundle has expired. Then, what we get from the first
1592 // getBundle call includes the expired base bundle. However, if
1593 // someone else didn't start its loading, we wouldn't know if the
1594 // base bundle has expired at the end of the loading process. The
1595 // expiration control doesn't guarantee that the returned bundle and
1596 // its parents haven't expired.
1597 //
1598 // We could check the entire parent chain to see if there's any in
1599 // the chain that has expired. But this process may never end. An
1600 // extreme case would be that getTimeToLive returns 0 and
1601 // needsReload always returns true.
1602 if (p != null && p.expired) {
1603 assert bundle != NONEXISTENT_BUNDLE;
1604 bundle.expired = true;
1605 bundle.cacheKey = null;
1606 cacheList.remove(cacheKey, bundleRef);
1607 bundle = null;
1608 } else {
1609 CacheKey key = bundleRef.getCacheKey();
1610 long expirationTime = key.expirationTime;
1611 if (!bundle.expired && expirationTime >= 0 &&
1612 expirationTime <= System.currentTimeMillis()) {
1613 // its TTL period has expired.
1614 if (bundle != NONEXISTENT_BUNDLE) {
1615 // Synchronize here to call needsReload to avoid
1616 // redundant concurrent calls for the same bundle.
1617 synchronized (bundle) {
1618 expirationTime = key.expirationTime;
1619 if (!bundle.expired && expirationTime >= 0 &&
1620 expirationTime <= System.currentTimeMillis()) {
1621 try {
1622 bundle.expired = control.needsReload(key.getName(),
1623 key.getLocale(),
1624 key.getFormat(),
1625 key.getLoader(),
1626 bundle,
1627 key.loadTime);
1628 } catch (Exception e) {
1629 cacheKey.setCause(e);
1630 }
1631 if (bundle.expired) {
1632 // If the bundle needs to be reloaded, then
1633 // remove the bundle from the cache, but
1634 // return the bundle with the expired flag
1635 // on.
1636 bundle.cacheKey = null;
1637 cacheList.remove(cacheKey, bundleRef);
1638 } else {
1639 // Update the expiration control info. and reuse
1640 // the same bundle instance
1641 setExpirationTime(key, control);
1642 }
1643 }
1644 }
1645 } else {
1646 // We just remove NONEXISTENT_BUNDLE from the cache.
1647 cacheList.remove(cacheKey, bundleRef);
1648 bundle = null;
1649 }
1650 }
1651 }
1652 return bundle;
1653 }
1654
1655 /**
1656 * Put a new bundle in the cache.
1657 *
1658 * @param cacheKey the key for the resource bundle
1659 * @param bundle the resource bundle to be put in the cache
1660 * @return the ResourceBundle for the cacheKey; if someone has put
1661 * the bundle before this call, the one found in the cache is
1662 * returned.
1663 */
1664 private static ResourceBundle putBundleInCache(CacheKey cacheKey,
1665 ResourceBundle bundle,
1666 Control control) {
1667 setExpirationTime(cacheKey, control);
1668 if (cacheKey.expirationTime != Control.TTL_DONT_CACHE) {
1669 CacheKey key = (CacheKey) cacheKey.clone();
1670 BundleReference bundleRef = new BundleReference(bundle, referenceQueue, key);
1671 bundle.cacheKey = key;
1672
1673 // Put the bundle in the cache if it's not been in the cache.
1674 BundleReference result = cacheList.putIfAbsent(key, bundleRef);
1675
1676 // If someone else has put the same bundle in the cache before
1677 // us and it has not expired, we should use the one in the cache.
1678 if (result != null) {
1679 ResourceBundle rb = result.get();
1680 if (rb != null && !rb.expired) {
1681 // Clear the back link to the cache key
1682 bundle.cacheKey = null;
1683 bundle = rb;
1684 // Clear the reference in the BundleReference so that
1685 // it won't be enqueued.
1686 bundleRef.clear();
1687 } else {
1688 // Replace the invalid (garbage collected or expired)
1689 // instance with the valid one.
1690 cacheList.put(key, bundleRef);
1691 }
1692 }
1693 }
1694 return bundle;
1695 }
1696
1697 private static void setExpirationTime(CacheKey cacheKey, Control control) {
1698 long ttl = control.getTimeToLive(cacheKey.getName(),
1699 cacheKey.getLocale());
1700 if (ttl >= 0) {
1701 // If any expiration time is specified, set the time to be
1702 // expired in the cache.
1703 long now = System.currentTimeMillis();
1704 cacheKey.loadTime = now;
1705 cacheKey.expirationTime = now + ttl;
1706 } else if (ttl >= Control.TTL_NO_EXPIRATION_CONTROL) {
1707 cacheKey.expirationTime = ttl;
1708 } else {
1709 throw new IllegalArgumentException("Invalid Control: TTL=" + ttl);
1710 }
1711 }
1712
1713 /**
1714 * Removes all resource bundles from the cache that have been loaded
1715 * using the caller's class loader.
1716 *
1717 * @since 1.6
1718 * @see ResourceBundle.Control#getTimeToLive(String,Locale)
1719 */
1720 @CallerSensitive
1721 public static final void clearCache() {
1722 clearCache(getLoader(Reflection.getCallerClass()));
1723 }
1724
1725 /**
1726 * Removes all resource bundles from the cache that have been loaded
1727 * using the given class loader.
1728 *
1729 * @param loader the class loader
1730 * @exception NullPointerException if <code>loader</code> is null
1731 * @since 1.6
1732 * @see ResourceBundle.Control#getTimeToLive(String,Locale)
1733 */
1734 public static final void clearCache(ClassLoader loader) {
1735 if (loader == null) {
1736 throw new NullPointerException();
1737 }
1738 Set<CacheKey> set = cacheList.keySet();
1739 for (CacheKey key : set) {
1740 if (key.getLoader() == loader) {
1741 set.remove(key);
1742 }
1743 }
1744 }
1745
1746 /**
1747 * Gets an object for the given key from this resource bundle.
1748 * Returns null if this resource bundle does not contain an
1749 * object for the given key.
1750 *
1751 * @param key the key for the desired object
1752 * @exception NullPointerException if <code>key</code> is <code>null</code>
1753 * @return the object for the given key, or null
1754 */
1755 protected abstract Object handleGetObject(String key);
1756
1757 /**
1758 * Returns an enumeration of the keys.
1759 *
1760 * @return an <code>Enumeration</code> of the keys contained in
1761 * this <code>ResourceBundle</code> and its parent bundles.
1762 */
1763 public abstract Enumeration<String> getKeys();
1764
1765 /**
1766 * Determines whether the given <code>key</code> is contained in
1767 * this <code>ResourceBundle</code> or its parent bundles.
1768 *
1769 * @param key
1770 * the resource <code>key</code>
1771 * @return <code>true</code> if the given <code>key</code> is
1772 * contained in this <code>ResourceBundle</code> or its
1773 * parent bundles; <code>false</code> otherwise.
1774 * @exception NullPointerException
1775 * if <code>key</code> is <code>null</code>
1776 * @since 1.6
1777 */
1778 public boolean containsKey(String key) {
1779 if (key == null) {
1780 throw new NullPointerException();
1781 }
1782 for (ResourceBundle rb = this; rb != null; rb = rb.parent) {
1783 if (rb.handleKeySet().contains(key)) {
1784 return true;
1785 }
1786 }
1787 return false;
1788 }
1789
1790 /**
1791 * Returns a <code>Set</code> of all keys contained in this
1792 * <code>ResourceBundle</code> and its parent bundles.
1793 *
1794 * @return a <code>Set</code> of all keys contained in this
1795 * <code>ResourceBundle</code> and its parent bundles.
1796 * @since 1.6
1797 */
1798 public Set<String> keySet() {
1799 Set<String> keys = new HashSet<>();
1800 for (ResourceBundle rb = this; rb != null; rb = rb.parent) {
1801 keys.addAll(rb.handleKeySet());
1802 }
1803 return keys;
1804 }
1805
1806 /**
1807 * Returns a <code>Set</code> of the keys contained <em>only</em>
1808 * in this <code>ResourceBundle</code>.
1809 *
1810 * <p>The default implementation returns a <code>Set</code> of the
1811 * keys returned by the {@link #getKeys() getKeys} method except
1812 * for the ones for which the {@link #handleGetObject(String)
1813 * handleGetObject} method returns <code>null</code>. Once the
1814 * <code>Set</code> has been created, the value is kept in this
1815 * <code>ResourceBundle</code> in order to avoid producing the
1816 * same <code>Set</code> in subsequent calls. Subclasses can
1817 * override this method for faster handling.
1818 *
1819 * @return a <code>Set</code> of the keys contained only in this
1820 * <code>ResourceBundle</code>
1821 * @since 1.6
1822 */
1823 protected Set<String> handleKeySet() {
1824 if (keySet == null) {
1825 synchronized (this) {
1826 if (keySet == null) {
1827 Set<String> keys = new HashSet<>();
1828 Enumeration<String> enumKeys = getKeys();
1829 while (enumKeys.hasMoreElements()) {
1830 String key = enumKeys.nextElement();
1831 if (handleGetObject(key) != null) {
1832 keys.add(key);
1833 }
1834 }
1835 keySet = keys;
1836 }
1837 }
1838 }
1839 return keySet;
1840 }
1841
1842
1843
1844 /**
1845 * <code>ResourceBundle.Control</code> defines a set of callback methods
1846 * that are invoked by the {@link ResourceBundle#getBundle(String,
1847 * Locale, ClassLoader, Control) ResourceBundle.getBundle} factory
1848 * methods during the bundle loading process. In other words, a
1849 * <code>ResourceBundle.Control</code> collaborates with the factory
1850 * methods for loading resource bundles. The default implementation of
1851 * the callback methods provides the information necessary for the
1852 * factory methods to perform the <a
1853 * href="./ResourceBundle.html#default_behavior">default behavior</a>.
1854 *
1855 * <p>In addition to the callback methods, the {@link
1856 * #toBundleName(String, Locale) toBundleName} and {@link
1857 * #toResourceName(String, String) toResourceName} methods are defined
1858 * primarily for convenience in implementing the callback
1859 * methods. However, the <code>toBundleName</code> method could be
1860 * overridden to provide different conventions in the organization and
1861 * packaging of localized resources. The <code>toResourceName</code>
1862 * method is <code>final</code> to avoid use of wrong resource and class
1863 * name separators.
1864 *
1865 * <p>Two factory methods, {@link #getControl(List)} and {@link
1866 * #getNoFallbackControl(List)}, provide
1867 * <code>ResourceBundle.Control</code> instances that implement common
1868 * variations of the default bundle loading process.
1869 *
1870 * <p>The formats returned by the {@link Control#getFormats(String)
1871 * getFormats} method and candidate locales returned by the {@link
1872 * ResourceBundle.Control#getCandidateLocales(String, Locale)
1873 * getCandidateLocales} method must be consistent in all
1874 * <code>ResourceBundle.getBundle</code> invocations for the same base
1875 * bundle. Otherwise, the <code>ResourceBundle.getBundle</code> methods
1876 * may return unintended bundles. For example, if only
1877 * <code>"java.class"</code> is returned by the <code>getFormats</code>
1878 * method for the first call to <code>ResourceBundle.getBundle</code>
1879 * and only <code>"java.properties"</code> for the second call, then the
1880 * second call will return the class-based one that has been cached
1881 * during the first call.
1882 *
1883 * <p>A <code>ResourceBundle.Control</code> instance must be thread-safe
1884 * if it's simultaneously used by multiple threads.
1885 * <code>ResourceBundle.getBundle</code> does not synchronize to call
1886 * the <code>ResourceBundle.Control</code> methods. The default
1887 * implementations of the methods are thread-safe.
1888 *
1889 * <p>Applications can specify <code>ResourceBundle.Control</code>
1890 * instances returned by the <code>getControl</code> factory methods or
1891 * created from a subclass of <code>ResourceBundle.Control</code> to
1892 * customize the bundle loading process. The following are examples of
1893 * changing the default bundle loading process.
1894 *
1895 * <p><b>Example 1</b>
1896 *
1897 * <p>The following code lets <code>ResourceBundle.getBundle</code> look
1898 * up only properties-based resources.
1899 *
1900 * <pre>
1901 * import java.util.*;
1902 * import static java.util.ResourceBundle.Control.*;
1903 * ...
1904 * ResourceBundle bundle =
1905 * ResourceBundle.getBundle("MyResources", new Locale("fr", "CH"),
1906 * ResourceBundle.Control.getControl(FORMAT_PROPERTIES));
1907 * </pre>
1908 *
1909 * Given the resource bundles in the <a
1910 * href="./ResourceBundle.html#default_behavior_example">example</a> in
1911 * the <code>ResourceBundle.getBundle</code> description, this
1912 * <code>ResourceBundle.getBundle</code> call loads
1913 * <code>MyResources_fr_CH.properties</code> whose parent is
1914 * <code>MyResources_fr.properties</code> whose parent is
1915 * <code>MyResources.properties</code>. (<code>MyResources_fr_CH.properties</code>
1916 * is not hidden, but <code>MyResources_fr_CH.class</code> is.)
1917 *
1918 * <p><b>Example 2</b>
1919 *
1920 * <p>The following is an example of loading XML-based bundles
1921 * using {@link Properties#loadFromXML(java.io.InputStream)
1922 * Properties.loadFromXML}.
1923 *
1924 * <pre>
1925 * ResourceBundle rb = ResourceBundle.getBundle("Messages",
1926 * new ResourceBundle.Control() {
1927 * public List<String> getFormats(String baseName) {
1928 * if (baseName == null)
1929 * throw new NullPointerException();
1930 * return Arrays.asList("xml");
1931 * }
1932 * public ResourceBundle newBundle(String baseName,
1933 * Locale locale,
1934 * String format,
1935 * ClassLoader loader,
1936 * boolean reload)
1937 * throws IllegalAccessException,
1938 * InstantiationException,
1939 * IOException {
1940 * if (baseName == null || locale == null
1941 * || format == null || loader == null)
1942 * throw new NullPointerException();
1943 * ResourceBundle bundle = null;
1944 * if (format.equals("xml")) {
1945 * String bundleName = toBundleName(baseName, locale);
1946 * String resourceName = toResourceName(bundleName, format);
1947 * InputStream stream = null;
1948 * if (reload) {
1949 * URL url = loader.getResource(resourceName);
1950 * if (url != null) {
1951 * URLConnection connection = url.openConnection();
1952 * if (connection != null) {
1953 * // Disable caches to get fresh data for
1954 * // reloading.
1955 * connection.setUseCaches(false);
1956 * stream = connection.getInputStream();
1957 * }
1958 * }
1959 * } else {
1960 * stream = loader.getResourceAsStream(resourceName);
1961 * }
1962 * if (stream != null) {
1963 * BufferedInputStream bis = new BufferedInputStream(stream);
1964 * bundle = new XMLResourceBundle(bis);
1965 * bis.close();
1966 * }
1967 * }
1968 * return bundle;
1969 * }
1970 * });
1971 *
1972 * ...
1973 *
1974 * private static class XMLResourceBundle extends ResourceBundle {
1975 * private Properties props;
1976 * XMLResourceBundle(InputStream stream) throws IOException {
1977 * props = new Properties();
1978 * props.loadFromXML(stream);
1979 * }
1980 * protected Object handleGetObject(String key) {
1981 * return props.getProperty(key);
1982 * }
1983 * public Enumeration<String> getKeys() {
1984 * ...
1985 * }
1986 * }
1987 * </pre>
1988 *
1989 * @since 1.6
1990 */
1991 public static class Control {
1992 /**
1993 * The default format <code>List</code>, which contains the strings
1994 * <code>"java.class"</code> and <code>"java.properties"</code>, in
1995 * this order. This <code>List</code> is {@linkplain
1996 * Collections#unmodifiableList(List) unmodifiable}.
1997 *
1998 * @see #getFormats(String)
1999 */
2000 public static final List<String> FORMAT_DEFAULT
2001 = Collections.unmodifiableList(Arrays.asList("java.class",
2002 "java.properties"));
2003
2004 /**
2005 * The class-only format <code>List</code> containing
2006 * <code>"java.class"</code>. This <code>List</code> is {@linkplain
2007 * Collections#unmodifiableList(List) unmodifiable}.
2008 *
2009 * @see #getFormats(String)
2010 */
2011 public static final List<String> FORMAT_CLASS
2012 = Collections.unmodifiableList(Arrays.asList("java.class"));
2013
2014 /**
2015 * The properties-only format <code>List</code> containing
2016 * <code>"java.properties"</code>. This <code>List</code> is
2017 * {@linkplain Collections#unmodifiableList(List) unmodifiable}.
2018 *
2019 * @see #getFormats(String)
2020 */
2021 public static final List<String> FORMAT_PROPERTIES
2022 = Collections.unmodifiableList(Arrays.asList("java.properties"));
2023
2024 /**
2025 * The time-to-live constant for not caching loaded resource bundle
2026 * instances.
2027 *
2028 * @see #getTimeToLive(String, Locale)
2029 */
2030 public static final long TTL_DONT_CACHE = -1;
2031
2032 /**
2033 * The time-to-live constant for disabling the expiration control
2034 * for loaded resource bundle instances in the cache.
2035 *
2036 * @see #getTimeToLive(String, Locale)
2037 */
2038 public static final long TTL_NO_EXPIRATION_CONTROL = -2;
2039
2040 private static final Control INSTANCE = new Control();
2041
2042 /**
2043 * Sole constructor. (For invocation by subclass constructors,
2044 * typically implicit.)
2045 */
2046 protected Control() {
2047 }
2048
2049 /**
2050 * Returns a <code>ResourceBundle.Control</code> in which the {@link
2051 * #getFormats(String) getFormats} method returns the specified
2052 * <code>formats</code>. The <code>formats</code> must be equal to
2053 * one of {@link Control#FORMAT_PROPERTIES}, {@link
2054 * Control#FORMAT_CLASS} or {@link
2055 * Control#FORMAT_DEFAULT}. <code>ResourceBundle.Control</code>
2056 * instances returned by this method are singletons and thread-safe.
2057 *
2058 * <p>Specifying {@link Control#FORMAT_DEFAULT} is equivalent to
2059 * instantiating the <code>ResourceBundle.Control</code> class,
2060 * except that this method returns a singleton.
2061 *
2062 * @param formats
2063 * the formats to be returned by the
2064 * <code>ResourceBundle.Control.getFormats</code> method
2065 * @return a <code>ResourceBundle.Control</code> supporting the
2066 * specified <code>formats</code>
2067 * @exception NullPointerException
2068 * if <code>formats</code> is <code>null</code>
2069 * @exception IllegalArgumentException
2070 * if <code>formats</code> is unknown
2071 */
2072 public static final Control getControl(List<String> formats) {
2073 if (formats.equals(Control.FORMAT_PROPERTIES)) {
2074 return SingleFormatControl.PROPERTIES_ONLY;
2075 }
2076 if (formats.equals(Control.FORMAT_CLASS)) {
2077 return SingleFormatControl.CLASS_ONLY;
2078 }
2079 if (formats.equals(Control.FORMAT_DEFAULT)) {
2080 return Control.INSTANCE;
2081 }
2082 throw new IllegalArgumentException();
2083 }
2084
2085 /**
2086 * Returns a <code>ResourceBundle.Control</code> in which the {@link
2087 * #getFormats(String) getFormats} method returns the specified
2088 * <code>formats</code> and the {@link
2089 * Control#getFallbackLocale(String, Locale) getFallbackLocale}
2090 * method returns <code>null</code>. The <code>formats</code> must
2091 * be equal to one of {@link Control#FORMAT_PROPERTIES}, {@link
2092 * Control#FORMAT_CLASS} or {@link Control#FORMAT_DEFAULT}.
2093 * <code>ResourceBundle.Control</code> instances returned by this
2094 * method are singletons and thread-safe.
2095 *
2096 * @param formats
2097 * the formats to be returned by the
2098 * <code>ResourceBundle.Control.getFormats</code> method
2099 * @return a <code>ResourceBundle.Control</code> supporting the
2100 * specified <code>formats</code> with no fallback
2101 * <code>Locale</code> support
2102 * @exception NullPointerException
2103 * if <code>formats</code> is <code>null</code>
2104 * @exception IllegalArgumentException
2105 * if <code>formats</code> is unknown
2106 */
2107 public static final Control getNoFallbackControl(List<String> formats) {
2108 if (formats.equals(Control.FORMAT_DEFAULT)) {
2109 return NoFallbackControl.NO_FALLBACK;
2110 }
2111 if (formats.equals(Control.FORMAT_PROPERTIES)) {
2112 return NoFallbackControl.PROPERTIES_ONLY_NO_FALLBACK;
2113 }
2114 if (formats.equals(Control.FORMAT_CLASS)) {
2115 return NoFallbackControl.CLASS_ONLY_NO_FALLBACK;
2116 }
2117 throw new IllegalArgumentException();
2118 }
2119
2120 /**
2121 * Returns a <code>List</code> of <code>String</code>s containing
2122 * formats to be used to load resource bundles for the given
2123 * <code>baseName</code>. The <code>ResourceBundle.getBundle</code>
2124 * factory method tries to load resource bundles with formats in the
2125 * order specified by the list. The list returned by this method
2126 * must have at least one <code>String</code>. The predefined
2127 * formats are <code>"java.class"</code> for class-based resource
2128 * bundles and <code>"java.properties"</code> for {@linkplain
2129 * PropertyResourceBundle properties-based} ones. Strings starting
2130 * with <code>"java."</code> are reserved for future extensions and
2131 * must not be used by application-defined formats.
2132 *
2133 * <p>It is not a requirement to return an immutable (unmodifiable)
2134 * <code>List</code>. However, the returned <code>List</code> must
2135 * not be mutated after it has been returned by
2136 * <code>getFormats</code>.
2137 *
2138 * <p>The default implementation returns {@link #FORMAT_DEFAULT} so
2139 * that the <code>ResourceBundle.getBundle</code> factory method
2140 * looks up first class-based resource bundles, then
2141 * properties-based ones.
2142 *
2143 * @param baseName
2144 * the base name of the resource bundle, a fully qualified class
2145 * name
2146 * @return a <code>List</code> of <code>String</code>s containing
2147 * formats for loading resource bundles.
2148 * @exception NullPointerException
2149 * if <code>baseName</code> is null
2150 * @see #FORMAT_DEFAULT
2151 * @see #FORMAT_CLASS
2152 * @see #FORMAT_PROPERTIES
2153 */
2154 public List<String> getFormats(String baseName) {
2155 if (baseName == null) {
2156 throw new NullPointerException();
2157 }
2158 return FORMAT_DEFAULT;
2159 }
2160
2161 /**
2162 * Returns a <code>List</code> of <code>Locale</code>s as candidate
2163 * locales for <code>baseName</code> and <code>locale</code>. This
2164 * method is called by the <code>ResourceBundle.getBundle</code>
2165 * factory method each time the factory method tries finding a
2166 * resource bundle for a target <code>Locale</code>.
2167 *
2168 * <p>The sequence of the candidate locales also corresponds to the
2169 * runtime resource lookup path (also known as the <I>parent
2170 * chain</I>), if the corresponding resource bundles for the
2171 * candidate locales exist and their parents are not defined by
2172 * loaded resource bundles themselves. The last element of the list
2173 * must be a {@linkplain Locale#ROOT root locale} if it is desired to
2174 * have the base bundle as the terminal of the parent chain.
2175 *
2176 * <p>If the given locale is equal to <code>Locale.ROOT</code> (the
2177 * root locale), a <code>List</code> containing only the root
2178 * <code>Locale</code> must be returned. In this case, the
2179 * <code>ResourceBundle.getBundle</code> factory method loads only
2180 * the base bundle as the resulting resource bundle.
2181 *
2182 * <p>It is not a requirement to return an immutable (unmodifiable)
2183 * <code>List</code>. However, the returned <code>List</code> must not
2184 * be mutated after it has been returned by
2185 * <code>getCandidateLocales</code>.
2186 *
2187 * <p>The default implementation returns a <code>List</code> containing
2188 * <code>Locale</code>s using the rules described below. In the
2189 * description below, <em>L</em>, <em>S</em>, <em>C</em> and <em>V</em>
2190 * respectively represent non-empty language, script, country, and
2191 * variant. For example, [<em>L</em>, <em>C</em>] represents a
2192 * <code>Locale</code> that has non-empty values only for language and
2193 * country. The form <em>L</em>("xx") represents the (non-empty)
2194 * language value is "xx". For all cases, <code>Locale</code>s whose
2195 * final component values are empty strings are omitted.
2196 *
2197 * <ol><li>For an input <code>Locale</code> with an empty script value,
2198 * append candidate <code>Locale</code>s by omitting the final component
2199 * one by one as below:
2200 *
2201 * <ul>
2202 * <li> [<em>L</em>, <em>C</em>, <em>V</em>]
2203 * <li> [<em>L</em>, <em>C</em>]
2204 * <li> [<em>L</em>]
2205 * <li> <code>Locale.ROOT</code>
2206 * </ul>
2207 *
2208 * <li>For an input <code>Locale</code> with a non-empty script value,
2209 * append candidate <code>Locale</code>s by omitting the final component
2210 * up to language, then append candidates generated from the
2211 * <code>Locale</code> with country and variant restored:
2212 *
2213 * <ul>
2214 * <li> [<em>L</em>, <em>S</em>, <em>C</em>, <em>V</em>]
2215 * <li> [<em>L</em>, <em>S</em>, <em>C</em>]
2216 * <li> [<em>L</em>, <em>S</em>]
2217 * <li> [<em>L</em>, <em>C</em>, <em>V</em>]
2218 * <li> [<em>L</em>, <em>C</em>]
2219 * <li> [<em>L</em>]
2220 * <li> <code>Locale.ROOT</code>
2221 * </ul>
2222 *
2223 * <li>For an input <code>Locale</code> with a variant value consisting
2224 * of multiple subtags separated by underscore, generate candidate
2225 * <code>Locale</code>s by omitting the variant subtags one by one, then
2226 * insert them after every occurence of <code> Locale</code>s with the
2227 * full variant value in the original list. For example, if the
2228 * the variant consists of two subtags <em>V1</em> and <em>V2</em>:
2229 *
2230 * <ul>
2231 * <li> [<em>L</em>, <em>S</em>, <em>C</em>, <em>V1</em>, <em>V2</em>]
2232 * <li> [<em>L</em>, <em>S</em>, <em>C</em>, <em>V1</em>]
2233 * <li> [<em>L</em>, <em>S</em>, <em>C</em>]
2234 * <li> [<em>L</em>, <em>S</em>]
2235 * <li> [<em>L</em>, <em>C</em>, <em>V1</em>, <em>V2</em>]
2236 * <li> [<em>L</em>, <em>C</em>, <em>V1</em>]
2237 * <li> [<em>L</em>, <em>C</em>]
2238 * <li> [<em>L</em>]
2239 * <li> <code>Locale.ROOT</code>
2240 * </ul>
2241 *
2242 * <li>Special cases for Chinese. When an input <code>Locale</code> has the
2243 * language "zh" (Chinese) and an empty script value, either "Hans" (Simplified) or
2244 * "Hant" (Traditional) might be supplied, depending on the country.
2245 * When the country is "CN" (China) or "SG" (Singapore), "Hans" is supplied.
2246 * When the country is "HK" (Hong Kong SAR China), "MO" (Macau SAR China),
2247 * or "TW" (Taiwan), "Hant" is supplied. For all other countries or when the country
2248 * is empty, no script is supplied. For example, for <code>Locale("zh", "CN")
2249 * </code>, the candidate list will be:
2250 * <ul>
2251 * <li> [<em>L</em>("zh"), <em>S</em>("Hans"), <em>C</em>("CN")]
2252 * <li> [<em>L</em>("zh"), <em>S</em>("Hans")]
2253 * <li> [<em>L</em>("zh"), <em>C</em>("CN")]
2254 * <li> [<em>L</em>("zh")]
2255 * <li> <code>Locale.ROOT</code>
2256 * </ul>
2257 *
2258 * For <code>Locale("zh", "TW")</code>, the candidate list will be:
2259 * <ul>
2260 * <li> [<em>L</em>("zh"), <em>S</em>("Hant"), <em>C</em>("TW")]
2261 * <li> [<em>L</em>("zh"), <em>S</em>("Hant")]
2262 * <li> [<em>L</em>("zh"), <em>C</em>("TW")]
2263 * <li> [<em>L</em>("zh")]
2264 * <li> <code>Locale.ROOT</code>
2265 * </ul>
2266 *
2267 * <li>Special cases for Norwegian. Both <code>Locale("no", "NO",
2268 * "NY")</code> and <code>Locale("nn", "NO")</code> represent Norwegian
2269 * Nynorsk. When a locale's language is "nn", the standard candidate
2270 * list is generated up to [<em>L</em>("nn")], and then the following
2271 * candidates are added:
2272 *
2273 * <ul><li> [<em>L</em>("no"), <em>C</em>("NO"), <em>V</em>("NY")]
2274 * <li> [<em>L</em>("no"), <em>C</em>("NO")]
2275 * <li> [<em>L</em>("no")]
2276 * <li> <code>Locale.ROOT</code>
2277 * </ul>
2278 *
2279 * If the locale is exactly <code>Locale("no", "NO", "NY")</code>, it is first
2280 * converted to <code>Locale("nn", "NO")</code> and then the above procedure is
2281 * followed.
2282 *
2283 * <p>Also, Java treats the language "no" as a synonym of Norwegian
2284 * Bokmål "nb". Except for the single case <code>Locale("no",
2285 * "NO", "NY")</code> (handled above), when an input <code>Locale</code>
2286 * has language "no" or "nb", candidate <code>Locale</code>s with
2287 * language code "no" and "nb" are interleaved, first using the
2288 * requested language, then using its synonym. For example,
2289 * <code>Locale("nb", "NO", "POSIX")</code> generates the following
2290 * candidate list:
2291 *
2292 * <ul>
2293 * <li> [<em>L</em>("nb"), <em>C</em>("NO"), <em>V</em>("POSIX")]
2294 * <li> [<em>L</em>("no"), <em>C</em>("NO"), <em>V</em>("POSIX")]
2295 * <li> [<em>L</em>("nb"), <em>C</em>("NO")]
2296 * <li> [<em>L</em>("no"), <em>C</em>("NO")]
2297 * <li> [<em>L</em>("nb")]
2298 * <li> [<em>L</em>("no")]
2299 * <li> <code>Locale.ROOT</code>
2300 * </ul>
2301 *
2302 * <code>Locale("no", "NO", "POSIX")</code> would generate the same list
2303 * except that locales with "no" would appear before the corresponding
2304 * locales with "nb".</li>
2305 *
2306 * </li>
2307 * </ol>
2308 *
2309 * <p>The default implementation uses an {@link ArrayList} that
2310 * overriding implementations may modify before returning it to the
2311 * caller. However, a subclass must not modify it after it has
2312 * been returned by <code>getCandidateLocales</code>.
2313 *
2314 * <p>For example, if the given <code>baseName</code> is "Messages"
2315 * and the given <code>locale</code> is
2316 * <code>Locale("ja", "", "XX")</code>, then a
2317 * <code>List</code> of <code>Locale</code>s:
2318 * <pre>
2319 * Locale("ja", "", "XX")
2320 * Locale("ja")
2321 * Locale.ROOT
2322 * </pre>
2323 * is returned. And if the resource bundles for the "ja" and
2324 * "" <code>Locale</code>s are found, then the runtime resource
2325 * lookup path (parent chain) is:
2326 * <pre>
2327 * Messages_ja -> Messages
2328 * </pre>
2329 *
2330 * @param baseName
2331 * the base name of the resource bundle, a fully
2332 * qualified class name
2333 * @param locale
2334 * the locale for which a resource bundle is desired
2335 * @return a <code>List</code> of candidate
2336 * <code>Locale</code>s for the given <code>locale</code>
2337 * @exception NullPointerException
2338 * if <code>baseName</code> or <code>locale</code> is
2339 * <code>null</code>
2340 */
2341 public List<Locale> getCandidateLocales(String baseName, Locale locale) {
2342 if (baseName == null) {
2343 throw new NullPointerException();
2344 }
2345 return new ArrayList<>(CANDIDATES_CACHE.get(locale.getBaseLocale()));
2346 }
2347
2348 private static final CandidateListCache CANDIDATES_CACHE = new CandidateListCache();
2349
2350 private static class CandidateListCache extends LocaleObjectCache<BaseLocale, List<Locale>> {
2351 protected List<Locale> createObject(BaseLocale base) {
2352 String language = base.getLanguage();
2353 String script = base.getScript();
2354 String region = base.getRegion();
2355 String variant = base.getVariant();
2356
2357 // Special handling for Norwegian
2358 boolean isNorwegianBokmal = false;
2359 boolean isNorwegianNynorsk = false;
2360 if (language.equals("no")) {
2361 if (region.equals("NO") && variant.equals("NY")) {
2362 variant = "";
2363 isNorwegianNynorsk = true;
2364 } else {
2365 isNorwegianBokmal = true;
2366 }
2367 }
2368 if (language.equals("nb") || isNorwegianBokmal) {
2369 List<Locale> tmpList = getDefaultList("nb", script, region, variant);
2370 // Insert a locale replacing "nb" with "no" for every list entry
2371 List<Locale> bokmalList = new LinkedList<>();
2372 for (Locale l : tmpList) {
2373 bokmalList.add(l);
2374 if (l.getLanguage().length() == 0) {
2375 break;
2376 }
2377 bokmalList.add(Locale.getInstance("no", l.getScript(), l.getCountry(),
2378 l.getVariant(), null));
2379 }
2380 return bokmalList;
2381 } else if (language.equals("nn") || isNorwegianNynorsk) {
2382 // Insert no_NO_NY, no_NO, no after nn
2383 List<Locale> nynorskList = getDefaultList("nn", script, region, variant);
2384 int idx = nynorskList.size() - 1;
2385 nynorskList.add(idx++, Locale.getInstance("no", "NO", "NY"));
2386 nynorskList.add(idx++, Locale.getInstance("no", "NO", ""));
2387 nynorskList.add(idx++, Locale.getInstance("no", "", ""));
2388 return nynorskList;
2389 }
2390 // Special handling for Chinese
2391 else if (language.equals("zh")) {
2392 if (script.length() == 0 && region.length() > 0) {
2393 // Supply script for users who want to use zh_Hans/zh_Hant
2394 // as bundle names (recommended for Java7+)
2395 switch (region) {
2396 case "TW":
2397 case "HK":
2398 case "MO":
2399 script = "Hant";
2400 break;
2401 case "CN":
2402 case "SG":
2403 script = "Hans";
2404 break;
2405 }
2406 } else if (script.length() > 0 && region.length() == 0) {
2407 // Supply region(country) for users who still package Chinese
2408 // bundles using old convension.
2409 switch (script) {
2410 case "Hans":
2411 region = "CN";
2412 break;
2413 case "Hant":
2414 region = "TW";
2415 break;
2416 }
2417 }
2418 }
2419
2420 return getDefaultList(language, script, region, variant);
2421 }
2422
2423 private static List<Locale> getDefaultList(String language, String script, String region, String variant) {
2424 List<String> variants = null;
2425
2426 if (variant.length() > 0) {
2427 variants = new LinkedList<>();
2428 int idx = variant.length();
2429 while (idx != -1) {
2430 variants.add(variant.substring(0, idx));
2431 idx = variant.lastIndexOf('_', --idx);
2432 }
2433 }
2434
2435 List<Locale> list = new LinkedList<>();
2436
2437 if (variants != null) {
2438 for (String v : variants) {
2439 list.add(Locale.getInstance(language, script, region, v, null));
2440 }
2441 }
2442 if (region.length() > 0) {
2443 list.add(Locale.getInstance(language, script, region, "", null));
2444 }
2445 if (script.length() > 0) {
2446 list.add(Locale.getInstance(language, script, "", "", null));
2447
2448 // With script, after truncating variant, region and script,
2449 // start over without script.
2450 if (variants != null) {
2451 for (String v : variants) {
2452 list.add(Locale.getInstance(language, "", region, v, null));
2453 }
2454 }
2455 if (region.length() > 0) {
2456 list.add(Locale.getInstance(language, "", region, "", null));
2457 }
2458 }
2459 if (language.length() > 0) {
2460 list.add(Locale.getInstance(language, "", "", "", null));
2461 }
2462 // Add root locale at the end
2463 list.add(Locale.ROOT);
2464
2465 return list;
2466 }
2467 }
2468
2469 /**
2470 * Returns a <code>Locale</code> to be used as a fallback locale for
2471 * further resource bundle searches by the
2472 * <code>ResourceBundle.getBundle</code> factory method. This method
2473 * is called from the factory method every time when no resulting
2474 * resource bundle has been found for <code>baseName</code> and
2475 * <code>locale</code>, where locale is either the parameter for
2476 * <code>ResourceBundle.getBundle</code> or the previous fallback
2477 * locale returned by this method.
2478 *
2479 * <p>The method returns <code>null</code> if no further fallback
2480 * search is desired.
2481 *
2482 * <p>The default implementation returns the {@linkplain
2483 * Locale#getDefault() default <code>Locale</code>} if the given
2484 * <code>locale</code> isn't the default one. Otherwise,
2485 * <code>null</code> is returned.
2486 *
2487 * @param baseName
2488 * the base name of the resource bundle, a fully
2489 * qualified class name for which
2490 * <code>ResourceBundle.getBundle</code> has been
2491 * unable to find any resource bundles (except for the
2492 * base bundle)
2493 * @param locale
2494 * the <code>Locale</code> for which
2495 * <code>ResourceBundle.getBundle</code> has been
2496 * unable to find any resource bundles (except for the
2497 * base bundle)
2498 * @return a <code>Locale</code> for the fallback search,
2499 * or <code>null</code> if no further fallback search
2500 * is desired.
2501 * @exception NullPointerException
2502 * if <code>baseName</code> or <code>locale</code>
2503 * is <code>null</code>
2504 */
2505 public Locale getFallbackLocale(String baseName, Locale locale) {
2506 if (baseName == null) {
2507 throw new NullPointerException();
2508 }
2509 Locale defaultLocale = Locale.getDefault();
2510 return locale.equals(defaultLocale) ? null : defaultLocale;
2511 }
2512
2513 /**
2514 * Instantiates a resource bundle for the given bundle name of the
2515 * given format and locale, using the given class loader if
2516 * necessary. This method returns <code>null</code> if there is no
2517 * resource bundle available for the given parameters. If a resource
2518 * bundle can't be instantiated due to an unexpected error, the
2519 * error must be reported by throwing an <code>Error</code> or
2520 * <code>Exception</code> rather than simply returning
2521 * <code>null</code>.
2522 *
2523 * <p>If the <code>reload</code> flag is <code>true</code>, it
2524 * indicates that this method is being called because the previously
2525 * loaded resource bundle has expired.
2526 *
2527 * <p>The default implementation instantiates a
2528 * <code>ResourceBundle</code> as follows.
2529 *
2530 * <ul>
2531 *
2532 * <li>The bundle name is obtained by calling {@link
2533 * #toBundleName(String, Locale) toBundleName(baseName,
2534 * locale)}.</li>
2535 *
2536 * <li>If <code>format</code> is <code>"java.class"</code>, the
2537 * {@link Class} specified by the bundle name is loaded by calling
2538 * {@link ClassLoader#loadClass(String)}. Then, a
2539 * <code>ResourceBundle</code> is instantiated by calling {@link
2540 * Class#newInstance()}. Note that the <code>reload</code> flag is
2541 * ignored for loading class-based resource bundles in this default
2542 * implementation.</li>
2543 *
2544 * <li>If <code>format</code> is <code>"java.properties"</code>,
2545 * {@link #toResourceName(String, String) toResourceName(bundlename,
2546 * "properties")} is called to get the resource name.
2547 * If <code>reload</code> is <code>true</code>, {@link
2548 * ClassLoader#getResource(String) load.getResource} is called
2549 * to get a {@link URL} for creating a {@link
2550 * URLConnection}. This <code>URLConnection</code> is used to
2551 * {@linkplain URLConnection#setUseCaches(boolean) disable the
2552 * caches} of the underlying resource loading layers,
2553 * and to {@linkplain URLConnection#getInputStream() get an
2554 * <code>InputStream</code>}.
2555 * Otherwise, {@link ClassLoader#getResourceAsStream(String)
2556 * loader.getResourceAsStream} is called to get an {@link
2557 * InputStream}. Then, a {@link
2558 * PropertyResourceBundle} is constructed with the
2559 * <code>InputStream</code>.</li>
2560 *
2561 * <li>If <code>format</code> is neither <code>"java.class"</code>
2562 * nor <code>"java.properties"</code>, an
2563 * <code>IllegalArgumentException</code> is thrown.</li>
2564 *
2565 * </ul>
2566 *
2567 * @param baseName
2568 * the base bundle name of the resource bundle, a fully
2569 * qualified class name
2570 * @param locale
2571 * the locale for which the resource bundle should be
2572 * instantiated
2573 * @param format
2574 * the resource bundle format to be loaded
2575 * @param loader
2576 * the <code>ClassLoader</code> to use to load the bundle
2577 * @param reload
2578 * the flag to indicate bundle reloading; <code>true</code>
2579 * if reloading an expired resource bundle,
2580 * <code>false</code> otherwise
2581 * @return the resource bundle instance,
2582 * or <code>null</code> if none could be found.
2583 * @exception NullPointerException
2584 * if <code>bundleName</code>, <code>locale</code>,
2585 * <code>format</code>, or <code>loader</code> is
2586 * <code>null</code>, or if <code>null</code> is returned by
2587 * {@link #toBundleName(String, Locale) toBundleName}
2588 * @exception IllegalArgumentException
2589 * if <code>format</code> is unknown, or if the resource
2590 * found for the given parameters contains malformed data.
2591 * @exception ClassCastException
2592 * if the loaded class cannot be cast to <code>ResourceBundle</code>
2593 * @exception IllegalAccessException
2594 * if the class or its nullary constructor is not
2595 * accessible.
2596 * @exception InstantiationException
2597 * if the instantiation of a class fails for some other
2598 * reason.
2599 * @exception ExceptionInInitializerError
2600 * if the initialization provoked by this method fails.
2601 * @exception SecurityException
2602 * If a security manager is present and creation of new
2603 * instances is denied. See {@link Class#newInstance()}
2604 * for details.
2605 * @exception IOException
2606 * if an error occurred when reading resources using
2607 * any I/O operations
2608 */
2609 public ResourceBundle newBundle(String baseName, Locale locale, String format,
2610 ClassLoader loader, boolean reload)
2611 throws IllegalAccessException, InstantiationException, IOException {
2612 String bundleName = toBundleName(baseName, locale);
2613 ResourceBundle bundle = null;
2614 if (format.equals("java.class")) {
2615 try {
2616 @SuppressWarnings("unchecked")
2617 Class<? extends ResourceBundle> bundleClass
2618 = (Class<? extends ResourceBundle>)loader.loadClass(bundleName);
2619
2620 // If the class isn't a ResourceBundle subclass, throw a
2621 // ClassCastException.
2622 if (ResourceBundle.class.isAssignableFrom(bundleClass)) {
2623 bundle = bundleClass.newInstance();
2624 } else {
2625 throw new ClassCastException(bundleClass.getName()
2626 + " cannot be cast to ResourceBundle");
2627 }
2628 } catch (ClassNotFoundException e) {
2629 }
2630 } else if (format.equals("java.properties")) {
2631 final String resourceName = toResourceName(bundleName, "properties");
2632 final ClassLoader classLoader = loader;
2633 final boolean reloadFlag = reload;
2634 InputStream stream = null;
2635 try {
2636 stream = AccessController.doPrivileged(
2637 new PrivilegedExceptionAction<InputStream>() {
2638 public InputStream run() throws IOException {
2639 InputStream is = null;
2640 if (reloadFlag) {
2641 URL url = classLoader.getResource(resourceName);
2642 if (url != null) {
2643 URLConnection connection = url.openConnection();
2644 if (connection != null) {
2645 // Disable caches to get fresh data for
2646 // reloading.
2647 connection.setUseCaches(false);
2648 is = connection.getInputStream();
2649 }
2650 }
2651 } else {
2652 is = classLoader.getResourceAsStream(resourceName);
2653 }
2654 return is;
2655 }
2656 });
2657 } catch (PrivilegedActionException e) {
2658 throw (IOException) e.getException();
2659 }
2660 if (stream != null) {
2661 try {
2662 bundle = new PropertyResourceBundle(stream);
2663 } finally {
2664 stream.close();
2665 }
2666 }
2667 } else {
2668 throw new IllegalArgumentException("unknown format: " + format);
2669 }
2670 return bundle;
2671 }
2672
2673 /**
2674 * Returns the time-to-live (TTL) value for resource bundles that
2675 * are loaded under this
2676 * <code>ResourceBundle.Control</code>. Positive time-to-live values
2677 * specify the number of milliseconds a bundle can remain in the
2678 * cache without being validated against the source data from which
2679 * it was constructed. The value 0 indicates that a bundle must be
2680 * validated each time it is retrieved from the cache. {@link
2681 * #TTL_DONT_CACHE} specifies that loaded resource bundles are not
2682 * put in the cache. {@link #TTL_NO_EXPIRATION_CONTROL} specifies
2683 * that loaded resource bundles are put in the cache with no
2684 * expiration control.
2685 *
2686 * <p>The expiration affects only the bundle loading process by the
2687 * <code>ResourceBundle.getBundle</code> factory method. That is,
2688 * if the factory method finds a resource bundle in the cache that
2689 * has expired, the factory method calls the {@link
2690 * #needsReload(String, Locale, String, ClassLoader, ResourceBundle,
2691 * long) needsReload} method to determine whether the resource
2692 * bundle needs to be reloaded. If <code>needsReload</code> returns
2693 * <code>true</code>, the cached resource bundle instance is removed
2694 * from the cache. Otherwise, the instance stays in the cache,
2695 * updated with the new TTL value returned by this method.
2696 *
2697 * <p>All cached resource bundles are subject to removal from the
2698 * cache due to memory constraints of the runtime environment.
2699 * Returning a large positive value doesn't mean to lock loaded
2700 * resource bundles in the cache.
2701 *
2702 * <p>The default implementation returns {@link #TTL_NO_EXPIRATION_CONTROL}.
2703 *
2704 * @param baseName
2705 * the base name of the resource bundle for which the
2706 * expiration value is specified.
2707 * @param locale
2708 * the locale of the resource bundle for which the
2709 * expiration value is specified.
2710 * @return the time (0 or a positive millisecond offset from the
2711 * cached time) to get loaded bundles expired in the cache,
2712 * {@link #TTL_NO_EXPIRATION_CONTROL} to disable the
2713 * expiration control, or {@link #TTL_DONT_CACHE} to disable
2714 * caching.
2715 * @exception NullPointerException
2716 * if <code>baseName</code> or <code>locale</code> is
2717 * <code>null</code>
2718 */
2719 public long getTimeToLive(String baseName, Locale locale) {
2720 if (baseName == null || locale == null) {
2721 throw new NullPointerException();
2722 }
2723 return TTL_NO_EXPIRATION_CONTROL;
2724 }
2725
2726 /**
2727 * Determines if the expired <code>bundle</code> in the cache needs
2728 * to be reloaded based on the loading time given by
2729 * <code>loadTime</code> or some other criteria. The method returns
2730 * <code>true</code> if reloading is required; <code>false</code>
2731 * otherwise. <code>loadTime</code> is a millisecond offset since
2732 * the <a href="Calendar.html#Epoch"> <code>Calendar</code>
2733 * Epoch</a>.
2734 *
2735 * The calling <code>ResourceBundle.getBundle</code> factory method
2736 * calls this method on the <code>ResourceBundle.Control</code>
2737 * instance used for its current invocation, not on the instance
2738 * used in the invocation that originally loaded the resource
2739 * bundle.
2740 *
2741 * <p>The default implementation compares <code>loadTime</code> and
2742 * the last modified time of the source data of the resource
2743 * bundle. If it's determined that the source data has been modified
2744 * since <code>loadTime</code>, <code>true</code> is
2745 * returned. Otherwise, <code>false</code> is returned. This
2746 * implementation assumes that the given <code>format</code> is the
2747 * same string as its file suffix if it's not one of the default
2748 * formats, <code>"java.class"</code> or
2749 * <code>"java.properties"</code>.
2750 *
2751 * @param baseName
2752 * the base bundle name of the resource bundle, a
2753 * fully qualified class name
2754 * @param locale
2755 * the locale for which the resource bundle
2756 * should be instantiated
2757 * @param format
2758 * the resource bundle format to be loaded
2759 * @param loader
2760 * the <code>ClassLoader</code> to use to load the bundle
2761 * @param bundle
2762 * the resource bundle instance that has been expired
2763 * in the cache
2764 * @param loadTime
2765 * the time when <code>bundle</code> was loaded and put
2766 * in the cache
2767 * @return <code>true</code> if the expired bundle needs to be
2768 * reloaded; <code>false</code> otherwise.
2769 * @exception NullPointerException
2770 * if <code>baseName</code>, <code>locale</code>,
2771 * <code>format</code>, <code>loader</code>, or
2772 * <code>bundle</code> is <code>null</code>
2773 */
2774 public boolean needsReload(String baseName, Locale locale,
2775 String format, ClassLoader loader,
2776 ResourceBundle bundle, long loadTime) {
2777 if (bundle == null) {
2778 throw new NullPointerException();
2779 }
2780 if (format.equals("java.class") || format.equals("java.properties")) {
2781 format = format.substring(5);
2782 }
2783 boolean result = false;
2784 try {
2785 String resourceName = toResourceName(toBundleName(baseName, locale), format);
2786 URL url = loader.getResource(resourceName);
2787 if (url != null) {
2788 long lastModified = 0;
2789 URLConnection connection = url.openConnection();
2790 if (connection != null) {
2791 // disable caches to get the correct data
2792 connection.setUseCaches(false);
2793 if (connection instanceof JarURLConnection) {
2794 JarEntry ent = ((JarURLConnection)connection).getJarEntry();
2795 if (ent != null) {
2796 lastModified = ent.getTime();
2797 if (lastModified == -1) {
2798 lastModified = 0;
2799 }
2800 }
2801 } else {
2802 lastModified = connection.getLastModified();
2803 }
2804 }
2805 result = lastModified >= loadTime;
2806 }
2807 } catch (NullPointerException npe) {
2808 throw npe;
2809 } catch (Exception e) {
2810 // ignore other exceptions
2811 }
2812 return result;
2813 }
2814
2815 /**
2816 * Converts the given <code>baseName</code> and <code>locale</code>
2817 * to the bundle name. This method is called from the default
2818 * implementation of the {@link #newBundle(String, Locale, String,
2819 * ClassLoader, boolean) newBundle} and {@link #needsReload(String,
2820 * Locale, String, ClassLoader, ResourceBundle, long) needsReload}
2821 * methods.
2822 *
2823 * <p>This implementation returns the following value:
2824 * <pre>
2825 * baseName + "_" + language + "_" + script + "_" + country + "_" + variant
2826 * </pre>
2827 * where <code>language</code>, <code>script</code>, <code>country</code>,
2828 * and <code>variant</code> are the language, script, country, and variant
2829 * values of <code>locale</code>, respectively. Final component values that
2830 * are empty Strings are omitted along with the preceding '_'. When the
2831 * script is empty, the script value is ommitted along with the preceding '_'.
2832 * If all of the values are empty strings, then <code>baseName</code>
2833 * is returned.
2834 *
2835 * <p>For example, if <code>baseName</code> is
2836 * <code>"baseName"</code> and <code>locale</code> is
2837 * <code>Locale("ja", "", "XX")</code>, then
2838 * <code>"baseName_ja_ _XX"</code> is returned. If the given
2839 * locale is <code>Locale("en")</code>, then
2840 * <code>"baseName_en"</code> is returned.
2841 *
2842 * <p>Overriding this method allows applications to use different
2843 * conventions in the organization and packaging of localized
2844 * resources.
2845 *
2846 * @param baseName
2847 * the base name of the resource bundle, a fully
2848 * qualified class name
2849 * @param locale
2850 * the locale for which a resource bundle should be
2851 * loaded
2852 * @return the bundle name for the resource bundle
2853 * @exception NullPointerException
2854 * if <code>baseName</code> or <code>locale</code>
2855 * is <code>null</code>
2856 */
2857 public String toBundleName(String baseName, Locale locale) {
2858 if (locale == Locale.ROOT) {
2859 return baseName;
2860 }
2861
2862 String language = locale.getLanguage();
2863 String script = locale.getScript();
2864 String country = locale.getCountry();
2865 String variant = locale.getVariant();
2866
2867 if (language == "" && country == "" && variant == "") {
2868 return baseName;
2869 }
2870
2871 StringBuilder sb = new StringBuilder(baseName);
2872 sb.append('_');
2873 if (script != "") {
2874 if (variant != "") {
2875 sb.append(language).append('_').append(script).append('_').append(country).append('_').append(variant);
2876 } else if (country != "") {
2877 sb.append(language).append('_').append(script).append('_').append(country);
2878 } else {
2879 sb.append(language).append('_').append(script);
2880 }
2881 } else {
2882 if (variant != "") {
2883 sb.append(language).append('_').append(country).append('_').append(variant);
2884 } else if (country != "") {
2885 sb.append(language).append('_').append(country);
2886 } else {
2887 sb.append(language);
2888 }
2889 }
2890 return sb.toString();
2891
2892 }
2893
2894 /**
2895 * Converts the given <code>bundleName</code> to the form required
2896 * by the {@link ClassLoader#getResource ClassLoader.getResource}
2897 * method by replacing all occurrences of <code>'.'</code> in
2898 * <code>bundleName</code> with <code>'/'</code> and appending a
2899 * <code>'.'</code> and the given file <code>suffix</code>. For
2900 * example, if <code>bundleName</code> is
2901 * <code>"foo.bar.MyResources_ja_JP"</code> and <code>suffix</code>
2902 * is <code>"properties"</code>, then
2903 * <code>"foo/bar/MyResources_ja_JP.properties"</code> is returned.
2904 *
2905 * @param bundleName
2906 * the bundle name
2907 * @param suffix
2908 * the file type suffix
2909 * @return the converted resource name
2910 * @exception NullPointerException
2911 * if <code>bundleName</code> or <code>suffix</code>
2912 * is <code>null</code>
2913 */
2914 public final String toResourceName(String bundleName, String suffix) {
2915 StringBuilder sb = new StringBuilder(bundleName.length() + 1 + suffix.length());
2916 sb.append(bundleName.replace('.', '/')).append('.').append(suffix);
2917 return sb.toString();
2918 }
2919 }
2920
2921 private static class SingleFormatControl extends Control {
2922 private static final Control PROPERTIES_ONLY
2923 = new SingleFormatControl(FORMAT_PROPERTIES);
2924
2925 private static final Control CLASS_ONLY
2926 = new SingleFormatControl(FORMAT_CLASS);
2927
2928 private final List<String> formats;
2929
2930 protected SingleFormatControl(List<String> formats) {
2931 this.formats = formats;
2932 }
2933
2934 public List<String> getFormats(String baseName) {
2935 if (baseName == null) {
2936 throw new NullPointerException();
2937 }
2938 return formats;
2939 }
2940 }
2941
2942 private static final class NoFallbackControl extends SingleFormatControl {
2943 private static final Control NO_FALLBACK
2944 = new NoFallbackControl(FORMAT_DEFAULT);
2945
2946 private static final Control PROPERTIES_ONLY_NO_FALLBACK
2947 = new NoFallbackControl(FORMAT_PROPERTIES);
2948
2949 private static final Control CLASS_ONLY_NO_FALLBACK
2950 = new NoFallbackControl(FORMAT_CLASS);
2951
2952 protected NoFallbackControl(List<String> formats) {
2953 super(formats);
2954 }
2955
2956 public Locale getFallbackLocale(String baseName, Locale locale) {
2957 if (baseName == null || locale == null) {
2958 throw new NullPointerException();
2959 }
2960 return null;
2961 }
2962 }
2963 }