0001 /*
0002 * Copyright 1996-2006 Sun Microsystems, Inc. All Rights Reserved.
0003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0004 *
0005 * This code is free software; you can redistribute it and/or modify it
0006 * under the terms of the GNU General Public License version 2 only, as
0007 * published by the Free Software Foundation. Sun designates this
0008 * particular file as subject to the "Classpath" exception as provided
0009 * by Sun in the LICENSE file that accompanied this code.
0010 *
0011 * This code is distributed in the hope that it will be useful, but WITHOUT
0012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0014 * version 2 for more details (a copy is included in the LICENSE file that
0015 * accompanied this code).
0016 *
0017 * You should have received a copy of the GNU General Public License version
0018 * 2 along with this work; if not, write to the Free Software Foundation,
0019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0020 *
0021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
0022 * CA 95054 USA or visit www.sun.com if you need additional information or
0023 * have any questions.
0024 */
0025
0026 /*
0027 * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
0028 * (C) Copyright IBM Corp. 1996 - 1999 - All Rights Reserved
0029 *
0030 * The original version of this source code and documentation
0031 * is copyrighted and owned by Taligent, Inc., a wholly-owned
0032 * subsidiary of IBM. These materials are provided under terms
0033 * of a License Agreement between Taligent and Sun. This technology
0034 * is protected by multiple US and International patents.
0035 *
0036 * This notice and attribution to Taligent may not be removed.
0037 * Taligent is a registered trademark of Taligent, Inc.
0038 *
0039 */
0040
0041 package java.util;
0042
0043 import java.io.IOException;
0044 import java.io.InputStream;
0045 import java.lang.ref.ReferenceQueue;
0046 import java.lang.ref.SoftReference;
0047 import java.lang.ref.WeakReference;
0048 import java.net.JarURLConnection;
0049 import java.net.URL;
0050 import java.net.URLConnection;
0051 import java.security.AccessController;
0052 import java.security.PrivilegedAction;
0053 import java.security.PrivilegedActionException;
0054 import java.security.PrivilegedExceptionAction;
0055 import java.util.concurrent.ConcurrentHashMap;
0056 import java.util.concurrent.ConcurrentMap;
0057 import java.util.jar.JarEntry;
0058
0059 /**
0060 *
0061 * Resource bundles contain locale-specific objects.
0062 * When your program needs a locale-specific resource,
0063 * a <code>String</code> for example, your program can load it
0064 * from the resource bundle that is appropriate for the
0065 * current user's locale. In this way, you can write
0066 * program code that is largely independent of the user's
0067 * locale isolating most, if not all, of the locale-specific
0068 * information in resource bundles.
0069 *
0070 * <p>
0071 * This allows you to write programs that can:
0072 * <UL type=SQUARE>
0073 * <LI> be easily localized, or translated, into different languages
0074 * <LI> handle multiple locales at once
0075 * <LI> be easily modified later to support even more locales
0076 * </UL>
0077 *
0078 * <P>
0079 * Resource bundles belong to families whose members share a common base
0080 * name, but whose names also have additional components that identify
0081 * their locales. For example, the base name of a family of resource
0082 * bundles might be "MyResources". The family should have a default
0083 * resource bundle which simply has the same name as its family -
0084 * "MyResources" - and will be used as the bundle of last resort if a
0085 * specific locale is not supported. The family can then provide as
0086 * many locale-specific members as needed, for example a German one
0087 * named "MyResources_de".
0088 *
0089 * <P>
0090 * Each resource bundle in a family contains the same items, but the items have
0091 * been translated for the locale represented by that resource bundle.
0092 * For example, both "MyResources" and "MyResources_de" may have a
0093 * <code>String</code> that's used on a button for canceling operations.
0094 * In "MyResources" the <code>String</code> may contain "Cancel" and in
0095 * "MyResources_de" it may contain "Abbrechen".
0096 *
0097 * <P>
0098 * If there are different resources for different countries, you
0099 * can make specializations: for example, "MyResources_de_CH" contains objects for
0100 * the German language (de) in Switzerland (CH). If you want to only
0101 * modify some of the resources
0102 * in the specialization, you can do so.
0103 *
0104 * <P>
0105 * When your program needs a locale-specific object, it loads
0106 * the <code>ResourceBundle</code> class using the
0107 * {@link #getBundle(java.lang.String, java.util.Locale) getBundle}
0108 * method:
0109 * <blockquote>
0110 * <pre>
0111 * ResourceBundle myResources =
0112 * ResourceBundle.getBundle("MyResources", currentLocale);
0113 * </pre>
0114 * </blockquote>
0115 *
0116 * <P>
0117 * Resource bundles contain key/value pairs. The keys uniquely
0118 * identify a locale-specific object in the bundle. Here's an
0119 * example of a <code>ListResourceBundle</code> that contains
0120 * two key/value pairs:
0121 * <blockquote>
0122 * <pre>
0123 * public class MyResources extends ListResourceBundle {
0124 * protected Object[][] getContents() {
0125 * return new Object[][] {
0126 * // LOCALIZE THE SECOND STRING OF EACH ARRAY (e.g., "OK")
0127 * {"OkKey", "OK"},
0128 * {"CancelKey", "Cancel"},
0129 * // END OF MATERIAL TO LOCALIZE
0130 * };
0131 * }
0132 * }
0133 * </pre>
0134 * </blockquote>
0135 * Keys are always <code>String</code>s.
0136 * In this example, the keys are "OkKey" and "CancelKey".
0137 * In the above example, the values
0138 * are also <code>String</code>s--"OK" and "Cancel"--but
0139 * they don't have to be. The values can be any type of object.
0140 *
0141 * <P>
0142 * You retrieve an object from resource bundle using the appropriate
0143 * getter method. Because "OkKey" and "CancelKey"
0144 * are both strings, you would use <code>getString</code> to retrieve them:
0145 * <blockquote>
0146 * <pre>
0147 * button1 = new Button(myResources.getString("OkKey"));
0148 * button2 = new Button(myResources.getString("CancelKey"));
0149 * </pre>
0150 * </blockquote>
0151 * The getter methods all require the key as an argument and return
0152 * the object if found. If the object is not found, the getter method
0153 * throws a <code>MissingResourceException</code>.
0154 *
0155 * <P>
0156 * Besides <code>getString</code>, <code>ResourceBundle</code> also provides
0157 * a method for getting string arrays, <code>getStringArray</code>,
0158 * as well as a generic <code>getObject</code> method for any other
0159 * type of object. When using <code>getObject</code>, you'll
0160 * have to cast the result to the appropriate type. For example:
0161 * <blockquote>
0162 * <pre>
0163 * int[] myIntegers = (int[]) myResources.getObject("intList");
0164 * </pre>
0165 * </blockquote>
0166 *
0167 * <P>
0168 * The Java Platform provides two subclasses of <code>ResourceBundle</code>,
0169 * <code>ListResourceBundle</code> and <code>PropertyResourceBundle</code>,
0170 * that provide a fairly simple way to create resources.
0171 * As you saw briefly in a previous example, <code>ListResourceBundle</code>
0172 * manages its resource as a list of key/value pairs.
0173 * <code>PropertyResourceBundle</code> uses a properties file to manage
0174 * its resources.
0175 *
0176 * <p>
0177 * If <code>ListResourceBundle</code> or <code>PropertyResourceBundle</code>
0178 * do not suit your needs, you can write your own <code>ResourceBundle</code>
0179 * subclass. Your subclasses must override two methods: <code>handleGetObject</code>
0180 * and <code>getKeys()</code>.
0181 *
0182 * <h4>ResourceBundle.Control</h4>
0183 *
0184 * The {@link ResourceBundle.Control} class provides information necessary
0185 * to perform the bundle loading process by the <code>getBundle</code>
0186 * factory methods that take a <code>ResourceBundle.Control</code>
0187 * instance. You can implement your own subclass in order to enable
0188 * non-standard resource bundle formats, change the search strategy, or
0189 * define caching parameters. Refer to the descriptions of the class and the
0190 * {@link #getBundle(String, Locale, ClassLoader, Control) getBundle}
0191 * factory method for details.
0192 *
0193 * <h4>Cache Management</h4>
0194 *
0195 * Resource bundle instances created by the <code>getBundle</code> factory
0196 * methods are cached by default, and the factory methods return the same
0197 * resource bundle instance multiple times if it has been
0198 * cached. <code>getBundle</code> clients may clear the cache, manage the
0199 * lifetime of cached resource bundle instances using time-to-live values,
0200 * or specify not to cache resource bundle instances. Refer to the
0201 * descriptions of the {@linkplain #getBundle(String, Locale, ClassLoader,
0202 * Control) <code>getBundle</code> factory method}, {@link
0203 * #clearCache(ClassLoader) clearCache}, {@link
0204 * Control#getTimeToLive(String, Locale)
0205 * ResourceBundle.Control.getTimeToLive}, and {@link
0206 * Control#needsReload(String, Locale, String, ClassLoader, ResourceBundle,
0207 * long) ResourceBundle.Control.needsReload} for details.
0208 *
0209 * <h4>Example</h4>
0210 *
0211 * The following is a very simple example of a <code>ResourceBundle</code>
0212 * subclass, <code>MyResources</code>, that manages two resources (for a larger number of
0213 * resources you would probably use a <code>Map</code>).
0214 * Notice that you don't need to supply a value if
0215 * a "parent-level" <code>ResourceBundle</code> handles the same
0216 * key with the same value (as for the okKey below).
0217 * <blockquote>
0218 * <pre>
0219 * // default (English language, United States)
0220 * public class MyResources extends ResourceBundle {
0221 * public Object handleGetObject(String key) {
0222 * if (key.equals("okKey")) return "Ok";
0223 * if (key.equals("cancelKey")) return "Cancel";
0224 * return null;
0225 * }
0226 *
0227 * public Enumeration<String> getKeys() {
0228 * return Collections.enumeration(keySet());
0229 * }
0230 *
0231 * // Overrides handleKeySet() so that the getKeys() implementation
0232 * // can rely on the keySet() value.
0233 * protected Set<String> handleKeySet() {
0234 * return new HashSet<String>(Arrays.asList("okKey", "cancelKey"));
0235 * }
0236 * }
0237 *
0238 * // German language
0239 * public class MyResources_de extends MyResources {
0240 * public Object handleGetObject(String key) {
0241 * // don't need okKey, since parent level handles it.
0242 * if (key.equals("cancelKey")) return "Abbrechen";
0243 * return null;
0244 * }
0245 *
0246 * protected Set<String> handleKeySet() {
0247 * return new HashSet<String>(Arrays.asList("cancelKey"));
0248 * }
0249 * }
0250 * </pre>
0251 * </blockquote>
0252 * You do not have to restrict yourself to using a single family of
0253 * <code>ResourceBundle</code>s. For example, you could have a set of bundles for
0254 * exception messages, <code>ExceptionResources</code>
0255 * (<code>ExceptionResources_fr</code>, <code>ExceptionResources_de</code>, ...),
0256 * and one for widgets, <code>WidgetResource</code> (<code>WidgetResources_fr</code>,
0257 * <code>WidgetResources_de</code>, ...); breaking up the resources however you like.
0258 *
0259 * @see ListResourceBundle
0260 * @see PropertyResourceBundle
0261 * @see MissingResourceException
0262 * @since JDK1.1
0263 */
0264 public abstract class ResourceBundle {
0265
0266 /** initial size of the bundle cache */
0267 private static final int INITIAL_CACHE_SIZE = 32;
0268
0269 /** constant indicating that no resource bundle exists */
0270 private static final ResourceBundle NONEXISTENT_BUNDLE = new ResourceBundle() {
0271 public Enumeration<String> getKeys() {
0272 return null;
0273 }
0274
0275 protected Object handleGetObject(String key) {
0276 return null;
0277 }
0278
0279 public String toString() {
0280 return "NONEXISTENT_BUNDLE";
0281 }
0282 };
0283
0284 /**
0285 * The cache is a map from cache keys (with bundle base name, locale, and
0286 * class loader) to either a resource bundle or NONEXISTENT_BUNDLE wrapped by a
0287 * BundleReference.
0288 *
0289 * The cache is a ConcurrentMap, allowing the cache to be searched
0290 * concurrently by multiple threads. This will also allow the cache keys
0291 * to be reclaimed along with the ClassLoaders they reference.
0292 *
0293 * This variable would be better named "cache", but we keep the old
0294 * name for compatibility with some workarounds for bug 4212439.
0295 */
0296 private static final ConcurrentMap<CacheKey, BundleReference> cacheList = new ConcurrentHashMap<CacheKey, BundleReference>(
0297 INITIAL_CACHE_SIZE);
0298
0299 /**
0300 * This ConcurrentMap is used to keep multiple threads from loading the
0301 * same bundle concurrently. The table entries are <CacheKey, Thread>
0302 * where CacheKey is the key for the bundle that is under construction
0303 * and Thread is the thread that is constructing the bundle.
0304 * This list is manipulated in findBundleInCache and putBundleInCache.
0305 */
0306 private static final ConcurrentMap<CacheKey, Thread> underConstruction = new ConcurrentHashMap<CacheKey, Thread>();
0307
0308 /**
0309 * Queue for reference objects referring to class loaders or bundles.
0310 */
0311 private static final ReferenceQueue referenceQueue = new ReferenceQueue();
0312
0313 /**
0314 * The parent bundle of this bundle.
0315 * The parent bundle is searched by {@link #getObject getObject}
0316 * when this bundle does not contain a particular resource.
0317 */
0318 protected ResourceBundle parent = null;
0319
0320 /**
0321 * The locale for this bundle.
0322 */
0323 private Locale locale = null;
0324
0325 /**
0326 * The base bundle name for this bundle.
0327 */
0328 private String name;
0329
0330 /**
0331 * The flag indicating this bundle has expired in the cache.
0332 */
0333 private volatile boolean expired;
0334
0335 /**
0336 * The back link to the cache key. null if this bundle isn't in
0337 * the cache (yet) or has expired.
0338 */
0339 private volatile CacheKey cacheKey;
0340
0341 /**
0342 * A Set of the keys contained only in this ResourceBundle.
0343 */
0344 private volatile Set<String> keySet;
0345
0346 /**
0347 * Sole constructor. (For invocation by subclass constructors, typically
0348 * implicit.)
0349 */
0350 public ResourceBundle() {
0351 }
0352
0353 /**
0354 * Gets a string for the given key from this resource bundle or one of its parents.
0355 * Calling this method is equivalent to calling
0356 * <blockquote>
0357 * <code>(String) {@link #getObject(java.lang.String) getObject}(key)</code>.
0358 * </blockquote>
0359 *
0360 * @param key the key for the desired string
0361 * @exception NullPointerException if <code>key</code> is <code>null</code>
0362 * @exception MissingResourceException if no object for the given key can be found
0363 * @exception ClassCastException if the object found for the given key is not a string
0364 * @return the string for the given key
0365 */
0366 public final String getString(String key) {
0367 return (String) getObject(key);
0368 }
0369
0370 /**
0371 * Gets a string array for the given key from this resource bundle or one of its parents.
0372 * Calling this method is equivalent to calling
0373 * <blockquote>
0374 * <code>(String[]) {@link #getObject(java.lang.String) getObject}(key)</code>.
0375 * </blockquote>
0376 *
0377 * @param key the key for the desired string array
0378 * @exception NullPointerException if <code>key</code> is <code>null</code>
0379 * @exception MissingResourceException if no object for the given key can be found
0380 * @exception ClassCastException if the object found for the given key is not a string array
0381 * @return the string array for the given key
0382 */
0383 public final String[] getStringArray(String key) {
0384 return (String[]) getObject(key);
0385 }
0386
0387 /**
0388 * Gets an object for the given key from this resource bundle or one of its parents.
0389 * This method first tries to obtain the object from this resource bundle using
0390 * {@link #handleGetObject(java.lang.String) handleGetObject}.
0391 * If not successful, and the parent resource bundle is not null,
0392 * it calls the parent's <code>getObject</code> method.
0393 * If still not successful, it throws a MissingResourceException.
0394 *
0395 * @param key the key for the desired object
0396 * @exception NullPointerException if <code>key</code> is <code>null</code>
0397 * @exception MissingResourceException if no object for the given key can be found
0398 * @return the object for the given key
0399 */
0400 public final Object getObject(String key) {
0401 Object obj = handleGetObject(key);
0402 if (obj == null) {
0403 if (parent != null) {
0404 obj = parent.getObject(key);
0405 }
0406 if (obj == null)
0407 throw new MissingResourceException(
0408 "Can't find resource for bundle "
0409 + this .getClass().getName() + ", key "
0410 + key, this .getClass().getName(), key);
0411 }
0412 return obj;
0413 }
0414
0415 /**
0416 * Returns the locale of this resource bundle. This method can be used after a
0417 * call to getBundle() to determine whether the resource bundle returned really
0418 * corresponds to the requested locale or is a fallback.
0419 *
0420 * @return the locale of this resource bundle
0421 */
0422 public Locale getLocale() {
0423 return locale;
0424 }
0425
0426 /*
0427 * Automatic determination of the ClassLoader to be used to load
0428 * resources on behalf of the client. N.B. The client is getLoader's
0429 * caller's caller.
0430 */
0431 private static ClassLoader getLoader() {
0432 Class[] stack = getClassContext();
0433 /* Magic number 2 identifies our caller's caller */
0434 Class c = stack[2];
0435 ClassLoader cl = (c == null) ? null : c.getClassLoader();
0436 if (cl == null) {
0437 // When the caller's loader is the boot class loader, cl is null
0438 // here. In that case, ClassLoader.getSystemClassLoader() may
0439 // return the same class loader that the application is
0440 // using. We therefore use a wrapper ClassLoader to create a
0441 // separate scope for bundles loaded on behalf of the Java
0442 // runtime so that these bundles cannot be returned from the
0443 // cache to the application (5048280).
0444 cl = RBClassLoader.INSTANCE;
0445 }
0446 return cl;
0447 }
0448
0449 private static native Class[] getClassContext();
0450
0451 /**
0452 * A wrapper of ClassLoader.getSystemClassLoader().
0453 */
0454 private static class RBClassLoader extends ClassLoader {
0455 private static final RBClassLoader INSTANCE = AccessController
0456 .doPrivileged(new PrivilegedAction<RBClassLoader>() {
0457 public RBClassLoader run() {
0458 return new RBClassLoader();
0459 }
0460 });
0461 private static final ClassLoader loader = ClassLoader
0462 .getSystemClassLoader();
0463
0464 private RBClassLoader() {
0465 }
0466
0467 public Class<?> loadClass(String name)
0468 throws ClassNotFoundException {
0469 if (loader != null) {
0470 return loader.loadClass(name);
0471 }
0472 return Class.forName(name);
0473 }
0474
0475 public URL getResource(String name) {
0476 if (loader != null) {
0477 return loader.getResource(name);
0478 }
0479 return ClassLoader.getSystemResource(name);
0480 }
0481
0482 public InputStream getResourceAsStream(String name) {
0483 if (loader != null) {
0484 return loader.getResourceAsStream(name);
0485 }
0486 return ClassLoader.getSystemResourceAsStream(name);
0487 }
0488 }
0489
0490 /**
0491 * Sets the parent bundle of this bundle.
0492 * The parent bundle is searched by {@link #getObject getObject}
0493 * when this bundle does not contain a particular resource.
0494 *
0495 * @param parent this bundle's parent bundle.
0496 */
0497 protected void setParent(ResourceBundle parent) {
0498 assert parent != NONEXISTENT_BUNDLE;
0499 this .parent = parent;
0500 }
0501
0502 /**
0503 * Key used for cached resource bundles. The key checks the base
0504 * name, the locale, and the class loader to determine if the
0505 * resource is a match to the requested one. The loader may be
0506 * null, but the base name and the locale must have a non-null
0507 * value.
0508 */
0509 private static final class CacheKey implements Cloneable {
0510 // These three are the actual keys for lookup in Map.
0511 private String name;
0512 private Locale locale;
0513 private LoaderReference loaderRef;
0514
0515 // bundle format which is necessary for calling
0516 // Control.needsReload().
0517 private String format;
0518
0519 // These time values are in CacheKey so that NONEXISTENT_BUNDLE
0520 // doesn't need to be cloned for caching.
0521
0522 // The time when the bundle has been loaded
0523 private volatile long loadTime;
0524
0525 // The time when the bundle expires in the cache, or either
0526 // Control.TTL_DONT_CACHE or Control.TTL_NO_EXPIRATION_CONTROL.
0527 private volatile long expirationTime;
0528
0529 // Placeholder for an error report by a Throwable
0530 private Throwable cause;
0531
0532 // Hash code value cache to avoid recalculating the hash code
0533 // of this instance.
0534 private int hashCodeCache;
0535
0536 CacheKey(String baseName, Locale locale, ClassLoader loader) {
0537 this .name = baseName;
0538 this .locale = locale;
0539 if (loader == null) {
0540 this .loaderRef = null;
0541 } else {
0542 loaderRef = new LoaderReference(loader, referenceQueue,
0543 this );
0544 }
0545 calculateHashCode();
0546 }
0547
0548 String getName() {
0549 return name;
0550 }
0551
0552 CacheKey setName(String baseName) {
0553 if (!this .name.equals(baseName)) {
0554 this .name = baseName;
0555 calculateHashCode();
0556 }
0557 return this ;
0558 }
0559
0560 Locale getLocale() {
0561 return locale;
0562 }
0563
0564 CacheKey setLocale(Locale locale) {
0565 if (!this .locale.equals(locale)) {
0566 this .locale = locale;
0567 calculateHashCode();
0568 }
0569 return this ;
0570 }
0571
0572 ClassLoader getLoader() {
0573 return (loaderRef != null) ? loaderRef.get() : null;
0574 }
0575
0576 public boolean equals(Object other) {
0577 if (this == other) {
0578 return true;
0579 }
0580 try {
0581 final CacheKey otherEntry = (CacheKey) other;
0582 //quick check to see if they are not equal
0583 if (hashCodeCache != otherEntry.hashCodeCache) {
0584 return false;
0585 }
0586 //are the names the same?
0587 if (!name.equals(otherEntry.name)) {
0588 return false;
0589 }
0590 // are the locales the same?
0591 if (!locale.equals(otherEntry.locale)) {
0592 return false;
0593 }
0594 //are refs (both non-null) or (both null)?
0595 if (loaderRef == null) {
0596 return otherEntry.loaderRef == null;
0597 }
0598 ClassLoader loader = loaderRef.get();
0599 return (otherEntry.loaderRef != null)
0600 // with a null reference we can no longer find
0601 // out which class loader was referenced; so
0602 // treat it as unequal
0603 && (loader != null)
0604 && (loader == otherEntry.loaderRef.get());
0605 } catch (NullPointerException e) {
0606 } catch (ClassCastException e) {
0607 }
0608 return false;
0609 }
0610
0611 public int hashCode() {
0612 return hashCodeCache;
0613 }
0614
0615 private void calculateHashCode() {
0616 hashCodeCache = name.hashCode() << 3;
0617 hashCodeCache ^= locale.hashCode();
0618 ClassLoader loader = getLoader();
0619 if (loader != null) {
0620 hashCodeCache ^= loader.hashCode();
0621 }
0622 }
0623
0624 public Object clone() {
0625 try {
0626 CacheKey clone = (CacheKey) super .clone();
0627 if (loaderRef != null) {
0628 clone.loaderRef = new LoaderReference(loaderRef
0629 .get(), referenceQueue, clone);
0630 }
0631 // Clear the reference to a Throwable
0632 clone.cause = null;
0633 return clone;
0634 } catch (CloneNotSupportedException e) {
0635 //this should never happen
0636 throw new InternalError();
0637 }
0638 }
0639
0640 String getFormat() {
0641 return format;
0642 }
0643
0644 void setFormat(String format) {
0645 this .format = format;
0646 }
0647
0648 private void setCause(Throwable cause) {
0649 if (this .cause == null) {
0650 this .cause = cause;
0651 } else {
0652 // Override the cause if the previous one is
0653 // ClassNotFoundException.
0654 if (this .cause instanceof ClassNotFoundException) {
0655 this .cause = cause;
0656 }
0657 }
0658 }
0659
0660 private Throwable getCause() {
0661 return cause;
0662 }
0663
0664 public String toString() {
0665 String l = locale.toString();
0666 if (l.length() == 0) {
0667 if (locale.getVariant().length() != 0) {
0668 l = "__" + locale.getVariant();
0669 } else {
0670 l = "\"\"";
0671 }
0672 }
0673 return "CacheKey[" + name + ", lc=" + l + ", ldr="
0674 + getLoader() + "(format=" + format + ")]";
0675 }
0676 }
0677
0678 /**
0679 * The common interface to get a CacheKey in LoaderReference and
0680 * BundleReference.
0681 */
0682 private static interface CacheKeyReference {
0683 public CacheKey getCacheKey();
0684 }
0685
0686 /**
0687 * References to class loaders are weak references, so that they can be
0688 * garbage collected when nobody else is using them. The ResourceBundle
0689 * class has no reason to keep class loaders alive.
0690 */
0691 private static final class LoaderReference extends
0692 WeakReference<ClassLoader> implements CacheKeyReference {
0693 private CacheKey cacheKey;
0694
0695 LoaderReference(ClassLoader referent, ReferenceQueue q,
0696 CacheKey key) {
0697 super (referent, q);
0698 cacheKey = key;
0699 }
0700
0701 public CacheKey getCacheKey() {
0702 return cacheKey;
0703 }
0704 }
0705
0706 /**
0707 * References to bundles are soft references so that they can be garbage
0708 * collected when they have no hard references.
0709 */
0710 private static final class BundleReference extends
0711 SoftReference<ResourceBundle> implements CacheKeyReference {
0712 private CacheKey cacheKey;
0713
0714 BundleReference(ResourceBundle referent, ReferenceQueue q,
0715 CacheKey key) {
0716 super (referent, q);
0717 cacheKey = key;
0718 }
0719
0720 public CacheKey getCacheKey() {
0721 return cacheKey;
0722 }
0723 }
0724
0725 /**
0726 * Gets a resource bundle using the specified base name, the default locale,
0727 * and the caller's class loader. Calling this method is equivalent to calling
0728 * <blockquote>
0729 * <code>getBundle(baseName, Locale.getDefault(), this.getClass().getClassLoader())</code>,
0730 * </blockquote>
0731 * except that <code>getClassLoader()</code> is run with the security
0732 * privileges of <code>ResourceBundle</code>.
0733 * See {@link #getBundle(String, Locale, ClassLoader) getBundle}
0734 * for a complete description of the search and instantiation strategy.
0735 *
0736 * @param baseName the base name of the resource bundle, a fully qualified class name
0737 * @exception java.lang.NullPointerException
0738 * if <code>baseName</code> is <code>null</code>
0739 * @exception MissingResourceException
0740 * if no resource bundle for the specified base name can be found
0741 * @return a resource bundle for the given base name and the default locale
0742 */
0743 public static final ResourceBundle getBundle(String baseName) {
0744 return getBundleImpl(baseName, Locale.getDefault(),
0745 /* must determine loader here, else we break stack invariant */
0746 getLoader(), Control.INSTANCE);
0747 }
0748
0749 /**
0750 * Returns a resource bundle using the specified base name, the
0751 * default locale and the specified control. Calling this method
0752 * is equivalent to calling
0753 * <pre>
0754 * getBundle(baseName, Locale.getDefault(),
0755 * this.getClass().getClassLoader(), control),
0756 * </pre>
0757 * except that <code>getClassLoader()</code> is run with the security
0758 * privileges of <code>ResourceBundle</code>. See {@link
0759 * #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
0760 * complete description of the resource bundle loading process with a
0761 * <code>ResourceBundle.Control</code>.
0762 *
0763 * @param baseName
0764 * the base name of the resource bundle, a fully qualified class
0765 * name
0766 * @param control
0767 * the control which gives information for the resource bundle
0768 * loading process
0769 * @return a resource bundle for the given base name and the default
0770 * locale
0771 * @exception NullPointerException
0772 * if <code>baseName</code> or <code>control</code> is
0773 * <code>null</code>
0774 * @exception MissingResourceException
0775 * if no resource bundle for the specified base name can be found
0776 * @exception IllegalArgumentException
0777 * if the given <code>control</code> doesn't perform properly
0778 * (e.g., <code>control.getCandidateLocales</code> returns null.)
0779 * Note that validation of <code>control</code> is performed as
0780 * needed.
0781 * @since 1.6
0782 */
0783 public static final ResourceBundle getBundle(String baseName,
0784 Control control) {
0785 return getBundleImpl(baseName, Locale.getDefault(),
0786 /* must determine loader here, else we break stack invariant */
0787 getLoader(), control);
0788 }
0789
0790 /**
0791 * Gets a resource bundle using the specified base name and locale,
0792 * and the caller's class loader. Calling this method is equivalent to calling
0793 * <blockquote>
0794 * <code>getBundle(baseName, locale, this.getClass().getClassLoader())</code>,
0795 * </blockquote>
0796 * except that <code>getClassLoader()</code> is run with the security
0797 * privileges of <code>ResourceBundle</code>.
0798 * See {@link #getBundle(String, Locale, ClassLoader) getBundle}
0799 * for a complete description of the search and instantiation strategy.
0800 *
0801 * @param baseName
0802 * the base name of the resource bundle, a fully qualified class name
0803 * @param locale
0804 * the locale for which a resource bundle is desired
0805 * @exception NullPointerException
0806 * if <code>baseName</code> or <code>locale</code> is <code>null</code>
0807 * @exception MissingResourceException
0808 * if no resource bundle for the specified base name can be found
0809 * @return a resource bundle for the given base name and locale
0810 */
0811 public static final ResourceBundle getBundle(String baseName,
0812 Locale locale) {
0813 return getBundleImpl(baseName, locale,
0814 /* must determine loader here, else we break stack invariant */
0815 getLoader(), Control.INSTANCE);
0816 }
0817
0818 /**
0819 * Returns a resource bundle using the specified base name, target
0820 * locale and control, and the caller's class loader. Calling this
0821 * method is equivalent to calling
0822 * <pre>
0823 * getBundle(baseName, targetLocale, this.getClass().getClassLoader(),
0824 * control),
0825 * </pre>
0826 * except that <code>getClassLoader()</code> is run with the security
0827 * privileges of <code>ResourceBundle</code>. See {@link
0828 * #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
0829 * complete description of the resource bundle loading process with a
0830 * <code>ResourceBundle.Control</code>.
0831 *
0832 * @param baseName
0833 * the base name of the resource bundle, a fully qualified
0834 * class name
0835 * @param targetLocale
0836 * the locale for which a resource bundle is desired
0837 * @param control
0838 * the control which gives information for the resource
0839 * bundle loading process
0840 * @return a resource bundle for the given base name and a
0841 * <code>Locale</code> in <code>locales</code>
0842 * @exception NullPointerException
0843 * if <code>baseName</code>, <code>locales</code> or
0844 * <code>control</code> is <code>null</code>
0845 * @exception MissingResourceException
0846 * if no resource bundle for the specified base name in any
0847 * of the <code>locales</code> can be found.
0848 * @exception IllegalArgumentException
0849 * if the given <code>control</code> doesn't perform properly
0850 * (e.g., <code>control.getCandidateLocales</code> returns null.)
0851 * Note that validation of <code>control</code> is performed as
0852 * needed.
0853 * @since 1.6
0854 */
0855 public static final ResourceBundle getBundle(String baseName,
0856 Locale targetLocale, Control control) {
0857 return getBundleImpl(baseName, targetLocale,
0858 /* must determine loader here, else we break stack invariant */
0859 getLoader(), control);
0860 }
0861
0862 /**
0863 * Gets a resource bundle using the specified base name, locale, and class loader.
0864 *
0865 * <p><a name="default_behavior"/>
0866 * Conceptually, <code>getBundle</code> uses the following strategy for locating and instantiating
0867 * resource bundles:
0868 * <p>
0869 * <code>getBundle</code> uses the base name, the specified locale, and the default
0870 * locale (obtained from {@link java.util.Locale#getDefault() Locale.getDefault})
0871 * to generate a sequence of <a name="candidates"><em>candidate bundle names</em></a>.
0872 * If the specified locale's language, country, and variant are all empty
0873 * strings, then the base name is the only candidate bundle name.
0874 * Otherwise, the following sequence is generated from the attribute
0875 * values of the specified locale (language1, country1, and variant1)
0876 * and of the default locale (language2, country2, and variant2):
0877 * <ul>
0878 * <li> baseName + "_" + language1 + "_" + country1 + "_" + variant1
0879 * <li> baseName + "_" + language1 + "_" + country1
0880 * <li> baseName + "_" + language1
0881 * <li> baseName + "_" + language2 + "_" + country2 + "_" + variant2
0882 * <li> baseName + "_" + language2 + "_" + country2
0883 * <li> baseName + "_" + language2
0884 * <li> baseName
0885 * </ul>
0886 * <p>
0887 * Candidate bundle names where the final component is an empty string are omitted.
0888 * For example, if country1 is an empty string, the second candidate bundle name is omitted.
0889 *
0890 * <p>
0891 * <code>getBundle</code> then iterates over the candidate bundle names to find the first
0892 * one for which it can <em>instantiate</em> an actual resource bundle. For each candidate
0893 * bundle name, it attempts to create a resource bundle:
0894 * <ul>
0895 * <li>
0896 * First, it attempts to load a class using the candidate bundle name.
0897 * If such a class can be found and loaded using the specified class loader, is assignment
0898 * compatible with ResourceBundle, is accessible from ResourceBundle, and can be instantiated,
0899 * <code>getBundle</code> creates a new instance of this class and uses it as the <em>result
0900 * resource bundle</em>.
0901 * <li>
0902 * Otherwise, <code>getBundle</code> attempts to locate a property resource file.
0903 * It generates a path name from the candidate bundle name by replacing all "." characters
0904 * with "/" and appending the string ".properties".
0905 * It attempts to find a "resource" with this name using
0906 * {@link java.lang.ClassLoader#getResource(java.lang.String) ClassLoader.getResource}.
0907 * (Note that a "resource" in the sense of <code>getResource</code> has nothing to do with
0908 * the contents of a resource bundle, it is just a container of data, such as a file.)
0909 * If it finds a "resource", it attempts to create a new
0910 * {@link PropertyResourceBundle} instance from its contents.
0911 * If successful, this instance becomes the <em>result resource bundle</em>.
0912 * </ul>
0913 *
0914 * <p>
0915 * If no result resource bundle has been found, a <code>MissingResourceException</code>
0916 * is thrown.
0917 *
0918 * <p><a name="parent_chain"/>
0919 * Once a result resource bundle has been found, its <em>parent chain</em> is instantiated.
0920 * <code>getBundle</code> iterates over the candidate bundle names that can be
0921 * obtained by successively removing variant, country, and language
0922 * (each time with the preceding "_") from the bundle name of the result resource bundle.
0923 * As above, candidate bundle names where the final component is an empty string are omitted.
0924 * With each of the candidate bundle names it attempts to instantiate a resource bundle, as
0925 * described above.
0926 * Whenever it succeeds, it calls the previously instantiated resource
0927 * bundle's {@link #setParent(java.util.ResourceBundle) setParent} method
0928 * with the new resource bundle, unless the previously instantiated resource
0929 * bundle already has a non-null parent.
0930 *
0931 * <p>
0932 * <code>getBundle</code> caches instantiated resource bundles and
0933 * may return the same resource bundle instance multiple
0934 * times.
0935 *
0936 * <p>
0937 * The <code>baseName</code> argument should be a fully qualified class name. However, for
0938 * compatibility with earlier versions, Sun's Java SE Runtime Environments do not verify this,
0939 * and so it is possible to access <code>PropertyResourceBundle</code>s by specifying a
0940 * path name (using "/") instead of a fully qualified class name (using ".").
0941 *
0942 * <p><a name="default_behavior_example"/>
0943 * <strong>Example:</strong><br>The following class and property files are provided:
0944 * <pre>
0945 * MyResources.class
0946 * MyResources.properties
0947 * MyResources_fr.properties
0948 * MyResources_fr_CH.class
0949 * MyResources_fr_CH.properties
0950 * MyResources_en.properties
0951 * MyResources_es_ES.class
0952 * </pre>
0953 * The contents of all files are valid (that is, public non-abstract subclasses of <code>ResourceBundle</code> for
0954 * the ".class" files, syntactically correct ".properties" files).
0955 * The default locale is <code>Locale("en", "GB")</code>.
0956 * <p>
0957 * Calling <code>getBundle</code> with the shown locale argument values instantiates
0958 * resource bundles from the following sources:
0959 * <ul>
0960 * <li>Locale("fr", "CH"): result MyResources_fr_CH.class, parent MyResources_fr.properties, parent MyResources.class
0961 * <li>Locale("fr", "FR"): result MyResources_fr.properties, parent MyResources.class
0962 * <li>Locale("de", "DE"): result MyResources_en.properties, parent MyResources.class
0963 * <li>Locale("en", "US"): result MyResources_en.properties, parent MyResources.class
0964 * <li>Locale("es", "ES"): result MyResources_es_ES.class, parent MyResources.class
0965 * </ul>
0966 * <p>The file MyResources_fr_CH.properties is never used because it is hidden by
0967 * MyResources_fr_CH.class. Likewise, MyResources.properties is also hidden by
0968 * MyResources.class.
0969 *
0970 * @param baseName the base name of the resource bundle, a fully qualified class name
0971 * @param locale the locale for which a resource bundle is desired
0972 * @param loader the class loader from which to load the resource bundle
0973 * @return a resource bundle for the given base name and locale
0974 * @exception java.lang.NullPointerException
0975 * if <code>baseName</code>, <code>locale</code>, or <code>loader</code> is <code>null</code>
0976 * @exception MissingResourceException
0977 * if no resource bundle for the specified base name can be found
0978 * @since 1.2
0979 */
0980 public static ResourceBundle getBundle(String baseName,
0981 Locale locale, ClassLoader loader) {
0982 if (loader == null) {
0983 throw new NullPointerException();
0984 }
0985 return getBundleImpl(baseName, locale, loader, Control.INSTANCE);
0986 }
0987
0988 /**
0989 * Returns a resource bundle using the specified base name, target
0990 * locale, class loader and control. Unlike the {@linkplain
0991 * #getBundle(String, Locale, ClassLoader) <code>getBundle</code>
0992 * factory methods with no <code>control</code> argument}, the given
0993 * <code>control</code> specifies how to locate and instantiate resource
0994 * bundles. Conceptually, the bundle loading process with the given
0995 * <code>control</code> is performed in the following steps.
0996 *
0997 * <p>
0998 * <ol>
0999 * <li>This factory method looks up the resource bundle in the cache for
1000 * the specified <code>baseName</code>, <code>targetLocale</code> and
1001 * <code>loader</code>. If the requested resource bundle instance is
1002 * found in the cache and the time-to-live periods of the instance and
1003 * all of its parent instances have not expired, the instance is returned
1004 * to the caller. Otherwise, this factory method proceeds with the
1005 * loading process below.</li>
1006 *
1007 * <li>The {@link ResourceBundle.Control#getFormats(String)
1008 * control.getFormats} method is called to get resource bundle formats
1009 * to produce bundle or resource names. The strings
1010 * <code>"java.class"</code> and <code>"java.properties"</code>
1011 * designate class-based and {@linkplain PropertyResourceBundle
1012 * property}-based resource bundles, respectively. Other strings
1013 * starting with <code>"java."</code> are reserved for future extensions
1014 * and must not be used for application-defined formats. Other strings
1015 * designate application-defined formats.</li>
1016 *
1017 * <li>The {@link ResourceBundle.Control#getCandidateLocales(String,
1018 * Locale) control.getCandidateLocales} method is called with the target
1019 * locale to get a list of <em>candidate <code>Locale</code>s</em> for
1020 * which resource bundles are searched.</li>
1021 *
1022 * <li>The {@link ResourceBundle.Control#newBundle(String, Locale,
1023 * String, ClassLoader, boolean) control.newBundle} method is called to
1024 * instantiate a <code>ResourceBundle</code> for the base bundle name, a
1025 * candidate locale, and a format. (Refer to the note on the cache
1026 * lookup below.) This step is iterated over all combinations of the
1027 * candidate locales and formats until the <code>newBundle</code> method
1028 * returns a <code>ResourceBundle</code> instance or the iteration has
1029 * used up all the combinations. For example, if the candidate locales
1030 * are <code>Locale("de", "DE")</code>, <code>Locale("de")</code> and
1031 * <code>Locale("")</code> and the formats are <code>"java.class"</code>
1032 * and <code>"java.properties"</code>, then the following is the
1033 * sequence of locale-format combinations to be used to call
1034 * <code>control.newBundle</code>.
1035 *
1036 * <table style="width: 50%; text-align: left; margin-left: 40px;"
1037 * border="0" cellpadding="2" cellspacing="2">
1038 * <tbody><code>
1039 * <tr>
1040 * <td
1041 * style="vertical-align: top; text-align: left; font-weight: bold; width: 50%;">Locale<br>
1042 * </td>
1043 * <td
1044 * style="vertical-align: top; text-align: left; font-weight: bold; width: 50%;">format<br>
1045 * </td>
1046 * </tr>
1047 * <tr>
1048 * <td style="vertical-align: top; width: 50%;">Locale("de", "DE")<br>
1049 * </td>
1050 * <td style="vertical-align: top; width: 50%;">java.class<br>
1051 * </td>
1052 * </tr>
1053 * <tr>
1054 * <td style="vertical-align: top; width: 50%;">Locale("de", "DE")</td>
1055 * <td style="vertical-align: top; width: 50%;">java.properties<br>
1056 * </td>
1057 * </tr>
1058 * <tr>
1059 * <td style="vertical-align: top; width: 50%;">Locale("de")</td>
1060 * <td style="vertical-align: top; width: 50%;">java.class</td>
1061 * </tr>
1062 * <tr>
1063 * <td style="vertical-align: top; width: 50%;">Locale("de")</td>
1064 * <td style="vertical-align: top; width: 50%;">java.properties</td>
1065 * </tr>
1066 * <tr>
1067 * <td style="vertical-align: top; width: 50%;">Locale("")<br>
1068 * </td>
1069 * <td style="vertical-align: top; width: 50%;">java.class</td>
1070 * </tr>
1071 * <tr>
1072 * <td style="vertical-align: top; width: 50%;">Locale("")</td>
1073 * <td style="vertical-align: top; width: 50%;">java.properties</td>
1074 * </tr>
1075 * </code></tbody>
1076 * </table>
1077 * </li>
1078 *
1079 * <li>If the previous step has found no resource bundle, proceed to
1080 * Step 6. If a bundle has been found that is a base bundle (a bundle
1081 * for <code>Locale("")</code>), and the candidate locale list only contained
1082 * <code>Locale("")</code>, return the bundle to the caller. If a bundle
1083 * has been found that is a base bundle, but the candidate locale list
1084 * contained locales other than Locale(""), put the bundle on hold and
1085 * proceed to Step 6. If a bundle has been found that is not a base
1086 * bundle, proceed to Step 7.</li>
1087 *
1088 * <li>The {@link ResourceBundle.Control#getFallbackLocale(String,
1089 * Locale) control.getFallbackLocale} method is called to get a fallback
1090 * locale (alternative to the current target locale) to try further
1091 * finding a resource bundle. If the method returns a non-null locale,
1092 * it becomes the next target locale and the loading process starts over
1093 * from Step 3. Otherwise, if a base bundle was found and put on hold in
1094 * a previous Step 5, it is returned to the caller now. Otherwise, a
1095 * MissingResourceException is thrown.</li>
1096 *
1097 * <li>At this point, we have found a resource bundle that's not the
1098 * base bundle. If this bundle set its parent during its instantiation,
1099 * it is returned to the caller. Otherwise, its <a
1100 * href="./ResourceBundle.html#parent_chain">parent chain</a> is
1101 * instantiated based on the list of candidate locales from which it was
1102 * found. Finally, the bundle is returned to the caller.</li>
1103 *
1104 *
1105 * </ol>
1106 *
1107 * <p>During the resource bundle loading process above, this factory
1108 * method looks up the cache before calling the {@link
1109 * Control#newBundle(String, Locale, String, ClassLoader, boolean)
1110 * control.newBundle} method. If the time-to-live period of the
1111 * resource bundle found in the cache has expired, the factory method
1112 * calls the {@link ResourceBundle.Control#needsReload(String, Locale,
1113 * String, ClassLoader, ResourceBundle, long) control.needsReload}
1114 * method to determine whether the resource bundle needs to be reloaded.
1115 * If reloading is required, the factory method calls
1116 * <code>control.newBundle</code> to reload the resource bundle. If
1117 * <code>control.newBundle</code> returns <code>null</code>, the factory
1118 * method puts a dummy resource bundle in the cache as a mark of
1119 * nonexistent resource bundles in order to avoid lookup overhead for
1120 * subsequent requests. Such dummy resource bundles are under the same
1121 * expiration control as specified by <code>control</code>.
1122 *
1123 * <p>All resource bundles loaded are cached by default. Refer to
1124 * {@link Control#getTimeToLive(String,Locale)
1125 * control.getTimeToLive} for details.
1126 *
1127 *
1128 * <p>The following is an example of the bundle loading process with the
1129 * default <code>ResourceBundle.Control</code> implementation.
1130 *
1131 * <p>Conditions:
1132 * <ul>
1133 * <li>Base bundle name: <code>foo.bar.Messages</code>
1134 * <li>Requested <code>Locale</code>: {@link Locale#ITALY}</li>
1135 * <li>Default <code>Locale</code>: {@link Locale#FRENCH}</li>
1136 * <li>Available resource bundles:
1137 * <code>foo/bar/Messages_fr.properties</code> and
1138 * <code>foo/bar/Messages.properties</code></li>
1139 *
1140 * </ul>
1141 *
1142 * <p>First, <code>getBundle</code> tries loading a resource bundle in
1143 * the following sequence.
1144 *
1145 * <ul>
1146 * <li>class <code>foo.bar.Messages_it_IT</code>
1147 * <li>file <code>foo/bar/Messages_it_IT.properties</code>
1148 * <li>class <code>foo.bar.Messages_it</code></li>
1149 * <li>file <code>foo/bar/Messages_it.properties</code></li>
1150 * <li>class <code>foo.bar.Messages</code></li>
1151 * <li>file <code>foo/bar/Messages.properties</code></li>
1152 * </ul>
1153 *
1154 * <p>At this point, <code>getBundle</code> finds
1155 * <code>foo/bar/Messages.properties</code>, which is put on hold
1156 * because it's the base bundle. <code>getBundle</code> calls {@link
1157 * Control#getFallbackLocale(String, Locale)
1158 * control.getFallbackLocale("foo.bar.Messages", Locale.ITALY)} which
1159 * returns <code>Locale.FRENCH</code>. Next, <code>getBundle</code>
1160 * tries loading a bundle in the following sequence.
1161 *
1162 * <ul>
1163 * <li>class <code>foo.bar.Messages_fr</code></li>
1164 * <li>file <code>foo/bar/Messages_fr.properties</code></li>
1165 * <li>class <code>foo.bar.Messages</code></li>
1166 * <li>file <code>foo/bar/Messages.properties</code></li>
1167 * </ul>
1168 *
1169 * <p><code>getBundle</code> finds
1170 * <code>foo/bar/Messages_fr.properties</code> and creates a
1171 * <code>ResourceBundle</code> instance. Then, <code>getBundle</code>
1172 * sets up its parent chain from the list of the candiate locales. Only
1173 * <code>foo/bar/Messages.properties</code> is found in the list and
1174 * <code>getBundle</code> creates a <code>ResourceBundle</code> instance
1175 * that becomes the parent of the instance for
1176 * <code>foo/bar/Messages_fr.properties</code>.
1177 *
1178 * @param baseName
1179 * the base name of the resource bundle, a fully qualified
1180 * class name
1181 * @param targetLocale
1182 * the locale for which a resource bundle is desired
1183 * @param loader
1184 * the class loader from which to load the resource bundle
1185 * @param control
1186 * the control which gives information for the resource
1187 * bundle loading process
1188 * @return a resource bundle for the given base name and locale
1189 * @exception NullPointerException
1190 * if <code>baseName</code>, <code>targetLocale</code>,
1191 * <code>loader</code>, or <code>control</code> is
1192 * <code>null</code>
1193 * @exception MissingResourceException
1194 * if no resource bundle for the specified base name can be found
1195 * @exception IllegalArgumentException
1196 * if the given <code>control</code> doesn't perform properly
1197 * (e.g., <code>control.getCandidateLocales</code> returns null.)
1198 * Note that validation of <code>control</code> is performed as
1199 * needed.
1200 * @since 1.6
1201 */
1202 public static ResourceBundle getBundle(String baseName,
1203 Locale targetLocale, ClassLoader loader, Control control) {
1204 if (loader == null || control == null) {
1205 throw new NullPointerException();
1206 }
1207 return getBundleImpl(baseName, targetLocale, loader, control);
1208 }
1209
1210 private static ResourceBundle getBundleImpl(String baseName,
1211 Locale locale, ClassLoader loader, Control control) {
1212 if (locale == null || control == null) {
1213 throw new NullPointerException();
1214 }
1215
1216 // We create a CacheKey here for use by this call. The base
1217 // name and loader will never change during the bundle loading
1218 // process. We have to make sure that the locale is set before
1219 // using it as a cache key.
1220 CacheKey cacheKey = new CacheKey(baseName, locale, loader);
1221 ResourceBundle bundle = null;
1222
1223 // Quick lookup of the cache.
1224 BundleReference bundleRef = cacheList.get(cacheKey);
1225 if (bundleRef != null) {
1226 bundle = bundleRef.get();
1227 bundleRef = null;
1228 }
1229
1230 // If this bundle and all of its parents are valid (not expired),
1231 // then return this bundle. If any of the bundles is expired, we
1232 // don't call control.needsReload here but instead drop into the
1233 // complete loading process below.
1234 if (isValidBundle(bundle) && hasValidParentChain(bundle)) {
1235 return bundle;
1236 }
1237
1238 // No valid bundle was found in the cache, so we need to load the
1239 // resource bundle and its parents.
1240
1241 boolean isKnownControl = (control == Control.INSTANCE)
1242 || (control instanceof SingleFormatControl);
1243 List<String> formats = control.getFormats(baseName);
1244 if (!isKnownControl && !checkList(formats)) {
1245 throw new IllegalArgumentException(
1246 "Invalid Control: getFormats");
1247 }
1248
1249 ResourceBundle baseBundle = null;
1250 for (Locale targetLocale = locale; targetLocale != null; targetLocale = control
1251 .getFallbackLocale(baseName, targetLocale)) {
1252 List<Locale> candidateLocales = control
1253 .getCandidateLocales(baseName, targetLocale);
1254 if (!isKnownControl && !checkList(candidateLocales)) {
1255 throw new IllegalArgumentException(
1256 "Invalid Control: getCandidateLocales");
1257 }
1258
1259 bundle = findBundle(cacheKey, candidateLocales, formats, 0,
1260 control, baseBundle);
1261
1262 // If the loaded bundle is the base bundle and exactly for the
1263 // requested locale or the only candidate locale, then take the
1264 // bundle as the resulting one. If the loaded bundle is the base
1265 // bundle, it's put on hold until we finish processing all
1266 // fallback locales.
1267 if (isValidBundle(bundle)) {
1268 boolean isBaseBundle = Locale.ROOT
1269 .equals(bundle.locale);
1270 if (!isBaseBundle
1271 || bundle.locale.equals(locale)
1272 || (candidateLocales.size() == 1 && bundle.locale
1273 .equals(candidateLocales.get(0)))) {
1274 break;
1275 }
1276
1277 // If the base bundle has been loaded, keep the reference in
1278 // baseBundle so that we can avoid any redundant loading in case
1279 // the control specify not to cache bundles.
1280 if (isBaseBundle && baseBundle == null) {
1281 baseBundle = bundle;
1282 }
1283 }
1284 }
1285
1286 if (bundle == null) {
1287 if (baseBundle == null) {
1288 throwMissingResourceException(baseName, locale,
1289 cacheKey.getCause());
1290 }
1291 bundle = baseBundle;
1292 }
1293
1294 return bundle;
1295 }
1296
1297 /**
1298 * Checks if the given <code>List</code> is not null, not empty,
1299 * not having null in its elements.
1300 */
1301 private static final boolean checkList(List a) {
1302 boolean valid = (a != null && a.size() != 0);
1303 if (valid) {
1304 int size = a.size();
1305 for (int i = 0; valid && i < size; i++) {
1306 valid = (a.get(i) != null);
1307 }
1308 }
1309 return valid;
1310 }
1311
1312 private static final ResourceBundle findBundle(CacheKey cacheKey,
1313 List<Locale> candidateLocales, List<String> formats,
1314 int index, Control control, ResourceBundle baseBundle) {
1315 Locale targetLocale = candidateLocales.get(index);
1316 ResourceBundle parent = null;
1317 if (index != candidateLocales.size() - 1) {
1318 parent = findBundle(cacheKey, candidateLocales, formats,
1319 index + 1, control, baseBundle);
1320 } else if (baseBundle != null
1321 && Locale.ROOT.equals(targetLocale)) {
1322 return baseBundle;
1323 }
1324
1325 // Before we do the real loading work, see whether we need to
1326 // do some housekeeping: If references to class loaders or
1327 // resource bundles have been nulled out, remove all related
1328 // information from the cache.
1329 Object ref;
1330 while ((ref = referenceQueue.poll()) != null) {
1331 cacheList.remove(((CacheKeyReference) ref).getCacheKey());
1332 }
1333
1334 // flag indicating the resource bundle has expired in the cache
1335 boolean expiredBundle = false;
1336
1337 // First, look up the cache to see if it's in the cache, without
1338 // declaring beginLoading.
1339 cacheKey.setLocale(targetLocale);
1340 ResourceBundle bundle = findBundleInCache(cacheKey, control);
1341 if (isValidBundle(bundle)) {
1342 expiredBundle = bundle.expired;
1343 if (!expiredBundle) {
1344 // If its parent is the one asked for by the candidate
1345 // locales (the runtime lookup path), we can take the cached
1346 // one. (If it's not identical, then we'd have to check the
1347 // parent's parents to be consistent with what's been
1348 // requested.)
1349 if (bundle.parent == parent) {
1350 return bundle;
1351 }
1352 // Otherwise, remove the cached one since we can't keep
1353 // the same bundles having different parents.
1354 BundleReference bundleRef = cacheList.get(cacheKey);
1355 if (bundleRef != null && bundleRef.get() == bundle) {
1356 cacheList.remove(cacheKey, bundleRef);
1357 }
1358 }
1359 }
1360
1361 if (bundle != NONEXISTENT_BUNDLE) {
1362 CacheKey constKey = (CacheKey) cacheKey.clone();
1363
1364 try {
1365 // Try declaring loading. If beginLoading() returns true,
1366 // then we can proceed. Otherwise, we need to take a look
1367 // at the cache again to see if someone else has loaded
1368 // the bundle and put it in the cache while we've been
1369 // waiting for other loading work to complete.
1370 while (!beginLoading(constKey)) {
1371 bundle = findBundleInCache(cacheKey, control);
1372 if (bundle == null) {
1373 continue;
1374 }
1375 if (bundle == NONEXISTENT_BUNDLE) {
1376 // If the bundle is NONEXISTENT_BUNDLE, the bundle doesn't exist.
1377 return parent;
1378 }
1379 expiredBundle = bundle.expired;
1380 if (!expiredBundle) {
1381 if (bundle.parent == parent) {
1382 return bundle;
1383 }
1384 BundleReference bundleRef = cacheList
1385 .get(cacheKey);
1386 if (bundleRef != null
1387 && bundleRef.get() == bundle) {
1388 cacheList.remove(cacheKey, bundleRef);
1389 }
1390 }
1391 }
1392
1393 try {
1394 bundle = loadBundle(cacheKey, formats, control,
1395 expiredBundle);
1396 if (bundle != null) {
1397 if (bundle.parent == null) {
1398 bundle.setParent(parent);
1399 }
1400 bundle.locale = targetLocale;
1401 bundle = putBundleInCache(cacheKey, bundle,
1402 control);
1403 return bundle;
1404 }
1405
1406 // Put NONEXISTENT_BUNDLE in the cache as a mark that there's no bundle
1407 // instance for the locale.
1408 putBundleInCache(cacheKey, NONEXISTENT_BUNDLE,
1409 control);
1410 } finally {
1411 endLoading(constKey);
1412 }
1413 } finally {
1414 if (constKey.getCause() instanceof InterruptedException) {
1415 Thread.currentThread().interrupt();
1416 }
1417 }
1418 }
1419 assert underConstruction.get(cacheKey) != Thread
1420 .currentThread();
1421 return parent;
1422 }
1423
1424 private static final ResourceBundle loadBundle(CacheKey cacheKey,
1425 List<String> formats, Control control, boolean reload) {
1426 assert underConstruction.get(cacheKey) == Thread
1427 .currentThread();
1428
1429 // Here we actually load the bundle in the order of formats
1430 // specified by the getFormats() value.
1431 Locale targetLocale = cacheKey.getLocale();
1432
1433 ResourceBundle bundle = null;
1434 int size = formats.size();
1435 for (int i = 0; i < size; i++) {
1436 String format = formats.get(i);
1437 try {
1438 bundle = control.newBundle(cacheKey.getName(),
1439 targetLocale, format, cacheKey.getLoader(),
1440 reload);
1441 } catch (LinkageError error) {
1442 // We need to handle the LinkageError case due to
1443 // inconsistent case-sensitivity in ClassLoader.
1444 // See 6572242 for details.
1445 cacheKey.setCause(error);
1446 } catch (Exception cause) {
1447 cacheKey.setCause(cause);
1448 }
1449 if (bundle != null) {
1450 // Set the format in the cache key so that it can be
1451 // used when calling needsReload later.
1452 cacheKey.setFormat(format);
1453 bundle.name = cacheKey.getName();
1454 bundle.locale = targetLocale;
1455 // Bundle provider might reuse instances. So we should make
1456 // sure to clear the expired flag here.
1457 bundle.expired = false;
1458 break;
1459 }
1460 }
1461 assert underConstruction.get(cacheKey) == Thread
1462 .currentThread();
1463
1464 return bundle;
1465 }
1466
1467 private static final boolean isValidBundle(ResourceBundle bundle) {
1468 return bundle != null && bundle != NONEXISTENT_BUNDLE;
1469 }
1470
1471 /**
1472 * Determines whether any of resource bundles in the parent chain,
1473 * including the leaf, have expired.
1474 */
1475 private static final boolean hasValidParentChain(
1476 ResourceBundle bundle) {
1477 long now = System.currentTimeMillis();
1478 while (bundle != null) {
1479 if (bundle.expired) {
1480 return false;
1481 }
1482 CacheKey key = bundle.cacheKey;
1483 if (key != null) {
1484 long expirationTime = key.expirationTime;
1485 if (expirationTime >= 0 && expirationTime <= now) {
1486 return false;
1487 }
1488 }
1489 bundle = bundle.parent;
1490 }
1491 return true;
1492 }
1493
1494 /**
1495 * Declares the beginning of actual resource bundle loading. This method
1496 * returns true if the declaration is successful and the current thread has
1497 * been put in underConstruction. If someone else has already begun
1498 * loading, this method waits until that loading work is complete and
1499 * returns false.
1500 */
1501 private static final boolean beginLoading(CacheKey constKey) {
1502 Thread me = Thread.currentThread();
1503 Thread worker;
1504 // We need to declare by putting the current Thread (me) to
1505 // underConstruction that we are working on loading the specified
1506 // resource bundle. If we are already working the loading, it means
1507 // that the resource loading requires a recursive call. In that case,
1508 // we have to proceed. (4300693)
1509 if (((worker = underConstruction.putIfAbsent(constKey, me)) == null)
1510 || worker == me) {
1511 return true;
1512 }
1513
1514 // If someone else is working on the loading, wait until
1515 // the Thread finishes the bundle loading.
1516 synchronized (worker) {
1517 while (underConstruction.get(constKey) == worker) {
1518 try {
1519 worker.wait();
1520 } catch (InterruptedException e) {
1521 // record the interruption
1522 constKey.setCause(e);
1523 }
1524 }
1525 }
1526 return false;
1527 }
1528
1529 /**
1530 * Declares the end of the bundle loading. This method calls notifyAll
1531 * for those who are waiting for this completion.
1532 */
1533 private static final void endLoading(CacheKey constKey) {
1534 // Remove this Thread from the underConstruction map and wake up
1535 // those who have been waiting for me to complete this bundle
1536 // loading.
1537 Thread me = Thread.currentThread();
1538 assert (underConstruction.get(constKey) == me);
1539 underConstruction.remove(constKey);
1540 synchronized (me) {
1541 me.notifyAll();
1542 }
1543 }
1544
1545 /**
1546 * Throw a MissingResourceException with proper message
1547 */
1548 private static final void throwMissingResourceException(
1549 String baseName, Locale locale, Throwable cause) {
1550 // If the cause is a MissingResourceException, avoid creating
1551 // a long chain. (6355009)
1552 if (cause instanceof MissingResourceException) {
1553 cause = null;
1554 }
1555 throw new MissingResourceException(
1556 "Can't find bundle for base name " + baseName
1557 + ", locale " + locale,
1558 baseName + "_" + locale, // className
1559 "", // key
1560 cause);
1561 }
1562
1563 /**
1564 * Finds a bundle in the cache. Any expired bundles are marked as
1565 * `expired' and removed from the cache upon return.
1566 *
1567 * @param cacheKey the key to look up the cache
1568 * @param control the Control to be used for the expiration control
1569 * @return the cached bundle, or null if the bundle is not found in the
1570 * cache or its parent has expired. <code>bundle.expire</code> is true
1571 * upon return if the bundle in the cache has expired.
1572 */
1573 private static final ResourceBundle findBundleInCache(
1574 CacheKey cacheKey, Control control) {
1575 BundleReference bundleRef = cacheList.get(cacheKey);
1576 if (bundleRef == null) {
1577 return null;
1578 }
1579 ResourceBundle bundle = bundleRef.get();
1580 if (bundle == null) {
1581 return null;
1582 }
1583 ResourceBundle p = bundle.parent;
1584 assert p != NONEXISTENT_BUNDLE;
1585 // If the parent has expired, then this one must also expire. We
1586 // check only the immediate parent because the actual loading is
1587 // done from the root (base) to leaf (child) and the purpose of
1588 // checking is to propagate expiration towards the leaf. For
1589 // example, if the requested locale is ja_JP_JP and there are
1590 // bundles for all of the candidates in the cache, we have a list,
1591 //
1592 // base <- ja <- ja_JP <- ja_JP_JP
1593 //
1594 // If ja has expired, then it will reload ja and the list becomes a
1595 // tree.
1596 //
1597 // base <- ja (new)
1598 // " <- ja (expired) <- ja_JP <- ja_JP_JP
1599 //
1600 // When looking up ja_JP in the cache, it finds ja_JP in the cache
1601 // which references to the expired ja. Then, ja_JP is marked as
1602 // expired and removed from the cache. This will be propagated to
1603 // ja_JP_JP.
1604 //
1605 // Now, it's possible, for example, that while loading new ja_JP,
1606 // someone else has started loading the same bundle and finds the
1607 // base bundle has expired. Then, what we get from the first
1608 // getBundle call includes the expired base bundle. However, if
1609 // someone else didn't start its loading, we wouldn't know if the
1610 // base bundle has expired at the end of the loading process. The
1611 // expiration control doesn't guarantee that the returned bundle and
1612 // its parents haven't expired.
1613 //
1614 // We could check the entire parent chain to see if there's any in
1615 // the chain that has expired. But this process may never end. An
1616 // extreme case would be that getTimeToLive returns 0 and
1617 // needsReload always returns true.
1618 if (p != null && p.expired) {
1619 assert bundle != NONEXISTENT_BUNDLE;
1620 bundle.expired = true;
1621 bundle.cacheKey = null;
1622 cacheList.remove(cacheKey, bundleRef);
1623 bundle = null;
1624 } else {
1625 CacheKey key = bundleRef.getCacheKey();
1626 long expirationTime = key.expirationTime;
1627 if (!bundle.expired && expirationTime >= 0
1628 && expirationTime <= System.currentTimeMillis()) {
1629 // its TTL period has expired.
1630 if (bundle != NONEXISTENT_BUNDLE) {
1631 // Synchronize here to call needsReload to avoid
1632 // redundant concurrent calls for the same bundle.
1633 synchronized (bundle) {
1634 expirationTime = key.expirationTime;
1635 if (!bundle.expired
1636 && expirationTime >= 0
1637 && expirationTime <= System
1638 .currentTimeMillis()) {
1639 try {
1640 bundle.expired = control.needsReload(
1641 key.getName(), key.getLocale(),
1642 key.getFormat(), key
1643 .getLoader(), bundle,
1644 key.loadTime);
1645 } catch (Exception e) {
1646 cacheKey.setCause(e);
1647 }
1648 if (bundle.expired) {
1649 // If the bundle needs to be reloaded, then
1650 // remove the bundle from the cache, but
1651 // return the bundle with the expired flag
1652 // on.
1653 bundle.cacheKey = null;
1654 cacheList.remove(cacheKey, bundleRef);
1655 } else {
1656 // Update the expiration control info. and reuse
1657 // the same bundle instance
1658 setExpirationTime(key, control);
1659 }
1660 }
1661 }
1662 } else {
1663 // We just remove NONEXISTENT_BUNDLE from the cache.
1664 cacheList.remove(cacheKey, bundleRef);
1665 bundle = null;
1666 }
1667 }
1668 }
1669 return bundle;
1670 }
1671
1672 /**
1673 * Put a new bundle in the cache.
1674 *
1675 * @param cacheKey the key for the resource bundle
1676 * @param bundle the resource bundle to be put in the cache
1677 * @return the ResourceBundle for the cacheKey; if someone has put
1678 * the bundle before this call, the one found in the cache is
1679 * returned.
1680 */
1681 private static final ResourceBundle putBundleInCache(
1682 CacheKey cacheKey, ResourceBundle bundle, Control control) {
1683 setExpirationTime(cacheKey, control);
1684 if (cacheKey.expirationTime != Control.TTL_DONT_CACHE) {
1685 CacheKey key = (CacheKey) cacheKey.clone();
1686 BundleReference bundleRef = new BundleReference(bundle,
1687 referenceQueue, key);
1688 bundle.cacheKey = key;
1689
1690 // Put the bundle in the cache if it's not been in the cache.
1691 BundleReference result = cacheList.putIfAbsent(key,
1692 bundleRef);
1693
1694 // If someone else has put the same bundle in the cache before
1695 // us and it has not expired, we should use the one in the cache.
1696 if (result != null) {
1697 ResourceBundle rb = result.get();
1698 if (rb != null && !rb.expired) {
1699 // Clear the back link to the cache key
1700 bundle.cacheKey = null;
1701 bundle = rb;
1702 // Clear the reference in the BundleReference so that
1703 // it won't be enqueued.
1704 bundleRef.clear();
1705 } else {
1706 // Replace the invalid (garbage collected or expired)
1707 // instance with the valid one.
1708 cacheList.put(key, bundleRef);
1709 }
1710 }
1711 }
1712 return bundle;
1713 }
1714
1715 private static final void setExpirationTime(CacheKey cacheKey,
1716 Control control) {
1717 long ttl = control.getTimeToLive(cacheKey.getName(), cacheKey
1718 .getLocale());
1719 if (ttl >= 0) {
1720 // If any expiration time is specified, set the time to be
1721 // expired in the cache.
1722 long now = System.currentTimeMillis();
1723 cacheKey.loadTime = now;
1724 cacheKey.expirationTime = now + ttl;
1725 } else if (ttl >= Control.TTL_NO_EXPIRATION_CONTROL) {
1726 cacheKey.expirationTime = ttl;
1727 } else {
1728 throw new IllegalArgumentException("Invalid Control: TTL="
1729 + ttl);
1730 }
1731 }
1732
1733 /**
1734 * Removes all resource bundles from the cache that have been loaded
1735 * using the caller's class loader.
1736 *
1737 * @since 1.6
1738 * @see ResourceBundle.Control#getTimeToLive(String,Locale)
1739 */
1740 public static final void clearCache() {
1741 clearCache(getLoader());
1742 }
1743
1744 /**
1745 * Removes all resource bundles from the cache that have been loaded
1746 * using the given class loader.
1747 *
1748 * @param loader the class loader
1749 * @exception NullPointerException if <code>loader</code> is null
1750 * @since 1.6
1751 * @see ResourceBundle.Control#getTimeToLive(String,Locale)
1752 */
1753 public static final void clearCache(ClassLoader loader) {
1754 if (loader == null) {
1755 throw new NullPointerException();
1756 }
1757 Set<CacheKey> set = cacheList.keySet();
1758 for (CacheKey key : set) {
1759 if (key.getLoader() == loader) {
1760 set.remove(key);
1761 }
1762 }
1763 }
1764
1765 /**
1766 * Gets an object for the given key from this resource bundle.
1767 * Returns null if this resource bundle does not contain an
1768 * object for the given key.
1769 *
1770 * @param key the key for the desired object
1771 * @exception NullPointerException if <code>key</code> is <code>null</code>
1772 * @return the object for the given key, or null
1773 */
1774 protected abstract Object handleGetObject(String key);
1775
1776 /**
1777 * Returns an enumeration of the keys.
1778 *
1779 * @return an <code>Enumeration</code> of the keys contained in
1780 * this <code>ResourceBundle</code> and its parent bundles.
1781 */
1782 public abstract Enumeration<String> getKeys();
1783
1784 /**
1785 * Determines whether the given <code>key</code> is contained in
1786 * this <code>ResourceBundle</code> or its parent bundles.
1787 *
1788 * @param key
1789 * the resource <code>key</code>
1790 * @return <code>true</code> if the given <code>key</code> is
1791 * contained in this <code>ResourceBundle</code> or its
1792 * parent bundles; <code>false</code> otherwise.
1793 * @exception NullPointerException
1794 * if <code>key</code> is <code>null</code>
1795 * @since 1.6
1796 */
1797 public boolean containsKey(String key) {
1798 if (key == null) {
1799 throw new NullPointerException();
1800 }
1801 for (ResourceBundle rb = this ; rb != null; rb = rb.parent) {
1802 if (rb.handleKeySet().contains(key)) {
1803 return true;
1804 }
1805 }
1806 return false;
1807 }
1808
1809 /**
1810 * Returns a <code>Set</code> of all keys contained in this
1811 * <code>ResourceBundle</code> and its parent bundles.
1812 *
1813 * @return a <code>Set</code> of all keys contained in this
1814 * <code>ResourceBundle</code> and its parent bundles.
1815 * @since 1.6
1816 */
1817 public Set<String> keySet() {
1818 Set<String> keys = new HashSet<String>();
1819 for (ResourceBundle rb = this ; rb != null; rb = rb.parent) {
1820 keys.addAll(rb.handleKeySet());
1821 }
1822 return keys;
1823 }
1824
1825 /**
1826 * Returns a <code>Set</code> of the keys contained <em>only</em>
1827 * in this <code>ResourceBundle</code>.
1828 *
1829 * <p>The default implementation returns a <code>Set</code> of the
1830 * keys returned by the {@link #getKeys() getKeys} method except
1831 * for the ones for which the {@link #handleGetObject(String)
1832 * handleGetObject} method returns <code>null</code>. Once the
1833 * <code>Set</code> has been created, the value is kept in this
1834 * <code>ResourceBundle</code> in order to avoid producing the
1835 * same <code>Set</code> in the next calls. Override this method
1836 * in subclass implementations for faster handling.
1837 *
1838 * @return a <code>Set</code> of the keys contained only in this
1839 * <code>ResourceBundle</code>
1840 * @since 1.6
1841 */
1842 protected Set<String> handleKeySet() {
1843 if (keySet == null) {
1844 synchronized (this ) {
1845 if (keySet == null) {
1846 Set<String> keys = new HashSet<String>();
1847 Enumeration<String> enumKeys = getKeys();
1848 while (enumKeys.hasMoreElements()) {
1849 String key = enumKeys.nextElement();
1850 if (handleGetObject(key) != null) {
1851 keys.add(key);
1852 }
1853 }
1854 keySet = keys;
1855 }
1856 }
1857 }
1858 return keySet;
1859 }
1860
1861 /**
1862 * <code>ResourceBundle.Control</code> defines a set of callback methods
1863 * that are invoked by the {@link ResourceBundle#getBundle(String,
1864 * Locale, ClassLoader, Control) ResourceBundle.getBundle} factory
1865 * methods during the bundle loading process. In other words, a
1866 * <code>ResourceBundle.Control</code> collaborates with the factory
1867 * methods for loading resource bundles. The default implementation of
1868 * the callback methods provides the information necessary for the
1869 * factory methods to perform the <a
1870 * href="./ResourceBundle.html#default_behavior">default behavior</a>.
1871 *
1872 * <p>In addition to the callback methods, the {@link
1873 * #toBundleName(String, Locale) toBundleName} and {@link
1874 * #toResourceName(String, String) toResourceName} methods are defined
1875 * primarily for convenience in implementing the callback
1876 * methods. However, the <code>toBundleName</code> method could be
1877 * overridden to provide different conventions in the organization and
1878 * packaging of localized resources. The <code>toResourceName</code>
1879 * method is <code>final</code> to avoid use of wrong resource and class
1880 * name separators.
1881 *
1882 * <p>Two factory methods, {@link #getControl(List)} and {@link
1883 * #getNoFallbackControl(List)}, provide
1884 * <code>ResourceBundle.Control</code> instances that implement common
1885 * variations of the default bundle loading process.
1886 *
1887 * <p>The formats returned by the {@link Control#getFormats(String)
1888 * getFormats} method and candidate locales returned by the {@link
1889 * ResourceBundle.Control#getCandidateLocales(String, Locale)
1890 * getCandidateLocales} method must be consistent in all
1891 * <code>ResourceBundle.getBundle</code> invocations for the same base
1892 * bundle. Otherwise, the <code>ResourceBundle.getBundle</code> methods
1893 * may return unintended bundles. For example, if only
1894 * <code>"java.class"</code> is returned by the <code>getFormats</code>
1895 * method for the first call to <code>ResourceBundle.getBundle</code>
1896 * and only <code>"java.properties"</code> for the second call, then the
1897 * second call will return the class-based one that has been cached
1898 * during the first call.
1899 *
1900 * <p>A <code>ResourceBundle.Control</code> instance must be thread-safe
1901 * if it's simultaneously used by multiple threads.
1902 * <code>ResourceBundle.getBundle</code> does not synchronize to call
1903 * the <code>ResourceBundle.Control</code> methods. The default
1904 * implementations of the methods are thread-safe.
1905 *
1906 * <p>Applications can specify <code>ResourceBundle.Control</code>
1907 * instances returned by the <code>getControl</code> factory methods or
1908 * created from a subclass of <code>ResourceBundle.Control</code> to
1909 * customize the bundle loading process. The following are examples of
1910 * changing the default bundle loading process.
1911 *
1912 * <p><b>Example 1</b>
1913 *
1914 * <p>The following code lets <code>ResourceBundle.getBundle</code> look
1915 * up only properties-based resources.
1916 *
1917 * <pre>
1918 * import java.util.*;
1919 * import static java.util.ResourceBundle.Control.*;
1920 * ...
1921 * ResourceBundle bundle =
1922 * ResourceBundle.getBundle("MyResources", new Locale("fr", "CH"),
1923 * ResourceBundle.Control.getControl(FORMAT_PROPERTIES));
1924 * </pre>
1925 *
1926 * Given the resource bundles in the <a
1927 * href="./ResourceBundle.html#default_behavior_example">example</a> in
1928 * the <code>ResourceBundle.getBundle</code> description, this
1929 * <code>ResourceBundle.getBundle</code> call loads
1930 * <code>MyResources_fr_CH.properties</code> whose parent is
1931 * <code>MyResources_fr.properties</code> whose parent is
1932 * <code>MyResources.properties</code>. (<code>MyResources_fr_CH.properties</code>
1933 * is not hidden, but <code>MyResources_fr_CH.class</code> is.)
1934 *
1935 * <p><b>Example 2</b>
1936 *
1937 * <p>The following is an example of loading XML-based bundles
1938 * using {@link Properties#loadFromXML(java.io.InputStream)
1939 * Properties.loadFromXML}.
1940 *
1941 * <pre>
1942 * ResourceBundle rb = ResourceBundle.getBundle("Messages",
1943 * new ResourceBundle.Control() {
1944 * public List<String> getFormats(String baseName) {
1945 * if (baseName == null)
1946 * throw new NullPointerException();
1947 * return Arrays.asList("xml");
1948 * }
1949 * public ResourceBundle newBundle(String baseName,
1950 * Locale locale,
1951 * String format,
1952 * ClassLoader loader,
1953 * boolean reload)
1954 * throws IllegalAccessException,
1955 * InstantiationException,
1956 * IOException {
1957 * if (baseName == null || locale == null
1958 * || format == null || loader == null)
1959 * throw new NullPointerException();
1960 * ResourceBundle bundle = null;
1961 * if (format.equals("xml")) {
1962 * String bundleName = toBundleName(baseName, locale);
1963 * String resourceName = toResourceName(bundleName, format);
1964 * InputStream stream = null;
1965 * if (reload) {
1966 * URL url = loader.getResource(resourceName);
1967 * if (url != null) {
1968 * URLConnection connection = url.openConnection();
1969 * if (connection != null) {
1970 * // Disable caches to get fresh data for
1971 * // reloading.
1972 * connection.setUseCaches(false);
1973 * stream = connection.getInputStream();
1974 * }
1975 * }
1976 * } else {
1977 * stream = loader.getResourceAsStream(resourceName);
1978 * }
1979 * if (stream != null) {
1980 * BufferedInputStream bis = new BufferedInputStream(stream);
1981 * bundle = new XMLResourceBundle(bis);
1982 * bis.close();
1983 * }
1984 * }
1985 * return bundle;
1986 * }
1987 * });
1988 *
1989 * ...
1990 *
1991 * private static class XMLResourceBundle extends ResourceBundle {
1992 * private Properties props;
1993 * XMLResourceBundle(InputStream stream) throws IOException {
1994 * props = new Properties();
1995 * props.loadFromXML(stream);
1996 * }
1997 * protected Object handleGetObject(String key) {
1998 * return props.getProperty(key);
1999 * }
2000 * public Enumeration<String> getKeys() {
2001 * ...
2002 * }
2003 * }
2004 * </pre>
2005 *
2006 * @since 1.6
2007 */
2008 public static class Control {
2009 /**
2010 * The default format <code>List</code>, which contains the strings
2011 * <code>"java.class"</code> and <code>"java.properties"</code>, in
2012 * this order. This <code>List</code> is {@linkplain
2013 * Collections#unmodifiableList(List) unmodifiable}.
2014 *
2015 * @see #getFormats(String)
2016 */
2017 public static final List<String> FORMAT_DEFAULT = Collections
2018 .unmodifiableList(Arrays.asList("java.class",
2019 "java.properties"));
2020
2021 /**
2022 * The class-only format <code>List</code> containing
2023 * <code>"java.class"</code>. This <code>List</code> is {@linkplain
2024 * Collections#unmodifiableList(List) unmodifiable}.
2025 *
2026 * @see #getFormats(String)
2027 */
2028 public static final List<String> FORMAT_CLASS = Collections
2029 .unmodifiableList(Arrays.asList("java.class"));
2030
2031 /**
2032 * The properties-only format <code>List</code> containing
2033 * <code>"java.properties"</code>. This <code>List</code> is
2034 * {@linkplain Collections#unmodifiableList(List) unmodifiable}.
2035 *
2036 * @see #getFormats(String)
2037 */
2038 public static final List<String> FORMAT_PROPERTIES = Collections
2039 .unmodifiableList(Arrays.asList("java.properties"));
2040
2041 /**
2042 * The time-to-live constant for not caching loaded resource bundle
2043 * instances.
2044 *
2045 * @see #getTimeToLive(String, Locale)
2046 */
2047 public static final long TTL_DONT_CACHE = -1;
2048
2049 /**
2050 * The time-to-live constant for disabling the expiration control
2051 * for loaded resource bundle instances in the cache.
2052 *
2053 * @see #getTimeToLive(String, Locale)
2054 */
2055 public static final long TTL_NO_EXPIRATION_CONTROL = -2;
2056
2057 private static final Control INSTANCE = new Control();
2058
2059 /**
2060 * Sole constructor. (For invocation by subclass constructors,
2061 * typically implicit.)
2062 */
2063 protected Control() {
2064 }
2065
2066 /**
2067 * Returns a <code>ResourceBundle.Control</code> in which the {@link
2068 * #getFormats(String) getFormats} method returns the specified
2069 * <code>formats</code>. The <code>formats</code> must be equal to
2070 * one of {@link Control#FORMAT_PROPERTIES}, {@link
2071 * Control#FORMAT_CLASS} or {@link
2072 * Control#FORMAT_DEFAULT}. <code>ResourceBundle.Control</code>
2073 * instances returned by this method are singletons and thread-safe.
2074 *
2075 * <p>Specifying {@link Control#FORMAT_DEFAULT} is equivalent to
2076 * instantiating the <code>ResourceBundle.Control</code> class,
2077 * except that this method returns a singleton.
2078 *
2079 * @param formats
2080 * the formats to be returned by the
2081 * <code>ResourceBundle.Control.getFormats</code> method
2082 * @return a <code>ResourceBundle.Control</code> supporting the
2083 * specified <code>formats</code>
2084 * @exception NullPointerException
2085 * if <code>formats</code> is <code>null</code>
2086 * @exception IllegalArgumentException
2087 * if <code>formats</code> is unknown
2088 */
2089 public static final Control getControl(List<String> formats) {
2090 if (formats.equals(Control.FORMAT_PROPERTIES)) {
2091 return SingleFormatControl.PROPERTIES_ONLY;
2092 }
2093 if (formats.equals(Control.FORMAT_CLASS)) {
2094 return SingleFormatControl.CLASS_ONLY;
2095 }
2096 if (formats.equals(Control.FORMAT_DEFAULT)) {
2097 return Control.INSTANCE;
2098 }
2099 throw new IllegalArgumentException();
2100 }
2101
2102 /**
2103 * Returns a <code>ResourceBundle.Control</code> in which the {@link
2104 * #getFormats(String) getFormats} method returns the specified
2105 * <code>formats</code> and the {@link
2106 * Control#getFallbackLocale(String, Locale) getFallbackLocale}
2107 * method returns <code>null</code>. The <code>formats</code> must
2108 * be equal to one of {@link Control#FORMAT_PROPERTIES}, {@link
2109 * Control#FORMAT_CLASS} or {@link Control#FORMAT_DEFAULT}.
2110 * <code>ResourceBundle.Control</code> instances returned by this
2111 * method are singletons and thread-safe.
2112 *
2113 * @param formats
2114 * the formats to be returned by the
2115 * <code>ResourceBundle.Control.getFormats</code> method
2116 * @return a <code>ResourceBundle.Control</code> supporting the
2117 * specified <code>formats</code> with no fallback
2118 * <code>Locale</code> support
2119 * @exception NullPointerException
2120 * if <code>formats</code> is <code>null</code>
2121 * @exception IllegalArgumentException
2122 * if <code>formats</code> is unknown
2123 */
2124 public static final Control getNoFallbackControl(
2125 List<String> formats) {
2126 if (formats.equals(Control.FORMAT_DEFAULT)) {
2127 return NoFallbackControl.NO_FALLBACK;
2128 }
2129 if (formats.equals(Control.FORMAT_PROPERTIES)) {
2130 return NoFallbackControl.PROPERTIES_ONLY_NO_FALLBACK;
2131 }
2132 if (formats.equals(Control.FORMAT_CLASS)) {
2133 return NoFallbackControl.CLASS_ONLY_NO_FALLBACK;
2134 }
2135 throw new IllegalArgumentException();
2136 }
2137
2138 /**
2139 * Returns a <code>List</code> of <code>String</code>s containing
2140 * formats to be used to load resource bundles for the given
2141 * <code>baseName</code>. The <code>ResourceBundle.getBundle</code>
2142 * factory method tries to load resource bundles with formats in the
2143 * order specified by the list. The list returned by this method
2144 * must have at least one <code>String</code>. The predefined
2145 * formats are <code>"java.class"</code> for class-based resource
2146 * bundles and <code>"java.properties"</code> for {@linkplain
2147 * PropertyResourceBundle properties-based} ones. Strings starting
2148 * with <code>"java."</code> are reserved for future extensions and
2149 * must not be used by application-defined formats.
2150 *
2151 * <p>It is not a requirement to return an immutable (unmodifiable)
2152 * <code>List</code>. However, the returned <code>List</code> must
2153 * not be mutated after it has been returned by
2154 * <code>getFormats</code>.
2155 *
2156 * <p>The default implementation returns {@link #FORMAT_DEFAULT} so
2157 * that the <code>ResourceBundle.getBundle</code> factory method
2158 * looks up first class-based resource bundles, then
2159 * properties-based ones.
2160 *
2161 * @param baseName
2162 * the base name of the resource bundle, a fully qualified class
2163 * name
2164 * @return a <code>List</code> of <code>String</code>s containing
2165 * formats for loading resource bundles.
2166 * @exception NullPointerException
2167 * if <code>baseName</code> is null
2168 * @see #FORMAT_DEFAULT
2169 * @see #FORMAT_CLASS
2170 * @see #FORMAT_PROPERTIES
2171 */
2172 public List<String> getFormats(String baseName) {
2173 if (baseName == null) {
2174 throw new NullPointerException();
2175 }
2176 return FORMAT_DEFAULT;
2177 }
2178
2179 /**
2180 * Returns a <code>List</code> of <code>Locale</code>s as candidate
2181 * locales for <code>baseName</code> and <code>locale</code>. This
2182 * method is called by the <code>ResourceBundle.getBundle</code>
2183 * factory method each time the factory method tries finding a
2184 * resource bundle for a target <code>Locale</code>.
2185 *
2186 * <p>The sequence of the candidate locales also corresponds to the
2187 * runtime resource lookup path (also known as the <I>parent
2188 * chain</I>), if the corresponding resource bundles for the
2189 * candidate locales exist and their parents are not defined by
2190 * loaded resource bundles themselves. The last element of the list
2191 * must be a {@linkplain Locale#ROOT root locale} if it is desired to
2192 * have the base bundle as the terminal of the parent chain.
2193 *
2194 * <p>If the given locale is equal to <code>Locale.ROOT</code> (the
2195 * root locale), a <code>List</code> containing only the root
2196 * <code>Locale</code> must be returned. In this case, the
2197 * <code>ResourceBundle.getBundle</code> factory method loads only
2198 * the base bundle as the resulting resource bundle.
2199 *
2200 * <p>It is not a requirement to return an immutable
2201 * (unmodifiable) <code>List</code>. However, the returned
2202 * <code>List</code> must not be mutated after it has been
2203 * returned by <code>getCandidateLocales</code>.
2204 *
2205 * <p>The default implementation returns a <code>List</code> containing
2206 * <code>Locale</code>s in the following sequence:
2207 * <pre>
2208 * Locale(language, country, variant)
2209 * Locale(language, country)
2210 * Locale(language)
2211 * Locale.ROOT
2212 * </pre>
2213 * where <code>language</code>, <code>country</code> and
2214 * <code>variant</code> are the language, country and variant values
2215 * of the given <code>locale</code>, respectively. Locales where the
2216 * final component values are empty strings are omitted.
2217 *
2218 * <p>The default implementation uses an {@link ArrayList} that
2219 * overriding implementations may modify before returning it to the
2220 * caller. However, a subclass must not modify it after it has
2221 * been returned by <code>getCandidateLocales</code>.
2222 *
2223 * <p>For example, if the given <code>baseName</code> is "Messages"
2224 * and the given <code>locale</code> is
2225 * <code>Locale("ja", "", "XX")</code>, then a
2226 * <code>List</code> of <code>Locale</code>s:
2227 * <pre>
2228 * Locale("ja", "", "XX")
2229 * Locale("ja")
2230 * Locale.ROOT
2231 * </pre>
2232 * is returned. And if the resource bundles for the "ja" and
2233 * "" <code>Locale</code>s are found, then the runtime resource
2234 * lookup path (parent chain) is:
2235 * <pre>
2236 * Messages_ja -> Messages
2237 * </pre>
2238 *
2239 * @param baseName
2240 * the base name of the resource bundle, a fully
2241 * qualified class name
2242 * @param locale
2243 * the locale for which a resource bundle is desired
2244 * @return a <code>List</code> of candidate
2245 * <code>Locale</code>s for the given <code>locale</code>
2246 * @exception NullPointerException
2247 * if <code>baseName</code> or <code>locale</code> is
2248 * <code>null</code>
2249 */
2250 public List<Locale> getCandidateLocales(String baseName,
2251 Locale locale) {
2252 if (baseName == null) {
2253 throw new NullPointerException();
2254 }
2255 String language = locale.getLanguage();
2256 String country = locale.getCountry();
2257 String variant = locale.getVariant();
2258
2259 List<Locale> locales = new ArrayList<Locale>(4);
2260 if (variant.length() > 0) {
2261 locales.add(locale);
2262 }
2263 if (country.length() > 0) {
2264 locales.add((locales.size() == 0) ? locale : Locale
2265 .getInstance(language, country, ""));
2266 }
2267 if (language.length() > 0) {
2268 locales.add((locales.size() == 0) ? locale : Locale
2269 .getInstance(language, "", ""));
2270 }
2271 locales.add(Locale.ROOT);
2272 return locales;
2273 }
2274
2275 /**
2276 * Returns a <code>Locale</code> to be used as a fallback locale for
2277 * further resource bundle searches by the
2278 * <code>ResourceBundle.getBundle</code> factory method. This method
2279 * is called from the factory method every time when no resulting
2280 * resource bundle has been found for <code>baseName</code> and
2281 * <code>locale</code>, where locale is either the parameter for
2282 * <code>ResourceBundle.getBundle</code> or the previous fallback
2283 * locale returned by this method.
2284 *
2285 * <p>The method returns <code>null</code> if no further fallback
2286 * search is desired.
2287 *
2288 * <p>The default implementation returns the {@linkplain
2289 * Locale#getDefault() default <code>Locale</code>} if the given
2290 * <code>locale</code> isn't the default one. Otherwise,
2291 * <code>null</code> is returned.
2292 *
2293 * @param baseName
2294 * the base name of the resource bundle, a fully
2295 * qualified class name for which
2296 * <code>ResourceBundle.getBundle</code> has been
2297 * unable to find any resource bundles (except for the
2298 * base bundle)
2299 * @param locale
2300 * the <code>Locale</code> for which
2301 * <code>ResourceBundle.getBundle</code> has been
2302 * unable to find any resource bundles (except for the
2303 * base bundle)
2304 * @return a <code>Locale</code> for the fallback search,
2305 * or <code>null</code> if no further fallback search
2306 * is desired.
2307 * @exception NullPointerException
2308 * if <code>baseName</code> or <code>locale</code>
2309 * is <code>null</code>
2310 */
2311 public Locale getFallbackLocale(String baseName, Locale locale) {
2312 if (baseName == null) {
2313 throw new NullPointerException();
2314 }
2315 Locale defaultLocale = Locale.getDefault();
2316 return locale.equals(defaultLocale) ? null : defaultLocale;
2317 }
2318
2319 /**
2320 * Instantiates a resource bundle for the given bundle name of the
2321 * given format and locale, using the given class loader if
2322 * necessary. This method returns <code>null</code> if there is no
2323 * resource bundle available for the given parameters. If a resource
2324 * bundle can't be instantiated due to an unexpected error, the
2325 * error must be reported by throwing an <code>Error</code> or
2326 * <code>Exception</code> rather than simply returning
2327 * <code>null</code>.
2328 *
2329 * <p>If the <code>reload</code> flag is <code>true</code>, it
2330 * indicates that this method is being called because the previously
2331 * loaded resource bundle has expired.
2332 *
2333 * <p>The default implementation instantiates a
2334 * <code>ResourceBundle</code> as follows.
2335 *
2336 * <ul>
2337 *
2338 * <li>The bundle name is obtained by calling {@link
2339 * #toBundleName(String, Locale) toBundleName(baseName,
2340 * locale)}.</li>
2341 *
2342 * <li>If <code>format</code> is <code>"java.class"</code>, the
2343 * {@link Class} specified by the bundle name is loaded by calling
2344 * {@link ClassLoader#loadClass(String)}. Then, a
2345 * <code>ResourceBundle</code> is instantiated by calling {@link
2346 * Class#newInstance()}. Note that the <code>reload</code> flag is
2347 * ignored for loading class-based resource bundles in this default
2348 * implementation.</li>
2349 *
2350 * <li>If <code>format</code> is <code>"java.properties"</code>,
2351 * {@link #toResourceName(String, String) toResourceName(bundlename,
2352 * "properties")} is called to get the resource name.
2353 * If <code>reload</code> is <code>true</code>, {@link
2354 * ClassLoader#getResource(String) load.getResource} is called
2355 * to get a {@link URL} for creating a {@link
2356 * URLConnection}. This <code>URLConnection</code> is used to
2357 * {@linkplain URLConnection#setUseCaches(boolean) disable the
2358 * caches} of the underlying resource loading layers,
2359 * and to {@linkplain URLConnection#getInputStream() get an
2360 * <code>InputStream</code>}.
2361 * Otherwise, {@link ClassLoader#getResourceAsStream(String)
2362 * loader.getResourceAsStream} is called to get an {@link
2363 * InputStream}. Then, a {@link
2364 * PropertyResourceBundle} is constructed with the
2365 * <code>InputStream</code>.</li>
2366 *
2367 * <li>If <code>format</code> is neither <code>"java.class"</code>
2368 * nor <code>"java.properties"</code>, an
2369 * <code>IllegalArgumentException</code> is thrown.</li>
2370 *
2371 * </ul>
2372 *
2373 * @param baseName
2374 * the base bundle name of the resource bundle, a fully
2375 * qualified class name
2376 * @param locale
2377 * the locale for which the resource bundle should be
2378 * instantiated
2379 * @param format
2380 * the resource bundle format to be loaded
2381 * @param loader
2382 * the <code>ClassLoader</code> to use to load the bundle
2383 * @param reload
2384 * the flag to indicate bundle reloading; <code>true</code>
2385 * if reloading an expired resource bundle,
2386 * <code>false</code> otherwise
2387 * @return the resource bundle instance,
2388 * or <code>null</code> if none could be found.
2389 * @exception NullPointerException
2390 * if <code>bundleName</code>, <code>locale</code>,
2391 * <code>format</code>, or <code>loader</code> is
2392 * <code>null</code>, or if <code>null</code> is returned by
2393 * {@link #toBundleName(String, Locale) toBundleName}
2394 * @exception IllegalArgumentException
2395 * if <code>format</code> is unknown, or if the resource
2396 * found for the given parameters contains malformed data.
2397 * @exception ClassCastException
2398 * if the loaded class cannot be cast to <code>ResourceBundle</code>
2399 * @exception IllegalAccessException
2400 * if the class or its nullary constructor is not
2401 * accessible.
2402 * @exception InstantiationException
2403 * if the instantiation of a class fails for some other
2404 * reason.
2405 * @exception ExceptionInInitializerError
2406 * if the initialization provoked by this method fails.
2407 * @exception SecurityException
2408 * If a security manager is present and creation of new
2409 * instances is denied. See {@link Class#newInstance()}
2410 * for details.
2411 * @exception IOException
2412 * if an error occurred when reading resources using
2413 * any I/O operations
2414 */
2415 public ResourceBundle newBundle(String baseName, Locale locale,
2416 String format, ClassLoader loader, boolean reload)
2417 throws IllegalAccessException, InstantiationException,
2418 IOException {
2419 String bundleName = toBundleName(baseName, locale);
2420 ResourceBundle bundle = null;
2421 if (format.equals("java.class")) {
2422 try {
2423 Class<? extends ResourceBundle> bundleClass = (Class<? extends ResourceBundle>) loader
2424 .loadClass(bundleName);
2425
2426 // If the class isn't a ResourceBundle subclass, throw a
2427 // ClassCastException.
2428 if (ResourceBundle.class
2429 .isAssignableFrom(bundleClass)) {
2430 bundle = bundleClass.newInstance();
2431 } else {
2432 throw new ClassCastException(bundleClass
2433 .getName()
2434 + " cannot be cast to ResourceBundle");
2435 }
2436 } catch (ClassNotFoundException e) {
2437 }
2438 } else if (format.equals("java.properties")) {
2439 final String resourceName = toResourceName(bundleName,
2440 "properties");
2441 final ClassLoader classLoader = loader;
2442 final boolean reloadFlag = reload;
2443 InputStream stream = null;
2444 try {
2445 stream = AccessController
2446 .doPrivileged(new PrivilegedExceptionAction<InputStream>() {
2447 public InputStream run()
2448 throws IOException {
2449 InputStream is = null;
2450 if (reloadFlag) {
2451 URL url = classLoader
2452 .getResource(resourceName);
2453 if (url != null) {
2454 URLConnection connection = url
2455 .openConnection();
2456 if (connection != null) {
2457 // Disable caches to get fresh data for
2458 // reloading.
2459 connection
2460 .setUseCaches(false);
2461 is = connection
2462 .getInputStream();
2463 }
2464 }
2465 } else {
2466 is = classLoader
2467 .getResourceAsStream(resourceName);
2468 }
2469 return is;
2470 }
2471 });
2472 } catch (PrivilegedActionException e) {
2473 throw (IOException) e.getException();
2474 }
2475 if (stream != null) {
2476 try {
2477 bundle = new PropertyResourceBundle(stream);
2478 } finally {
2479 stream.close();
2480 }
2481 }
2482 } else {
2483 throw new IllegalArgumentException("unknown format: "
2484 + format);
2485 }
2486 return bundle;
2487 }
2488
2489 /**
2490 * Returns the time-to-live (TTL) value for resource bundles that
2491 * are loaded under this
2492 * <code>ResourceBundle.Control</code>. Positive time-to-live values
2493 * specify the number of milliseconds a bundle can remain in the
2494 * cache without being validated against the source data from which
2495 * it was constructed. The value 0 indicates that a bundle must be
2496 * validated each time it is retrieved from the cache. {@link
2497 * #TTL_DONT_CACHE} specifies that loaded resource bundles are not
2498 * put in the cache. {@link #TTL_NO_EXPIRATION_CONTROL} specifies
2499 * that loaded resource bundles are put in the cache with no
2500 * expiration control.
2501 *
2502 * <p>The expiration affects only the bundle loading process by the
2503 * <code>ResourceBundle.getBundle</code> factory method. That is,
2504 * if the factory method finds a resource bundle in the cache that
2505 * has expired, the factory method calls the {@link
2506 * #needsReload(String, Locale, String, ClassLoader, ResourceBundle,
2507 * long) needsReload} method to determine whether the resource
2508 * bundle needs to be reloaded. If <code>needsReload</code> returns
2509 * <code>true</code>, the cached resource bundle instance is removed
2510 * from the cache. Otherwise, the instance stays in the cache,
2511 * updated with the new TTL value returned by this method.
2512 *
2513 * <p>All cached resource bundles are subject to removal from the
2514 * cache due to memory constraints of the runtime environment.
2515 * Returning a large positive value doesn't mean to lock loaded
2516 * resource bundles in the cache.
2517 *
2518 * <p>The default implementation returns {@link #TTL_NO_EXPIRATION_CONTROL}.
2519 *
2520 * @param baseName
2521 * the base name of the resource bundle for which the
2522 * expiration value is specified.
2523 * @param locale
2524 * the locale of the resource bundle for which the
2525 * expiration value is specified.
2526 * @return the time (0 or a positive millisecond offset from the
2527 * cached time) to get loaded bundles expired in the cache,
2528 * {@link #TTL_NO_EXPIRATION_CONTROL} to disable the
2529 * expiration control, or {@link #TTL_DONT_CACHE} to disable
2530 * caching.
2531 * @exception NullPointerException
2532 * if <code>baseName</code> or <code>locale</code> is
2533 * <code>null</code>
2534 */
2535 public long getTimeToLive(String baseName, Locale locale) {
2536 if (baseName == null || locale == null) {
2537 throw new NullPointerException();
2538 }
2539 return TTL_NO_EXPIRATION_CONTROL;
2540 }
2541
2542 /**
2543 * Determines if the expired <code>bundle</code> in the cache needs
2544 * to be reloaded based on the loading time given by
2545 * <code>loadTime</code> or some other criteria. The method returns
2546 * <code>true</code> if reloading is required; <code>false</code>
2547 * otherwise. <code>loadTime</code> is a millisecond offset since
2548 * the <a href="Calendar.html#Epoch"> <code>Calendar</code>
2549 * Epoch</a>.
2550 *
2551 * The calling <code>ResourceBundle.getBundle</code> factory method
2552 * calls this method on the <code>ResourceBundle.Control</code>
2553 * instance used for its current invocation, not on the instance
2554 * used in the invocation that originally loaded the resource
2555 * bundle.
2556 *
2557 * <p>The default implementation compares <code>loadTime</code> and
2558 * the last modified time of the source data of the resource
2559 * bundle. If it's determined that the source data has been modified
2560 * since <code>loadTime</code>, <code>true</code> is
2561 * returned. Otherwise, <code>false</code> is returned. This
2562 * implementation assumes that the given <code>format</code> is the
2563 * same string as its file suffix if it's not one of the default
2564 * formats, <code>"java.class"</code> or
2565 * <code>"java.properties"</code>.
2566 *
2567 * @param baseName
2568 * the base bundle name of the resource bundle, a
2569 * fully qualified class name
2570 * @param locale
2571 * the locale for which the resource bundle
2572 * should be 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 bundle
2578 * the resource bundle instance that has been expired
2579 * in the cache
2580 * @param loadTime
2581 * the time when <code>bundle</code> was loaded and put
2582 * in the cache
2583 * @return <code>true</code> if the expired bundle needs to be
2584 * reloaded; <code>false</code> otherwise.
2585 * @exception NullPointerException
2586 * if <code>baseName</code>, <code>locale</code>,
2587 * <code>format</code>, <code>loader</code>, or
2588 * <code>bundle</code> is <code>null</code>
2589 */
2590 public boolean needsReload(String baseName, Locale locale,
2591 String format, ClassLoader loader,
2592 ResourceBundle bundle, long loadTime) {
2593 if (bundle == null) {
2594 throw new NullPointerException();
2595 }
2596 if (format.equals("java.class")
2597 || format.equals("java.properties")) {
2598 format = format.substring(5);
2599 }
2600 boolean result = false;
2601 try {
2602 String resourceName = toResourceName(toBundleName(
2603 baseName, locale), format);
2604 URL url = loader.getResource(resourceName);
2605 if (url != null) {
2606 long lastModified = 0;
2607 URLConnection connection = url.openConnection();
2608 if (connection != null) {
2609 // disable caches to get the correct data
2610 connection.setUseCaches(false);
2611 if (connection instanceof JarURLConnection) {
2612 JarEntry ent = ((JarURLConnection) connection)
2613 .getJarEntry();
2614 if (ent != null) {
2615 lastModified = ent.getTime();
2616 if (lastModified == -1) {
2617 lastModified = 0;
2618 }
2619 }
2620 } else {
2621 lastModified = connection.getLastModified();
2622 }
2623 }
2624 result = lastModified >= loadTime;
2625 }
2626 } catch (NullPointerException npe) {
2627 throw npe;
2628 } catch (Exception e) {
2629 // ignore other exceptions
2630 }
2631 return result;
2632 }
2633
2634 /**
2635 * Converts the given <code>baseName</code> and <code>locale</code>
2636 * to the bundle name. This method is called from the default
2637 * implementation of the {@link #newBundle(String, Locale, String,
2638 * ClassLoader, boolean) newBundle} and {@link #needsReload(String,
2639 * Locale, String, ClassLoader, ResourceBundle, long) needsReload}
2640 * methods.
2641 *
2642 * <p>This implementation returns the following value:
2643 * <pre>
2644 * baseName + "_" + language + "_" + country + "_" + variant
2645 * </pre>
2646 * where <code>language</code>, <code>country</code> and
2647 * <code>variant</code> are the language, country and variant values
2648 * of <code>locale</code>, respectively. Final component values that
2649 * are empty Strings are omitted along with the preceding '_'. If
2650 * all of the values are empty strings, then <code>baseName</code>
2651 * is returned.
2652 *
2653 * <p>For example, if <code>baseName</code> is
2654 * <code>"baseName"</code> and <code>locale</code> is
2655 * <code>Locale("ja", "", "XX")</code>, then
2656 * <code>"baseName_ja_ _XX"</code> is returned. If the given
2657 * locale is <code>Locale("en")</code>, then
2658 * <code>"baseName_en"</code> is returned.
2659 *
2660 * <p>Overriding this method allows applications to use different
2661 * conventions in the organization and packaging of localized
2662 * resources.
2663 *
2664 * @param baseName
2665 * the base name of the resource bundle, a fully
2666 * qualified class name
2667 * @param locale
2668 * the locale for which a resource bundle should be
2669 * loaded
2670 * @return the bundle name for the resource bundle
2671 * @exception NullPointerException
2672 * if <code>baseName</code> or <code>locale</code>
2673 * is <code>null</code>
2674 */
2675 public String toBundleName(String baseName, Locale locale) {
2676 if (locale == Locale.ROOT) {
2677 return baseName;
2678 }
2679
2680 String language = locale.getLanguage();
2681 String country = locale.getCountry();
2682 String variant = locale.getVariant();
2683
2684 if (language == "" && country == "" && variant == "") {
2685 return baseName;
2686 }
2687
2688 StringBuilder sb = new StringBuilder(baseName);
2689 sb.append('_');
2690 if (variant != "") {
2691 sb.append(language).append('_').append(country).append(
2692 '_').append(variant);
2693 } else if (country != "") {
2694 sb.append(language).append('_').append(country);
2695 } else {
2696 sb.append(language);
2697 }
2698 return sb.toString();
2699
2700 }
2701
2702 /**
2703 * Converts the given <code>bundleName</code> to the form required
2704 * by the {@link ClassLoader#getResource ClassLoader.getResource}
2705 * method by replacing all occurrences of <code>'.'</code> in
2706 * <code>bundleName</code> with <code>'/'</code> and appending a
2707 * <code>'.'</code> and the given file <code>suffix</code>. For
2708 * example, if <code>bundleName</code> is
2709 * <code>"foo.bar.MyResources_ja_JP"</code> and <code>suffix</code>
2710 * is <code>"properties"</code>, then
2711 * <code>"foo/bar/MyResources_ja_JP.properties"</code> is returned.
2712 *
2713 * @param bundleName
2714 * the bundle name
2715 * @param suffix
2716 * the file type suffix
2717 * @return the converted resource name
2718 * @exception NullPointerException
2719 * if <code>bundleName</code> or <code>suffix</code>
2720 * is <code>null</code>
2721 */
2722 public final String toResourceName(String bundleName,
2723 String suffix) {
2724 StringBuilder sb = new StringBuilder(bundleName.length()
2725 + 1 + suffix.length());
2726 sb.append(bundleName.replace('.', '/')).append('.').append(
2727 suffix);
2728 return sb.toString();
2729 }
2730 }
2731
2732 private static class SingleFormatControl extends Control {
2733 private static final Control PROPERTIES_ONLY = new SingleFormatControl(
2734 FORMAT_PROPERTIES);
2735
2736 private static final Control CLASS_ONLY = new SingleFormatControl(
2737 FORMAT_CLASS);
2738
2739 private final List<String> formats;
2740
2741 protected SingleFormatControl(List<String> formats) {
2742 this .formats = formats;
2743 }
2744
2745 public List<String> getFormats(String baseName) {
2746 if (baseName == null) {
2747 throw new NullPointerException();
2748 }
2749 return formats;
2750 }
2751 }
2752
2753 private static final class NoFallbackControl extends
2754 SingleFormatControl {
2755 private static final Control NO_FALLBACK = new NoFallbackControl(
2756 FORMAT_DEFAULT);
2757
2758 private static final Control PROPERTIES_ONLY_NO_FALLBACK = new NoFallbackControl(
2759 FORMAT_PROPERTIES);
2760
2761 private static final Control CLASS_ONLY_NO_FALLBACK = new NoFallbackControl(
2762 FORMAT_CLASS);
2763
2764 protected NoFallbackControl(List<String> formats) {
2765 super (formats);
2766 }
2767
2768 public Locale getFallbackLocale(String baseName, Locale locale) {
2769 if (baseName == null || locale == null) {
2770 throw new NullPointerException();
2771 }
2772 return null;
2773 }
2774 }
2775 }
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