1 /*
   2  * Copyright (c) 1996, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /*
  27  * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
  28  * (C) Copyright IBM Corp. 1996 - 1999 - All Rights Reserved
  29  *
  30  * The original version of this source code and documentation
  31  * is copyrighted and owned by Taligent, Inc., a wholly-owned
  32  * subsidiary of IBM. These materials are provided under terms
  33  * of a License Agreement between Taligent and Sun. This technology
  34  * is protected by multiple US and International patents.
  35  *
  36  * This notice and attribution to Taligent may not be removed.
  37  * Taligent is a registered trademark of Taligent, Inc.
  38  *
  39  */
  40 
  41 package java.util;
  42 
  43 import java.io.IOException;
  44 import java.io.InputStream;
  45 import java.lang.ref.ReferenceQueue;
  46 import java.lang.ref.SoftReference;
  47 import java.lang.ref.WeakReference;
  48 import java.lang.reflect.Constructor;
  49 import java.lang.reflect.InvocationTargetException;
  50 import java.lang.reflect.Modifier;
  51 import java.lang.reflect.Module;
  52 import java.net.JarURLConnection;
  53 import java.net.URL;
  54 import java.net.URLConnection;
  55 import java.security.AccessController;
  56 import java.security.PrivilegedAction;
  57 import java.security.PrivilegedActionException;
  58 import java.security.PrivilegedExceptionAction;
  59 import java.util.concurrent.ConcurrentHashMap;
  60 import java.util.concurrent.ConcurrentMap;
  61 import java.util.jar.JarEntry;
  62 import java.util.spi.ResourceBundleControlProvider;
  63 import java.util.spi.ResourceBundleProvider;
  64 
  65 import jdk.internal.misc.JavaUtilResourceBundleAccess;
  66 import jdk.internal.misc.SharedSecrets;
  67 import jdk.internal.reflect.CallerSensitive;
  68 import jdk.internal.reflect.Reflection;
  69 import sun.util.locale.BaseLocale;
  70 import sun.util.locale.LocaleObjectCache;
  71 import sun.util.locale.provider.ResourceBundleProviderSupport;
  72 import static sun.security.util.SecurityConstants.GET_CLASSLOADER_PERMISSION;
  73 
  74 
  75 /**
  76  *
  77  * Resource bundles contain locale-specific objects.  When your program needs a
  78  * locale-specific resource, a <code>String</code> for example, your program can
  79  * load it from the resource bundle that is appropriate for the current user's
  80  * locale. In this way, you can write program code that is largely independent
  81  * of the user's locale isolating most, if not all, of the locale-specific
  82  * information in resource bundles.
  83  *
  84  * <p>
  85  * This allows you to write programs that can:
  86  * <UL>
  87  * <LI> be easily localized, or translated, into different languages
  88  * <LI> handle multiple locales at once
  89  * <LI> be easily modified later to support even more locales
  90  * </UL>
  91  *
  92  * <P>
  93  * Resource bundles belong to families whose members share a common base
  94  * name, but whose names also have additional components that identify
  95  * their locales. For example, the base name of a family of resource
  96  * bundles might be "MyResources". The family should have a default
  97  * resource bundle which simply has the same name as its family -
  98  * "MyResources" - and will be used as the bundle of last resort if a
  99  * specific locale is not supported. The family can then provide as
 100  * many locale-specific members as needed, for example a German one
 101  * named "MyResources_de".
 102  *
 103  * <P>
 104  * Each resource bundle in a family contains the same items, but the items have
 105  * been translated for the locale represented by that resource bundle.
 106  * For example, both "MyResources" and "MyResources_de" may have a
 107  * <code>String</code> that's used on a button for canceling operations.
 108  * In "MyResources" the <code>String</code> may contain "Cancel" and in
 109  * "MyResources_de" it may contain "Abbrechen".
 110  *
 111  * <P>
 112  * If there are different resources for different countries, you
 113  * can make specializations: for example, "MyResources_de_CH" contains objects for
 114  * the German language (de) in Switzerland (CH). If you want to only
 115  * modify some of the resources
 116  * in the specialization, you can do so.
 117  *
 118  * <P>
 119  * When your program needs a locale-specific object, it loads
 120  * the <code>ResourceBundle</code> class using the
 121  * {@link #getBundle(java.lang.String, java.util.Locale) getBundle}
 122  * method:
 123  * <blockquote>
 124  * <pre>
 125  * ResourceBundle myResources =
 126  *      ResourceBundle.getBundle("MyResources", currentLocale);
 127  * </pre>
 128  * </blockquote>
 129  *
 130  * <P>
 131  * Resource bundles contain key/value pairs. The keys uniquely
 132  * identify a locale-specific object in the bundle. Here's an
 133  * example of a <code>ListResourceBundle</code> that contains
 134  * two key/value pairs:
 135  * <blockquote>
 136  * <pre>
 137  * public class MyResources extends ListResourceBundle {
 138  *     protected Object[][] getContents() {
 139  *         return new Object[][] {
 140  *             // LOCALIZE THE SECOND STRING OF EACH ARRAY (e.g., "OK")
 141  *             {"OkKey", "OK"},
 142  *             {"CancelKey", "Cancel"},
 143  *             // END OF MATERIAL TO LOCALIZE
 144  *        };
 145  *     }
 146  * }
 147  * </pre>
 148  * </blockquote>
 149  * Keys are always <code>String</code>s.
 150  * In this example, the keys are "OkKey" and "CancelKey".
 151  * In the above example, the values
 152  * are also <code>String</code>s--"OK" and "Cancel"--but
 153  * they don't have to be. The values can be any type of object.
 154  *
 155  * <P>
 156  * You retrieve an object from resource bundle using the appropriate
 157  * getter method. Because "OkKey" and "CancelKey"
 158  * are both strings, you would use <code>getString</code> to retrieve them:
 159  * <blockquote>
 160  * <pre>
 161  * button1 = new Button(myResources.getString("OkKey"));
 162  * button2 = new Button(myResources.getString("CancelKey"));
 163  * </pre>
 164  * </blockquote>
 165  * The getter methods all require the key as an argument and return
 166  * the object if found. If the object is not found, the getter method
 167  * throws a <code>MissingResourceException</code>.
 168  *
 169  * <P>
 170  * Besides <code>getString</code>, <code>ResourceBundle</code> also provides
 171  * a method for getting string arrays, <code>getStringArray</code>,
 172  * as well as a generic <code>getObject</code> method for any other
 173  * type of object. When using <code>getObject</code>, you'll
 174  * have to cast the result to the appropriate type. For example:
 175  * <blockquote>
 176  * <pre>
 177  * int[] myIntegers = (int[]) myResources.getObject("intList");
 178  * </pre>
 179  * </blockquote>
 180  *
 181  * <P>
 182  * The Java Platform provides two subclasses of <code>ResourceBundle</code>,
 183  * <code>ListResourceBundle</code> and <code>PropertyResourceBundle</code>,
 184  * that provide a fairly simple way to create resources.
 185  * As you saw briefly in a previous example, <code>ListResourceBundle</code>
 186  * manages its resource as a list of key/value pairs.
 187  * <code>PropertyResourceBundle</code> uses a properties file to manage
 188  * its resources.
 189  *
 190  * <p>
 191  * If <code>ListResourceBundle</code> or <code>PropertyResourceBundle</code>
 192  * do not suit your needs, you can write your own <code>ResourceBundle</code>
 193  * subclass.  Your subclasses must override two methods: <code>handleGetObject</code>
 194  * and <code>getKeys()</code>.
 195  *
 196  * <p>
 197  * The implementation of a {@code ResourceBundle} subclass must be thread-safe
 198  * if it's simultaneously used by multiple threads. The default implementations
 199  * of the non-abstract methods in this class, and the methods in the direct
 200  * known concrete subclasses {@code ListResourceBundle} and
 201  * {@code PropertyResourceBundle} are thread-safe.
 202  *
 203  * <h3><a name="bundleprovider">Resource Bundles in Named Modules</a></h3>
 204  *
 205  * When resource bundles are deployed in named modules, the following
 206  * module-specific requirements and restrictions are applied.
 207  *
 208  * <ul>
 209  * <li>Code in a named module that calls {@link #getBundle(String, Locale)}
 210  * will locate resource bundles in the caller's module (<em>caller module</em>).</li>
 211  * <li>If resource bundles are deployed in named modules separate from
 212  * the caller module, those resource bundles need to be loaded from service
 213  * providers of {@link ResourceBundleProvider}. The caller module must declare
 214  * "{@code uses}" and the service interface name is the concatenation of the
 215  * base name of the bundles and the string "{@code Provider}". The
 216  * <em>bundle provider modules</em> containing resource bundles must
 217  * declare "{@code provides}" with the service interface name and
 218  * its implementation class name. For example, if the base name is
 219  * "{@code com.example.app.MyResources}", the caller module must declare
 220  * "{@code uses com.example.app.MyResourcesProvider;}" and a module containing resource
 221  * bundles must declare "{@code provides com.example.app.MyResourcesProvider
 222  * with com.example.app.internal.MyResourcesProviderImpl;}"
 223  * where {@code com.example.app.internal.MyResourcesProviderImpl} is an
 224  * implementation class of {@code com.example.app.MyResourcesProvider}.</li>
 225  * <li>If you want to use non-standard formats in named modules, such as XML,
 226  * {@link ResourceBundleProvider} needs to be used.</li>
 227  * <li>The {@code getBundle} method with a {@code ClassLoader} may not be able to
 228  * find resource bundles using the given {@code ClassLoader} in named modules.
 229  * The {@code getBundle} method with a {@code Module} can be used, instead.</li>
 230  * <li>{@code ResourceBundle.Control} is <em>not</em> supported in named modules.
 231  * If the {@code getBundle} method with a {@code ResourceBundle.Control} is called
 232  * in a named module, the method will throw an {@code UnsupportedOperationException}.
 233  * Any service providers of {@link ResourceBundleControlProvider} are ignored in
 234  * named modules.
 235  * </li>
 236  * </ul>
 237  *
 238  * <h3><a name="RBP_support">ResourceBundleProvider Service Providers</a></h3>
 239  *
 240  * The {@code getBundle} factory methods load service providers of
 241  * {@link ResourceBundleProvider}, if available, using {@link ServiceLoader}.
 242  * The service type is designated by {@code basename+"Provider"}. For
 243  * example, if the base name is "{@code com.example.app.MyResources}", the service
 244  * type is {@code com.example.app.MyResourcesProvider}.
 245  * <p>
 246  * In named modules, the loaded service providers for the given base name are
 247  * used to load resource bundles. If no service provider is available, or if
 248  * none of the service providers returns a resource bundle and the caller module
 249  * doesn't have its own service provider, the {@code getBundle} factory method
 250  * searches for resource bundles local to the caller module. The resource bundle
 251  * formats for local module searching are "java.class" and "java.properties".
 252  *
 253  * <h3>ResourceBundle.Control</h3>
 254  *
 255  * The {@link ResourceBundle.Control} class provides information necessary
 256  * to perform the bundle loading process by the <code>getBundle</code>
 257  * factory methods that take a <code>ResourceBundle.Control</code>
 258  * instance. You can implement your own subclass in order to enable
 259  * non-standard resource bundle formats, change the search strategy, or
 260  * define caching parameters. Refer to the descriptions of the class and the
 261  * {@link #getBundle(String, Locale, ClassLoader, Control) getBundle}
 262  * factory method for details.
 263  *
 264  * <p><a name="modify_default_behavior">For the {@code getBundle} factory</a>
 265  * methods that take no {@link Control} instance, their <a
 266  * href="#default_behavior"> default behavior</a> of resource bundle loading
 267  * can be modified with <em>installed</em> {@link
 268  * ResourceBundleControlProvider} implementations. Any installed providers are
 269  * detected at the {@code ResourceBundle} class loading time. If any of the
 270  * providers provides a {@link Control} for the given base name, that {@link
 271  * Control} will be used instead of the default {@link Control}. If there is
 272  * more than one service provider installed for supporting the same base name,
 273  * the first one returned from {@link ServiceLoader} will be used.
 274  *
 275  * <h3>Cache Management</h3>
 276  *
 277  * Resource bundle instances created by the <code>getBundle</code> factory
 278  * methods are cached by default, and the factory methods return the same
 279  * resource bundle instance multiple times if it has been
 280  * cached. <code>getBundle</code> clients may clear the cache, manage the
 281  * lifetime of cached resource bundle instances using time-to-live values,
 282  * or specify not to cache resource bundle instances. Refer to the
 283  * descriptions of the {@linkplain #getBundle(String, Locale, ClassLoader,
 284  * Control) <code>getBundle</code> factory method}, {@link
 285  * #clearCache(ClassLoader) clearCache}, {@link
 286  * Control#getTimeToLive(String, Locale)
 287  * ResourceBundle.Control.getTimeToLive}, and {@link
 288  * Control#needsReload(String, Locale, String, ClassLoader, ResourceBundle,
 289  * long) ResourceBundle.Control.needsReload} for details.
 290  *
 291  * <h3>Example</h3>
 292  *
 293  * The following is a very simple example of a <code>ResourceBundle</code>
 294  * subclass, <code>MyResources</code>, that manages two resources (for a larger number of
 295  * resources you would probably use a <code>Map</code>).
 296  * Notice that you don't need to supply a value if
 297  * a "parent-level" <code>ResourceBundle</code> handles the same
 298  * key with the same value (as for the okKey below).
 299  * <blockquote>
 300  * <pre>
 301  * // default (English language, United States)
 302  * public class MyResources extends ResourceBundle {
 303  *     public Object handleGetObject(String key) {
 304  *         if (key.equals("okKey")) return "Ok";
 305  *         if (key.equals("cancelKey")) return "Cancel";
 306  *         return null;
 307  *     }
 308  *
 309  *     public Enumeration&lt;String&gt; getKeys() {
 310  *         return Collections.enumeration(keySet());
 311  *     }
 312  *
 313  *     // Overrides handleKeySet() so that the getKeys() implementation
 314  *     // can rely on the keySet() value.
 315  *     protected Set&lt;String&gt; handleKeySet() {
 316  *         return new HashSet&lt;String&gt;(Arrays.asList("okKey", "cancelKey"));
 317  *     }
 318  * }
 319  *
 320  * // German language
 321  * public class MyResources_de extends MyResources {
 322  *     public Object handleGetObject(String key) {
 323  *         // don't need okKey, since parent level handles it.
 324  *         if (key.equals("cancelKey")) return "Abbrechen";
 325  *         return null;
 326  *     }
 327  *
 328  *     protected Set&lt;String&gt; handleKeySet() {
 329  *         return new HashSet&lt;String&gt;(Arrays.asList("cancelKey"));
 330  *     }
 331  * }
 332  * </pre>
 333  * </blockquote>
 334  * You do not have to restrict yourself to using a single family of
 335  * <code>ResourceBundle</code>s. For example, you could have a set of bundles for
 336  * exception messages, <code>ExceptionResources</code>
 337  * (<code>ExceptionResources_fr</code>, <code>ExceptionResources_de</code>, ...),
 338  * and one for widgets, <code>WidgetResource</code> (<code>WidgetResources_fr</code>,
 339  * <code>WidgetResources_de</code>, ...); breaking up the resources however you like.
 340  *
 341  * @see ListResourceBundle
 342  * @see PropertyResourceBundle
 343  * @see MissingResourceException
 344  * @see ResourceBundleProvider
 345  * @since 1.1
 346  */
 347 public abstract class ResourceBundle {
 348 
 349     /** initial size of the bundle cache */
 350     private static final int INITIAL_CACHE_SIZE = 32;
 351 
 352     static {
 353         SharedSecrets.setJavaUtilResourceBundleAccess(
 354             new JavaUtilResourceBundleAccess() {
 355                 @Override
 356                 public void setParent(ResourceBundle bundle,
 357                                       ResourceBundle parent) {
 358                     bundle.setParent(parent);
 359                 }
 360 
 361                 @Override
 362                 public ResourceBundle getParent(ResourceBundle bundle) {
 363                     return bundle.parent;
 364                 }
 365 
 366                 @Override
 367                 public void setLocale(ResourceBundle bundle, Locale locale) {
 368                     bundle.locale = locale;
 369                 }
 370 
 371                 @Override
 372                 public void setName(ResourceBundle bundle, String name) {
 373                     bundle.name = name;
 374                 }
 375             });
 376     }
 377 
 378     /** constant indicating that no resource bundle exists */
 379     private static final ResourceBundle NONEXISTENT_BUNDLE = new ResourceBundle() {
 380             public Enumeration<String> getKeys() { return null; }
 381             protected Object handleGetObject(String key) { return null; }
 382             public String toString() { return "NONEXISTENT_BUNDLE"; }
 383         };
 384 
 385 
 386     /**
 387      * The cache is a map from cache keys (with bundle base name, locale, and
 388      * class loader) to either a resource bundle or NONEXISTENT_BUNDLE wrapped by a
 389      * BundleReference.
 390      *
 391      * The cache is a ConcurrentMap, allowing the cache to be searched
 392      * concurrently by multiple threads.  This will also allow the cache keys
 393      * to be reclaimed along with the ClassLoaders they reference.
 394      *
 395      * This variable would be better named "cache", but we keep the old
 396      * name for compatibility with some workarounds for bug 4212439.
 397      */
 398     private static final ConcurrentMap<CacheKey, BundleReference> cacheList
 399         = new ConcurrentHashMap<>(INITIAL_CACHE_SIZE);
 400 
 401     /**
 402      * Queue for reference objects referring to class loaders or bundles.
 403      */
 404     private static final ReferenceQueue<Object> referenceQueue = new ReferenceQueue<>();
 405 
 406     /**
 407      * Returns the base name of this bundle, if known, or {@code null} if unknown.
 408      *
 409      * If not null, then this is the value of the {@code baseName} parameter
 410      * that was passed to the {@code ResourceBundle.getBundle(...)} method
 411      * when the resource bundle was loaded.
 412      *
 413      * @return The base name of the resource bundle, as provided to and expected
 414      * by the {@code ResourceBundle.getBundle(...)} methods.
 415      *
 416      * @see #getBundle(java.lang.String, java.util.Locale, java.lang.ClassLoader)
 417      *
 418      * @since 1.8
 419      */
 420     public String getBaseBundleName() {
 421         return name;
 422     }
 423 
 424     /**
 425      * The parent bundle of this bundle.
 426      * The parent bundle is searched by {@link #getObject getObject}
 427      * when this bundle does not contain a particular resource.
 428      */
 429     protected ResourceBundle parent = null;
 430 
 431     /**
 432      * The locale for this bundle.
 433      */
 434     private Locale locale = null;
 435 
 436     /**
 437      * The base bundle name for this bundle.
 438      */
 439     private String name;
 440 
 441     /**
 442      * The flag indicating this bundle has expired in the cache.
 443      */
 444     private volatile boolean expired;
 445 
 446     /**
 447      * The back link to the cache key. null if this bundle isn't in
 448      * the cache (yet) or has expired.
 449      */
 450     private volatile CacheKey cacheKey;
 451 
 452     /**
 453      * A Set of the keys contained only in this ResourceBundle.
 454      */
 455     private volatile Set<String> keySet;
 456 
 457     private static final List<ResourceBundleControlProvider> providers;
 458 
 459     static {
 460         List<ResourceBundleControlProvider> list = null;
 461         ServiceLoader<ResourceBundleControlProvider> serviceLoaders
 462                 = ServiceLoader.loadInstalled(ResourceBundleControlProvider.class);
 463         for (ResourceBundleControlProvider provider : serviceLoaders) {
 464             if (list == null) {
 465                 list = new ArrayList<>();
 466             }
 467             list.add(provider);
 468         }
 469         providers = list;
 470     }
 471 
 472     /**
 473      * Sole constructor.  (For invocation by subclass constructors, typically
 474      * implicit.)
 475      */
 476     public ResourceBundle() {
 477     }
 478 
 479     /**
 480      * Gets a string for the given key from this resource bundle or one of its parents.
 481      * Calling this method is equivalent to calling
 482      * <blockquote>
 483      * <code>(String) {@link #getObject(java.lang.String) getObject}(key)</code>.
 484      * </blockquote>
 485      *
 486      * @param key the key for the desired string
 487      * @exception NullPointerException if <code>key</code> is <code>null</code>
 488      * @exception MissingResourceException if no object for the given key can be found
 489      * @exception ClassCastException if the object found for the given key is not a string
 490      * @return the string for the given key
 491      */
 492     public final String getString(String key) {
 493         return (String) getObject(key);
 494     }
 495 
 496     /**
 497      * Gets a string array for the given key from this resource bundle or one of its parents.
 498      * Calling this method is equivalent to calling
 499      * <blockquote>
 500      * <code>(String[]) {@link #getObject(java.lang.String) getObject}(key)</code>.
 501      * </blockquote>
 502      *
 503      * @param key the key for the desired string array
 504      * @exception NullPointerException if <code>key</code> is <code>null</code>
 505      * @exception MissingResourceException if no object for the given key can be found
 506      * @exception ClassCastException if the object found for the given key is not a string array
 507      * @return the string array for the given key
 508      */
 509     public final String[] getStringArray(String key) {
 510         return (String[]) getObject(key);
 511     }
 512 
 513     /**
 514      * Gets an object for the given key from this resource bundle or one of its parents.
 515      * This method first tries to obtain the object from this resource bundle using
 516      * {@link #handleGetObject(java.lang.String) handleGetObject}.
 517      * If not successful, and the parent resource bundle is not null,
 518      * it calls the parent's <code>getObject</code> method.
 519      * If still not successful, it throws a MissingResourceException.
 520      *
 521      * @param key the key for the desired object
 522      * @exception NullPointerException if <code>key</code> is <code>null</code>
 523      * @exception MissingResourceException if no object for the given key can be found
 524      * @return the object for the given key
 525      */
 526     public final Object getObject(String key) {
 527         Object obj = handleGetObject(key);
 528         if (obj == null) {
 529             if (parent != null) {
 530                 obj = parent.getObject(key);
 531             }
 532             if (obj == null) {
 533                 throw new MissingResourceException("Can't find resource for bundle "
 534                                                    +this.getClass().getName()
 535                                                    +", key "+key,
 536                                                    this.getClass().getName(),
 537                                                    key);
 538             }
 539         }
 540         return obj;
 541     }
 542 
 543     /**
 544      * Returns the locale of this resource bundle. This method can be used after a
 545      * call to getBundle() to determine whether the resource bundle returned really
 546      * corresponds to the requested locale or is a fallback.
 547      *
 548      * @return the locale of this resource bundle
 549      */
 550     public Locale getLocale() {
 551         return locale;
 552     }
 553 
 554     /*
 555      * Automatic determination of the ClassLoader to be used to load
 556      * resources on behalf of the client.
 557      */
 558     private static ClassLoader getLoader(Class<?> caller) {
 559         ClassLoader cl = caller == null ? null : caller.getClassLoader();
 560         if (cl == null) {
 561             // When the caller's loader is the boot class loader, cl is null
 562             // here. In that case, ClassLoader.getSystemClassLoader() may
 563             // return the same class loader that the application is
 564             // using. We therefore use a wrapper ClassLoader to create a
 565             // separate scope for bundles loaded on behalf of the Java
 566             // runtime so that these bundles cannot be returned from the
 567             // cache to the application (5048280).
 568             cl = RBClassLoader.INSTANCE;
 569         }
 570         return cl;
 571     }
 572 
 573     private static ClassLoader getLoader(Module module) {
 574         PrivilegedAction<ClassLoader> pa = module::getClassLoader;
 575         return AccessController.doPrivileged(pa);
 576     }
 577 
 578     /**
 579      * A wrapper of ClassLoader.getSystemClassLoader().
 580      */
 581     private static class RBClassLoader extends ClassLoader {
 582         private static final RBClassLoader INSTANCE = AccessController.doPrivileged(
 583                     new PrivilegedAction<RBClassLoader>() {
 584                         public RBClassLoader run() {
 585                             return new RBClassLoader();
 586                         }
 587                     });
 588         private RBClassLoader() {
 589         }
 590         public Class<?> loadClass(String name) throws ClassNotFoundException {
 591             ClassLoader loader = ClassLoader.getSystemClassLoader();
 592             if (loader != null) {
 593                 return loader.loadClass(name);
 594             }
 595             return Class.forName(name);
 596         }
 597         public URL getResource(String name) {
 598             ClassLoader loader = ClassLoader.getSystemClassLoader();
 599             if (loader != null) {
 600                 return loader.getResource(name);
 601             }
 602             return ClassLoader.getSystemResource(name);
 603         }
 604         public InputStream getResourceAsStream(String name) {
 605             ClassLoader loader = ClassLoader.getSystemClassLoader();
 606             if (loader != null) {
 607                 return loader.getResourceAsStream(name);
 608             }
 609             return ClassLoader.getSystemResourceAsStream(name);
 610         }
 611     }
 612 
 613     /**
 614      * Sets the parent bundle of this bundle.
 615      * The parent bundle is searched by {@link #getObject getObject}
 616      * when this bundle does not contain a particular resource.
 617      *
 618      * @param parent this bundle's parent bundle.
 619      */
 620     protected void setParent(ResourceBundle parent) {
 621         assert parent != NONEXISTENT_BUNDLE;
 622         this.parent = parent;
 623     }
 624 
 625     /**
 626      * Key used for cached resource bundles.  The key checks the base
 627      * name, the locale, the class loader, and the caller module
 628      * to determine if the resource is a match to the requested one.
 629      * The loader may be null, but the base name, the locale and
 630      * module must have a non-null value.
 631      */
 632     private static class CacheKey implements Cloneable {
 633         // These four are the actual keys for lookup in Map.
 634         private String name;
 635         private Locale locale;
 636         private KeyElementReference<ClassLoader> loaderRef;
 637         private KeyElementReference<Module> moduleRef;
 638 
 639 
 640         // bundle format which is necessary for calling
 641         // Control.needsReload().
 642         private String format;
 643 
 644         // These time values are in CacheKey so that NONEXISTENT_BUNDLE
 645         // doesn't need to be cloned for caching.
 646 
 647         // The time when the bundle has been loaded
 648         private volatile long loadTime;
 649 
 650         // The time when the bundle expires in the cache, or either
 651         // Control.TTL_DONT_CACHE or Control.TTL_NO_EXPIRATION_CONTROL.
 652         private volatile long expirationTime;
 653 
 654         // Placeholder for an error report by a Throwable
 655         private Throwable cause;
 656 
 657         // Hash code value cache to avoid recalculating the hash code
 658         // of this instance.
 659         private int hashCodeCache;
 660 
 661         // ResourceBundleProviders for loading ResourceBundles
 662         private ServiceLoader<ResourceBundleProvider> providers;
 663         private boolean providersChecked;
 664 
 665         // Boolean.TRUE if the factory method caller provides a ResourceBundleProvier.
 666         private Boolean callerHasProvider;
 667 
 668         CacheKey(String baseName, Locale locale, ClassLoader loader, Module module) {
 669             Objects.requireNonNull(module);
 670 
 671             this.name = baseName;
 672             this.locale = locale;
 673             if (loader == null) {
 674                 this.loaderRef = null;
 675             } else {
 676                 this.loaderRef = new KeyElementReference<>(loader, referenceQueue, this);
 677             }
 678             this.moduleRef = new KeyElementReference<>(module, referenceQueue, this);
 679             calculateHashCode();
 680         }
 681 
 682         String getName() {
 683             return name;
 684         }
 685 
 686         CacheKey setName(String baseName) {
 687             if (!this.name.equals(baseName)) {
 688                 this.name = baseName;
 689                 calculateHashCode();
 690             }
 691             return this;
 692         }
 693 
 694         Locale getLocale() {
 695             return locale;
 696         }
 697 
 698         CacheKey setLocale(Locale locale) {
 699             if (!this.locale.equals(locale)) {
 700                 this.locale = locale;
 701                 calculateHashCode();
 702             }
 703             return this;
 704         }
 705 
 706         ClassLoader getLoader() {
 707             return (loaderRef != null) ? loaderRef.get() : null;
 708         }
 709 
 710         Module getModule() {
 711             return moduleRef.get();
 712         }
 713 
 714         ServiceLoader<ResourceBundleProvider> getProviders() {
 715             if (!providersChecked) {
 716                 providers = getServiceLoader(getModule(), name);
 717                 providersChecked = true;
 718             }
 719             return providers;
 720         }
 721 
 722         boolean hasProviders() {
 723             return getProviders() != null;
 724         }
 725 
 726         boolean callerHasProvider() {
 727             return callerHasProvider == Boolean.TRUE;
 728         }
 729 
 730         @Override
 731         public boolean equals(Object other) {
 732             if (this == other) {
 733                 return true;
 734             }
 735             try {
 736                 final CacheKey otherEntry = (CacheKey)other;
 737                 //quick check to see if they are not equal
 738                 if (hashCodeCache != otherEntry.hashCodeCache) {
 739                     return false;
 740                 }
 741                 //are the names the same?
 742                 if (!name.equals(otherEntry.name)) {
 743                     return false;
 744                 }
 745                 // are the locales the same?
 746                 if (!locale.equals(otherEntry.locale)) {
 747                     return false;
 748                 }
 749                 //are refs (both non-null) or (both null)?
 750                 if (loaderRef == null) {
 751                     return otherEntry.loaderRef == null;
 752                 }
 753                 ClassLoader loader = getLoader();
 754                 Module module = getModule();
 755                 return (otherEntry.loaderRef != null)
 756                         // with a null reference we can no longer find
 757                         // out which class loader or module was referenced; so
 758                         // treat it as unequal
 759                         && (loader != null)
 760                         && (loader == otherEntry.getLoader())
 761                         && (module != null)
 762                         && (module.equals(otherEntry.getModule()));
 763             } catch (NullPointerException | ClassCastException e) {
 764             }
 765             return false;
 766         }
 767 
 768         @Override
 769         public int hashCode() {
 770             return hashCodeCache;
 771         }
 772 
 773         private void calculateHashCode() {
 774             hashCodeCache = name.hashCode() << 3;
 775             hashCodeCache ^= locale.hashCode();
 776             ClassLoader loader = getLoader();
 777             if (loader != null) {
 778                 hashCodeCache ^= loader.hashCode();
 779             }
 780             Module module = getModule();
 781             if (module != null) {
 782                 hashCodeCache ^= module.hashCode();
 783             }
 784         }
 785 
 786         @Override
 787         public Object clone() {
 788             try {
 789                 CacheKey clone = (CacheKey) super.clone();
 790                 if (loaderRef != null) {
 791                     clone.loaderRef = new KeyElementReference<>(getLoader(),
 792                                                                 referenceQueue, clone);
 793                 }
 794                 clone.moduleRef = new KeyElementReference<>(getModule(),
 795                                                             referenceQueue, clone);
 796                 // Clear the reference to ResourceBundleProviders and the flag
 797                 clone.providers = null;
 798                 clone.providersChecked = false;
 799                 // Clear the reference to a Throwable
 800                 clone.cause = null;
 801                 // Clear callerHasProvider
 802                 clone.callerHasProvider = null;
 803                 return clone;
 804             } catch (CloneNotSupportedException e) {
 805                 //this should never happen
 806                 throw new InternalError(e);
 807             }
 808         }
 809 
 810         String getFormat() {
 811             return format;
 812         }
 813 
 814         void setFormat(String format) {
 815             this.format = format;
 816         }
 817 
 818         private void setCause(Throwable cause) {
 819             if (this.cause == null) {
 820                 this.cause = cause;
 821             } else {
 822                 // Override the cause if the previous one is
 823                 // ClassNotFoundException.
 824                 if (this.cause instanceof ClassNotFoundException) {
 825                     this.cause = cause;
 826                 }
 827             }
 828         }
 829 
 830         private Throwable getCause() {
 831             return cause;
 832         }
 833 
 834         @Override
 835         public String toString() {
 836             String l = locale.toString();
 837             if (l.length() == 0) {
 838                 if (locale.getVariant().length() != 0) {
 839                     l = "__" + locale.getVariant();
 840                 } else {
 841                     l = "\"\"";
 842                 }
 843             }
 844             return "CacheKey[" + name + ", lc=" + l + ", ldr=" + getLoader()
 845                 + "(format=" + format + ")]";
 846         }
 847     }
 848 
 849     /**
 850      * The common interface to get a CacheKey in LoaderReference and
 851      * BundleReference.
 852      */
 853     private static interface CacheKeyReference {
 854         public CacheKey getCacheKey();
 855     }
 856 
 857     /**
 858      * References to a CacheKey element as a WeakReference so that it can be
 859      * garbage collected when nobody else is using it.
 860      */
 861     private static class KeyElementReference<T> extends WeakReference<T>
 862                                                 implements CacheKeyReference {
 863         private final CacheKey cacheKey;
 864 
 865         KeyElementReference(T referent, ReferenceQueue<Object> q, CacheKey key) {
 866             super(referent, q);
 867             cacheKey = key;
 868         }
 869 
 870         @Override
 871         public CacheKey getCacheKey() {
 872             return cacheKey;
 873         }
 874     }
 875 
 876     /**
 877      * References to bundles are soft references so that they can be garbage
 878      * collected when they have no hard references.
 879      */
 880     private static class BundleReference extends SoftReference<ResourceBundle>
 881                                          implements CacheKeyReference {
 882         private final CacheKey cacheKey;
 883 
 884         BundleReference(ResourceBundle referent, ReferenceQueue<Object> q, CacheKey key) {
 885             super(referent, q);
 886             cacheKey = key;
 887         }
 888 
 889         @Override
 890         public CacheKey getCacheKey() {
 891             return cacheKey;
 892         }
 893     }
 894 
 895     /**
 896      * Gets a resource bundle using the specified base name, the default locale,
 897      * and the caller's class loader. Calling this method is equivalent to calling
 898      * <blockquote>
 899      * <code>getBundle(baseName, Locale.getDefault(), this.getClass().getClassLoader())</code>,
 900      * </blockquote>
 901      * except that <code>getClassLoader()</code> is run with the security
 902      * privileges of <code>ResourceBundle</code>.
 903      * See {@link #getBundle(String, Locale, ClassLoader) getBundle}
 904      * for a complete description of the search and instantiation strategy.
 905      *
 906      * @param baseName the base name of the resource bundle, a fully qualified class name
 907      * @exception java.lang.NullPointerException
 908      *     if <code>baseName</code> is <code>null</code>
 909      * @exception MissingResourceException
 910      *     if no resource bundle for the specified base name can be found
 911      * @return a resource bundle for the given base name and the default locale
 912      */
 913     @CallerSensitive
 914     public static final ResourceBundle getBundle(String baseName)
 915     {
 916         Class<?> caller = Reflection.getCallerClass();
 917         return getBundleImpl(baseName, Locale.getDefault(),
 918                              caller, getDefaultControl(caller, baseName));
 919     }
 920 
 921     /**
 922      * Returns a resource bundle using the specified base name, the
 923      * default locale and the specified control. Calling this method
 924      * is equivalent to calling
 925      * <pre>
 926      * getBundle(baseName, Locale.getDefault(),
 927      *           this.getClass().getClassLoader(), control),
 928      * </pre>
 929      * except that <code>getClassLoader()</code> is run with the security
 930      * privileges of <code>ResourceBundle</code>.  See {@link
 931      * #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
 932      * complete description of the resource bundle loading process with a
 933      * <code>ResourceBundle.Control</code>.
 934      *
 935      * @param baseName
 936      *        the base name of the resource bundle, a fully qualified class
 937      *        name
 938      * @param control
 939      *        the control which gives information for the resource bundle
 940      *        loading process
 941      * @return a resource bundle for the given base name and the default locale
 942      * @throws NullPointerException
 943      *         if <code>baseName</code> or <code>control</code> is
 944      *         <code>null</code>
 945      * @throws MissingResourceException
 946      *         if no resource bundle for the specified base name can be found
 947      * @throws IllegalArgumentException
 948      *         if the given <code>control</code> doesn't perform properly
 949      *         (e.g., <code>control.getCandidateLocales</code> returns null.)
 950      *         Note that validation of <code>control</code> is performed as
 951      *         needed.
 952      * @throws UnsupportedOperationException
 953      *         if this method is called in a named module
 954      * @since 1.6
 955      */
 956     @CallerSensitive
 957     public static final ResourceBundle getBundle(String baseName,
 958                                                  Control control) {
 959         Class<?> caller = Reflection.getCallerClass();
 960         Locale targetLocale = Locale.getDefault();
 961         checkNamedModule(caller);
 962         return getBundleImpl(baseName, targetLocale, caller, control);
 963     }
 964 
 965     /**
 966      * Gets a resource bundle using the specified base name and locale,
 967      * and the caller's class loader. Calling this method is equivalent to calling
 968      * <blockquote>
 969      * <code>getBundle(baseName, locale, this.getClass().getClassLoader())</code>,
 970      * </blockquote>
 971      * except that <code>getClassLoader()</code> is run with the security
 972      * privileges of <code>ResourceBundle</code>.
 973      * See {@link #getBundle(String, Locale, ClassLoader) getBundle}
 974      * for a complete description of the search and instantiation strategy.
 975      *
 976      * @param baseName
 977      *        the base name of the resource bundle, a fully qualified class name
 978      * @param locale
 979      *        the locale for which a resource bundle is desired
 980      * @exception NullPointerException
 981      *        if <code>baseName</code> or <code>locale</code> is <code>null</code>
 982      * @exception MissingResourceException
 983      *        if no resource bundle for the specified base name can be found
 984      * @return a resource bundle for the given base name and locale
 985      */
 986     @CallerSensitive
 987     public static final ResourceBundle getBundle(String baseName,
 988                                                  Locale locale)
 989     {
 990         Class<?> caller = Reflection.getCallerClass();
 991         return getBundleImpl(baseName, locale,
 992                              caller, getDefaultControl(caller, baseName));
 993     }
 994 
 995     /**
 996      * Gets a resource bundle using the specified base name and the default locale
 997      * on behalf of the specified module. This method is equivalent to calling
 998      * <blockquote>
 999      * <code>getBundle(baseName, Locale.getDefault(), module)</code>
1000      * </blockquote>
1001      *
1002      * @param baseName the base name of the resource bundle,
1003      *                 a fully qualified class name
1004      * @param module   the module for which the resource bundle is searched
1005      * @throws NullPointerException
1006      *         if {@code baseName} or {@code module} is {@code null}
1007      * @throws SecurityException
1008      *         if a security manager exists and the caller is not the specified
1009      *         module and doesn't have {@code RuntimePermission("getClassLoader")}
1010      * @throws MissingResourceException
1011      *         if no resource bundle for the specified base name can be found in the
1012      *         specified module
1013      * @return a resource bundle for the given base name and the default locale
1014      * @since 9
1015      * @see ResourceBundleProvider
1016      */
1017     @CallerSensitive
1018     public static ResourceBundle getBundle(String baseName, Module module) {
1019         return getBundleFromModule(Reflection.getCallerClass(), module, baseName,
1020                                    Locale.getDefault(), Control.INSTANCE);
1021     }
1022 
1023     /**
1024      * Gets a resource bundle using the specified base name and locale
1025      * on behalf of the specified module.
1026      *
1027      * <p>
1028      * If the given {@code module} is a named module, this method will
1029      * load the service providers for {@link java.util.spi.ResourceBundleProvider}
1030      * and also resource bundles local in the given module (refer to the
1031      * <a href="#bundleprovider">Resource Bundles in Named Modules</a> section
1032      * for details).
1033      *
1034      * <p>
1035      * If the given {@code module} is an unnamed module, then this method is
1036      * equivalent to calling {@link #getBundle(String, Locale, ClassLoader)
1037      * getBundle(baseName, targetLocale, module.getClassLoader()} to load
1038      * resource bundles that are in unnamed modules visible to the
1039      * class loader of the given unnamed module.  It will not find resource
1040      * bundles from named modules.
1041      *
1042      * @param baseName the base name of the resource bundle,
1043      *                 a fully qualified class name
1044      * @param targetLocale the locale for which a resource bundle is desired
1045      * @param module   the module for which the resource bundle is searched
1046      * @throws NullPointerException
1047      *         if {@code baseName}, {@code targetLocale}, or {@code module} is
1048      *         {@code null}
1049      * @throws SecurityException
1050      *         if a security manager exists and the caller is not the specified
1051      *         module and doesn't have {@code RuntimePermission("getClassLoader")}
1052      * @throws MissingResourceException
1053      *         if no resource bundle for the specified base name and locale can
1054      *         be found in the specified {@code module}
1055      * @return a resource bundle for the given base name and locale in the module
1056      * @since 9
1057      */
1058     @CallerSensitive
1059     public static ResourceBundle getBundle(String baseName, Locale targetLocale, Module module) {
1060         return getBundleFromModule(Reflection.getCallerClass(), module, baseName, targetLocale,
1061                                    Control.INSTANCE);
1062     }
1063 
1064     /**
1065      * Returns a resource bundle using the specified base name, target
1066      * locale and control, and the caller's class loader. Calling this
1067      * method is equivalent to calling
1068      * <pre>
1069      * getBundle(baseName, targetLocale, this.getClass().getClassLoader(),
1070      *           control),
1071      * </pre>
1072      * except that <code>getClassLoader()</code> is run with the security
1073      * privileges of <code>ResourceBundle</code>.  See {@link
1074      * #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
1075      * complete description of the resource bundle loading process with a
1076      * <code>ResourceBundle.Control</code>.
1077      *
1078      * @param baseName
1079      *        the base name of the resource bundle, a fully qualified
1080      *        class name
1081      * @param targetLocale
1082      *        the locale for which a resource bundle is desired
1083      * @param control
1084      *        the control which gives information for the resource
1085      *        bundle loading process
1086      * @return a resource bundle for the given base name and a
1087      *         <code>Locale</code> in <code>locales</code>
1088      * @throws NullPointerException
1089      *         if <code>baseName</code>, <code>locales</code> or
1090      *         <code>control</code> is <code>null</code>
1091      * @throws MissingResourceException
1092      *         if no resource bundle for the specified base name in any
1093      *         of the <code>locales</code> can be found.
1094      * @throws IllegalArgumentException
1095      *         if the given <code>control</code> doesn't perform properly
1096      *         (e.g., <code>control.getCandidateLocales</code> returns null.)
1097      *         Note that validation of <code>control</code> is performed as
1098      *         needed.
1099      * @throws UnsupportedOperationException
1100      *         if this method is called in a named module
1101      * @since 1.6
1102      */
1103     @CallerSensitive
1104     public static final ResourceBundle getBundle(String baseName, Locale targetLocale,
1105                                                  Control control) {
1106         Class<?> caller = Reflection.getCallerClass();
1107         checkNamedModule(caller);
1108         return getBundleImpl(baseName, targetLocale, caller, control);
1109     }
1110 
1111     /**
1112      * Gets a resource bundle using the specified base name, locale, and class
1113      * loader.
1114      *
1115      * <p>This method behaves the same as calling
1116      * {@link #getBundle(String, Locale, ClassLoader, Control)} passing a
1117      * default instance of {@link Control} unless another {@link Control} is
1118      * provided with the {@link ResourceBundleControlProvider} SPI. Refer to the
1119      * description of <a href="#modify_default_behavior">modifying the default
1120      * behavior</a>.
1121      *
1122      * <p><a name="default_behavior">The following describes the default
1123      * behavior</a>.
1124      *
1125      * <p>
1126      * Resource bundles in a named module are private to that module.  If
1127      * the caller is in a named module, this method will find resource bundles
1128      * from the service providers of {@link java.util.spi.ResourceBundleProvider}
1129      * and also find resource bundles private to the caller's module.
1130      * If the caller is in a named module and the given {@code loader} is
1131      * different than the caller's class loader, or if the caller is not in
1132      * a named module, this method will not find resource bundles from named
1133      * modules.
1134      *
1135      * <p><code>getBundle</code> uses the base name, the specified locale, and
1136      * the default locale (obtained from {@link java.util.Locale#getDefault()
1137      * Locale.getDefault}) to generate a sequence of <a
1138      * name="candidates"><em>candidate bundle names</em></a>.  If the specified
1139      * locale's language, script, country, and variant are all empty strings,
1140      * then the base name is the only candidate bundle name.  Otherwise, a list
1141      * of candidate locales is generated from the attribute values of the
1142      * specified locale (language, script, country and variant) and appended to
1143      * the base name.  Typically, this will look like the following:
1144      *
1145      * <pre>
1146      *     baseName + "_" + language + "_" + script + "_" + country + "_" + variant
1147      *     baseName + "_" + language + "_" + script + "_" + country
1148      *     baseName + "_" + language + "_" + script
1149      *     baseName + "_" + language + "_" + country + "_" + variant
1150      *     baseName + "_" + language + "_" + country
1151      *     baseName + "_" + language
1152      * </pre>
1153      *
1154      * <p>Candidate bundle names where the final component is an empty string
1155      * are omitted, along with the underscore.  For example, if country is an
1156      * empty string, the second and the fifth candidate bundle names above
1157      * would be omitted.  Also, if script is an empty string, the candidate names
1158      * including script are omitted.  For example, a locale with language "de"
1159      * and variant "JAVA" will produce candidate names with base name
1160      * "MyResource" below.
1161      *
1162      * <pre>
1163      *     MyResource_de__JAVA
1164      *     MyResource_de
1165      * </pre>
1166      *
1167      * In the case that the variant contains one or more underscores ('_'), a
1168      * sequence of bundle names generated by truncating the last underscore and
1169      * the part following it is inserted after a candidate bundle name with the
1170      * original variant.  For example, for a locale with language "en", script
1171      * "Latn, country "US" and variant "WINDOWS_VISTA", and bundle base name
1172      * "MyResource", the list of candidate bundle names below is generated:
1173      *
1174      * <pre>
1175      * MyResource_en_Latn_US_WINDOWS_VISTA
1176      * MyResource_en_Latn_US_WINDOWS
1177      * MyResource_en_Latn_US
1178      * MyResource_en_Latn
1179      * MyResource_en_US_WINDOWS_VISTA
1180      * MyResource_en_US_WINDOWS
1181      * MyResource_en_US
1182      * MyResource_en
1183      * </pre>
1184      *
1185      * <blockquote><b>Note:</b> For some <code>Locale</code>s, the list of
1186      * candidate bundle names contains extra names, or the order of bundle names
1187      * is slightly modified.  See the description of the default implementation
1188      * of {@link Control#getCandidateLocales(String, Locale)
1189      * getCandidateLocales} for details.</blockquote>
1190      *
1191      * <p><code>getBundle</code> then iterates over the candidate bundle names
1192      * to find the first one for which it can <em>instantiate</em> an actual
1193      * resource bundle. It uses the default controls' {@link Control#getFormats
1194      * getFormats} method, which generates two bundle names for each generated
1195      * name, the first a class name and the second a properties file name. For
1196      * each candidate bundle name, it attempts to create a resource bundle:
1197      *
1198      * <ul><li>First, it attempts to load a class using the generated class name.
1199      * If such a class can be found and loaded using the specified class
1200      * loader, is assignment compatible with ResourceBundle, is accessible from
1201      * ResourceBundle, and can be instantiated, <code>getBundle</code> creates a
1202      * new instance of this class and uses it as the <em>result resource
1203      * bundle</em>.
1204      *
1205      * <li>Otherwise, <code>getBundle</code> attempts to locate a property
1206      * resource file using the generated properties file name.  It generates a
1207      * path name from the candidate bundle name by replacing all "." characters
1208      * with "/" and appending the string ".properties".  It attempts to find a
1209      * "resource" with this name using {@link
1210      * java.lang.ClassLoader#getResource(java.lang.String)
1211      * ClassLoader.getResource}.  (Note that a "resource" in the sense of
1212      * <code>getResource</code> has nothing to do with the contents of a
1213      * resource bundle, it is just a container of data, such as a file.)  If it
1214      * finds a "resource", it attempts to create a new {@link
1215      * PropertyResourceBundle} instance from its contents.  If successful, this
1216      * instance becomes the <em>result resource bundle</em>.  </ul>
1217      *
1218      * <p>This continues until a result resource bundle is instantiated or the
1219      * list of candidate bundle names is exhausted.  If no matching resource
1220      * bundle is found, the default control's {@link Control#getFallbackLocale
1221      * getFallbackLocale} method is called, which returns the current default
1222      * locale.  A new sequence of candidate locale names is generated using this
1223      * locale and searched again, as above.
1224      *
1225      * <p>If still no result bundle is found, the base name alone is looked up. If
1226      * this still fails, a <code>MissingResourceException</code> is thrown.
1227      *
1228      * <p><a name="parent_chain"> Once a result resource bundle has been found,
1229      * its <em>parent chain</em> is instantiated</a>.  If the result bundle already
1230      * has a parent (perhaps because it was returned from a cache) the chain is
1231      * complete.
1232      *
1233      * <p>Otherwise, <code>getBundle</code> examines the remainder of the
1234      * candidate locale list that was used during the pass that generated the
1235      * result resource bundle.  (As before, candidate bundle names where the
1236      * final component is an empty string are omitted.)  When it comes to the
1237      * end of the candidate list, it tries the plain bundle name.  With each of the
1238      * candidate bundle names it attempts to instantiate a resource bundle (first
1239      * looking for a class and then a properties file, as described above).
1240      *
1241      * <p>Whenever it succeeds, it calls the previously instantiated resource
1242      * bundle's {@link #setParent(java.util.ResourceBundle) setParent} method
1243      * with the new resource bundle.  This continues until the list of names
1244      * is exhausted or the current bundle already has a non-null parent.
1245      *
1246      * <p>Once the parent chain is complete, the bundle is returned.
1247      *
1248      * <p><b>Note:</b> <code>getBundle</code> caches instantiated resource
1249      * bundles and might return the same resource bundle instance multiple times.
1250      *
1251      * <p><b>Note:</b>The <code>baseName</code> argument should be a fully
1252      * qualified class name. However, for compatibility with earlier versions,
1253      * Sun's Java SE Runtime Environments do not verify this, and so it is
1254      * possible to access <code>PropertyResourceBundle</code>s by specifying a
1255      * path name (using "/") instead of a fully qualified class name (using
1256      * ".").
1257      *
1258      * <p><a name="default_behavior_example">
1259      * <strong>Example:</strong></a>
1260      * <p>
1261      * The following class and property files are provided:
1262      * <pre>
1263      *     MyResources.class
1264      *     MyResources.properties
1265      *     MyResources_fr.properties
1266      *     MyResources_fr_CH.class
1267      *     MyResources_fr_CH.properties
1268      *     MyResources_en.properties
1269      *     MyResources_es_ES.class
1270      * </pre>
1271      *
1272      * The contents of all files are valid (that is, public non-abstract
1273      * subclasses of <code>ResourceBundle</code> for the ".class" files,
1274      * syntactically correct ".properties" files).  The default locale is
1275      * <code>Locale("en", "GB")</code>.
1276      *
1277      * <p>Calling <code>getBundle</code> with the locale arguments below will
1278      * instantiate resource bundles as follows:
1279      *
1280      * <table summary="getBundle() locale to resource bundle mapping">
1281      * <tr><td>Locale("fr", "CH")</td><td>MyResources_fr_CH.class, parent MyResources_fr.properties, parent MyResources.class</td></tr>
1282      * <tr><td>Locale("fr", "FR")</td><td>MyResources_fr.properties, parent MyResources.class</td></tr>
1283      * <tr><td>Locale("de", "DE")</td><td>MyResources_en.properties, parent MyResources.class</td></tr>
1284      * <tr><td>Locale("en", "US")</td><td>MyResources_en.properties, parent MyResources.class</td></tr>
1285      * <tr><td>Locale("es", "ES")</td><td>MyResources_es_ES.class, parent MyResources.class</td></tr>
1286      * </table>
1287      *
1288      * <p>The file MyResources_fr_CH.properties is never used because it is
1289      * hidden by the MyResources_fr_CH.class. Likewise, MyResources.properties
1290      * is also hidden by MyResources.class.
1291      *
1292      * @apiNote If the caller module is a named module and the given
1293      * {@code loader} is the caller module's class loader, this method is
1294      * equivalent to {@code getBundle(baseName, locale)}; otherwise, it will not
1295      * find resource bundles from named modules.
1296      * Use {@link #getBundle(String, Locale, Module)} to load resource bundles
1297      * on behalf on a specific module instead.
1298      *
1299      * @param baseName the base name of the resource bundle, a fully qualified class name
1300      * @param locale the locale for which a resource bundle is desired
1301      * @param loader the class loader from which to load the resource bundle
1302      * @return a resource bundle for the given base name and locale
1303      * @exception java.lang.NullPointerException
1304      *        if <code>baseName</code>, <code>locale</code>, or <code>loader</code> is <code>null</code>
1305      * @exception MissingResourceException
1306      *        if no resource bundle for the specified base name can be found
1307      * @since 1.2
1308      */
1309     @CallerSensitive
1310     public static ResourceBundle getBundle(String baseName, Locale locale,
1311                                            ClassLoader loader)
1312     {
1313         if (loader == null) {
1314             throw new NullPointerException();
1315         }
1316         Class<?> caller = Reflection.getCallerClass();
1317         return getBundleImpl(baseName, locale, caller, loader, getDefaultControl(caller, baseName));
1318     }
1319 
1320     /**
1321      * Returns a resource bundle using the specified base name, target
1322      * locale, class loader and control. Unlike the {@linkplain
1323      * #getBundle(String, Locale, ClassLoader) <code>getBundle</code>
1324      * factory methods with no <code>control</code> argument}, the given
1325      * <code>control</code> specifies how to locate and instantiate resource
1326      * bundles. Conceptually, the bundle loading process with the given
1327      * <code>control</code> is performed in the following steps.
1328      *
1329      * <ol>
1330      * <li>This factory method looks up the resource bundle in the cache for
1331      * the specified <code>baseName</code>, <code>targetLocale</code> and
1332      * <code>loader</code>.  If the requested resource bundle instance is
1333      * found in the cache and the time-to-live periods of the instance and
1334      * all of its parent instances have not expired, the instance is returned
1335      * to the caller. Otherwise, this factory method proceeds with the
1336      * loading process below.</li>
1337      *
1338      * <li>The {@link ResourceBundle.Control#getFormats(String)
1339      * control.getFormats} method is called to get resource bundle formats
1340      * to produce bundle or resource names. The strings
1341      * <code>"java.class"</code> and <code>"java.properties"</code>
1342      * designate class-based and {@linkplain PropertyResourceBundle
1343      * property}-based resource bundles, respectively. Other strings
1344      * starting with <code>"java."</code> are reserved for future extensions
1345      * and must not be used for application-defined formats. Other strings
1346      * designate application-defined formats.</li>
1347      *
1348      * <li>The {@link ResourceBundle.Control#getCandidateLocales(String,
1349      * Locale) control.getCandidateLocales} method is called with the target
1350      * locale to get a list of <em>candidate <code>Locale</code>s</em> for
1351      * which resource bundles are searched.</li>
1352      *
1353      * <li>The {@link ResourceBundle.Control#newBundle(String, Locale,
1354      * String, ClassLoader, boolean) control.newBundle} method is called to
1355      * instantiate a <code>ResourceBundle</code> for the base bundle name, a
1356      * candidate locale, and a format. (Refer to the note on the cache
1357      * lookup below.) This step is iterated over all combinations of the
1358      * candidate locales and formats until the <code>newBundle</code> method
1359      * returns a <code>ResourceBundle</code> instance or the iteration has
1360      * used up all the combinations. For example, if the candidate locales
1361      * are <code>Locale("de", "DE")</code>, <code>Locale("de")</code> and
1362      * <code>Locale("")</code> and the formats are <code>"java.class"</code>
1363      * and <code>"java.properties"</code>, then the following is the
1364      * sequence of locale-format combinations to be used to call
1365      * <code>control.newBundle</code>.
1366      *
1367      * <table style="width: 50%; text-align: left; margin-left: 40px;"
1368      *  border="0" cellpadding="2" cellspacing="2" summary="locale-format combinations for newBundle">
1369      * <tbody>
1370      * <tr>
1371      * <td
1372      * style="vertical-align: top; text-align: left; font-weight: bold; width: 50%;"><code>Locale</code><br>
1373      * </td>
1374      * <td
1375      * style="vertical-align: top; text-align: left; font-weight: bold; width: 50%;"><code>format</code><br>
1376      * </td>
1377      * </tr>
1378      * <tr>
1379      * <td style="vertical-align: top; width: 50%;"><code>Locale("de", "DE")</code><br>
1380      * </td>
1381      * <td style="vertical-align: top; width: 50%;"><code>java.class</code><br>
1382      * </td>
1383      * </tr>
1384      * <tr>
1385      * <td style="vertical-align: top; width: 50%;"><code>Locale("de", "DE")</code></td>
1386      * <td style="vertical-align: top; width: 50%;"><code>java.properties</code><br>
1387      * </td>
1388      * </tr>
1389      * <tr>
1390      * <td style="vertical-align: top; width: 50%;"><code>Locale("de")</code></td>
1391      * <td style="vertical-align: top; width: 50%;"><code>java.class</code></td>
1392      * </tr>
1393      * <tr>
1394      * <td style="vertical-align: top; width: 50%;"><code>Locale("de")</code></td>
1395      * <td style="vertical-align: top; width: 50%;"><code>java.properties</code></td>
1396      * </tr>
1397      * <tr>
1398      * <td style="vertical-align: top; width: 50%;"><code>Locale("")</code><br>
1399      * </td>
1400      * <td style="vertical-align: top; width: 50%;"><code>java.class</code></td>
1401      * </tr>
1402      * <tr>
1403      * <td style="vertical-align: top; width: 50%;"><code>Locale("")</code></td>
1404      * <td style="vertical-align: top; width: 50%;"><code>java.properties</code></td>
1405      * </tr>
1406      * </tbody>
1407      * </table>
1408      * </li>
1409      *
1410      * <li>If the previous step has found no resource bundle, proceed to
1411      * Step 6. If a bundle has been found that is a base bundle (a bundle
1412      * for <code>Locale("")</code>), and the candidate locale list only contained
1413      * <code>Locale("")</code>, return the bundle to the caller. If a bundle
1414      * has been found that is a base bundle, but the candidate locale list
1415      * contained locales other than Locale(""), put the bundle on hold and
1416      * proceed to Step 6. If a bundle has been found that is not a base
1417      * bundle, proceed to Step 7.</li>
1418      *
1419      * <li>The {@link ResourceBundle.Control#getFallbackLocale(String,
1420      * Locale) control.getFallbackLocale} method is called to get a fallback
1421      * locale (alternative to the current target locale) to try further
1422      * finding a resource bundle. If the method returns a non-null locale,
1423      * it becomes the next target locale and the loading process starts over
1424      * from Step 3. Otherwise, if a base bundle was found and put on hold in
1425      * a previous Step 5, it is returned to the caller now. Otherwise, a
1426      * MissingResourceException is thrown.</li>
1427      *
1428      * <li>At this point, we have found a resource bundle that's not the
1429      * base bundle. If this bundle set its parent during its instantiation,
1430      * it is returned to the caller. Otherwise, its <a
1431      * href="./ResourceBundle.html#parent_chain">parent chain</a> is
1432      * instantiated based on the list of candidate locales from which it was
1433      * found. Finally, the bundle is returned to the caller.</li>
1434      * </ol>
1435      *
1436      * <p>During the resource bundle loading process above, this factory
1437      * method looks up the cache before calling the {@link
1438      * Control#newBundle(String, Locale, String, ClassLoader, boolean)
1439      * control.newBundle} method.  If the time-to-live period of the
1440      * resource bundle found in the cache has expired, the factory method
1441      * calls the {@link ResourceBundle.Control#needsReload(String, Locale,
1442      * String, ClassLoader, ResourceBundle, long) control.needsReload}
1443      * method to determine whether the resource bundle needs to be reloaded.
1444      * If reloading is required, the factory method calls
1445      * <code>control.newBundle</code> to reload the resource bundle.  If
1446      * <code>control.newBundle</code> returns <code>null</code>, the factory
1447      * method puts a dummy resource bundle in the cache as a mark of
1448      * nonexistent resource bundles in order to avoid lookup overhead for
1449      * subsequent requests. Such dummy resource bundles are under the same
1450      * expiration control as specified by <code>control</code>.
1451      *
1452      * <p>All resource bundles loaded are cached by default. Refer to
1453      * {@link Control#getTimeToLive(String,Locale)
1454      * control.getTimeToLive} for details.
1455      *
1456      * <p>The following is an example of the bundle loading process with the
1457      * default <code>ResourceBundle.Control</code> implementation.
1458      *
1459      * <p>Conditions:
1460      * <ul>
1461      * <li>Base bundle name: <code>foo.bar.Messages</code>
1462      * <li>Requested <code>Locale</code>: {@link Locale#ITALY}</li>
1463      * <li>Default <code>Locale</code>: {@link Locale#FRENCH}</li>
1464      * <li>Available resource bundles:
1465      * <code>foo/bar/Messages_fr.properties</code> and
1466      * <code>foo/bar/Messages.properties</code></li>
1467      * </ul>
1468      *
1469      * <p>First, <code>getBundle</code> tries loading a resource bundle in
1470      * the following sequence.
1471      *
1472      * <ul>
1473      * <li>class <code>foo.bar.Messages_it_IT</code>
1474      * <li>file <code>foo/bar/Messages_it_IT.properties</code>
1475      * <li>class <code>foo.bar.Messages_it</code></li>
1476      * <li>file <code>foo/bar/Messages_it.properties</code></li>
1477      * <li>class <code>foo.bar.Messages</code></li>
1478      * <li>file <code>foo/bar/Messages.properties</code></li>
1479      * </ul>
1480      *
1481      * <p>At this point, <code>getBundle</code> finds
1482      * <code>foo/bar/Messages.properties</code>, which is put on hold
1483      * because it's the base bundle.  <code>getBundle</code> calls {@link
1484      * Control#getFallbackLocale(String, Locale)
1485      * control.getFallbackLocale("foo.bar.Messages", Locale.ITALY)} which
1486      * returns <code>Locale.FRENCH</code>. Next, <code>getBundle</code>
1487      * tries loading a bundle in the following sequence.
1488      *
1489      * <ul>
1490      * <li>class <code>foo.bar.Messages_fr</code></li>
1491      * <li>file <code>foo/bar/Messages_fr.properties</code></li>
1492      * <li>class <code>foo.bar.Messages</code></li>
1493      * <li>file <code>foo/bar/Messages.properties</code></li>
1494      * </ul>
1495      *
1496      * <p><code>getBundle</code> finds
1497      * <code>foo/bar/Messages_fr.properties</code> and creates a
1498      * <code>ResourceBundle</code> instance. Then, <code>getBundle</code>
1499      * sets up its parent chain from the list of the candidate locales.  Only
1500      * <code>foo/bar/Messages.properties</code> is found in the list and
1501      * <code>getBundle</code> creates a <code>ResourceBundle</code> instance
1502      * that becomes the parent of the instance for
1503      * <code>foo/bar/Messages_fr.properties</code>.
1504      *
1505      * @param baseName
1506      *        the base name of the resource bundle, a fully qualified
1507      *        class name
1508      * @param targetLocale
1509      *        the locale for which a resource bundle is desired
1510      * @param loader
1511      *        the class loader from which to load the resource bundle
1512      * @param control
1513      *        the control which gives information for the resource
1514      *        bundle loading process
1515      * @return a resource bundle for the given base name and locale
1516      * @throws NullPointerException
1517      *         if <code>baseName</code>, <code>targetLocale</code>,
1518      *         <code>loader</code>, or <code>control</code> is
1519      *         <code>null</code>
1520      * @throws MissingResourceException
1521      *         if no resource bundle for the specified base name can be found
1522      * @throws IllegalArgumentException
1523      *         if the given <code>control</code> doesn't perform properly
1524      *         (e.g., <code>control.getCandidateLocales</code> returns null.)
1525      *         Note that validation of <code>control</code> is performed as
1526      *         needed.
1527      * @throws UnsupportedOperationException
1528      *         if this method is called in a named module
1529      * @since 1.6
1530      */
1531     @CallerSensitive
1532     public static ResourceBundle getBundle(String baseName, Locale targetLocale,
1533                                            ClassLoader loader, Control control) {
1534         if (loader == null || control == null) {
1535             throw new NullPointerException();
1536         }
1537         Class<?> caller = Reflection.getCallerClass();
1538         checkNamedModule(caller);
1539         return getBundleImpl(baseName, targetLocale, caller, loader, control);
1540     }
1541 
1542     private static Control getDefaultControl(Class<?> caller, String baseName) {
1543         if (providers != null && !caller.getModule().isNamed()) {
1544             for (ResourceBundleControlProvider provider : providers) {
1545                 Control control = provider.getControl(baseName);
1546                 if (control != null) {
1547                     return control;
1548                 }
1549             }
1550         }
1551         return Control.INSTANCE;
1552     }
1553 
1554     private static void checkNamedModule(Class<?> caller) {
1555         if (caller.getModule().isNamed()) {
1556             throw new UnsupportedOperationException(
1557                     "ResourceBundle.Control not supported in named modules");
1558         }
1559     }
1560 
1561     private static ResourceBundle getBundleImpl(String baseName,
1562                                                 Locale locale,
1563                                                 Class<?> caller,
1564                                                 Control control) {
1565         return getBundleImpl(baseName, locale, caller, getLoader(caller), control);
1566     }
1567 
1568     /**
1569      * This method will find resource bundles using the legacy mechanism
1570      * if the caller is unnamed module or the given class loader is
1571      * not the class loader of the caller module getting the resource
1572      * bundle, i.e. find the class that is visible to the class loader
1573      * and properties from unnamed module.
1574      *
1575      * The module-aware resource bundle lookup mechanism will load
1576      * the service providers using the service loader mechanism
1577      * as well as properties local in the caller module.
1578      */
1579     private static ResourceBundle getBundleImpl(String baseName,
1580                                                 Locale locale,
1581                                                 Class<?> caller,
1582                                                 ClassLoader loader,
1583                                                 Control control) {
1584         if (caller != null && caller.getModule().isNamed()) {
1585             Module module = caller.getModule();
1586             ClassLoader ml = getLoader(module);
1587             // get resource bundles for a named module only
1588             // if loader is the module's class loader
1589             if (loader == ml || (ml == null && loader == RBClassLoader.INSTANCE)) {
1590                 return getBundleImpl(baseName, locale, loader, module, control);
1591             }
1592         }
1593         // find resource bundles from unnamed module
1594         Module module = loader != null ? loader.getUnnamedModule()
1595                                        : ClassLoader.getSystemClassLoader().getUnnamedModule();
1596         return getBundleImpl(baseName, locale, loader, module, control);
1597     }
1598 
1599     private static ResourceBundle getBundleFromModule(Class<?> caller,
1600                                                       Module module,
1601                                                       String baseName,
1602                                                       Locale locale,
1603                                                       Control control) {
1604         Objects.requireNonNull(module);
1605         if (caller.getModule() != module) {
1606             SecurityManager sm = System.getSecurityManager();
1607             if (sm != null) {
1608                 sm.checkPermission(GET_CLASSLOADER_PERMISSION);
1609             }
1610         }
1611         return getBundleImpl(baseName, locale, getLoader(module), module, control);
1612     }
1613 
1614     private static ResourceBundle getBundleImpl(String baseName,
1615                                                 Locale locale,
1616                                                 ClassLoader loader,
1617                                                 Module module,
1618                                                 Control control) {
1619         if (locale == null || control == null) {
1620             throw new NullPointerException();
1621         }
1622 
1623         // We create a CacheKey here for use by this call. The base name
1624         // loader, and module will never change during the bundle loading
1625         // process. We have to make sure that the locale is set before
1626         // using it as a cache key.
1627         CacheKey cacheKey = new CacheKey(baseName, locale, loader, module);
1628         ResourceBundle bundle = null;
1629 
1630         // Quick lookup of the cache.
1631         BundleReference bundleRef = cacheList.get(cacheKey);
1632         if (bundleRef != null) {
1633             bundle = bundleRef.get();
1634             bundleRef = null;
1635         }
1636 
1637         // If this bundle and all of its parents are valid (not expired),
1638         // then return this bundle. If any of the bundles is expired, we
1639         // don't call control.needsReload here but instead drop into the
1640         // complete loading process below.
1641         if (isValidBundle(bundle) && hasValidParentChain(bundle)) {
1642             return bundle;
1643         }
1644 
1645         // No valid bundle was found in the cache, so we need to load the
1646         // resource bundle and its parents.
1647 
1648         boolean isKnownControl = (control == Control.INSTANCE) ||
1649                                    (control instanceof SingleFormatControl);
1650         List<String> formats = control.getFormats(baseName);
1651         if (!isKnownControl && !checkList(formats)) {
1652             throw new IllegalArgumentException("Invalid Control: getFormats");
1653         }
1654 
1655         ResourceBundle baseBundle = null;
1656         for (Locale targetLocale = locale;
1657              targetLocale != null;
1658              targetLocale = control.getFallbackLocale(baseName, targetLocale)) {
1659             List<Locale> candidateLocales = control.getCandidateLocales(baseName, targetLocale);
1660             if (!isKnownControl && !checkList(candidateLocales)) {
1661                 throw new IllegalArgumentException("Invalid Control: getCandidateLocales");
1662             }
1663 
1664             bundle = findBundle(cacheKey, module, candidateLocales, formats, 0, control, baseBundle);
1665 
1666             // If the loaded bundle is the base bundle and exactly for the
1667             // requested locale or the only candidate locale, then take the
1668             // bundle as the resulting one. If the loaded bundle is the base
1669             // bundle, it's put on hold until we finish processing all
1670             // fallback locales.
1671             if (isValidBundle(bundle)) {
1672                 boolean isBaseBundle = Locale.ROOT.equals(bundle.locale);
1673                 if (!isBaseBundle || bundle.locale.equals(locale)
1674                     || (candidateLocales.size() == 1
1675                         && bundle.locale.equals(candidateLocales.get(0)))) {
1676                     break;
1677                 }
1678 
1679                 // If the base bundle has been loaded, keep the reference in
1680                 // baseBundle so that we can avoid any redundant loading in case
1681                 // the control specify not to cache bundles.
1682                 if (isBaseBundle && baseBundle == null) {
1683                     baseBundle = bundle;
1684                 }
1685             }
1686         }
1687 
1688         if (bundle == null) {
1689             if (baseBundle == null) {
1690                 throwMissingResourceException(baseName, locale, cacheKey.getCause());
1691             }
1692             bundle = baseBundle;
1693         }
1694 
1695         return bundle;
1696     }
1697 
1698     /**
1699      * Checks if the given <code>List</code> is not null, not empty,
1700      * not having null in its elements.
1701      */
1702     private static boolean checkList(List<?> a) {
1703         boolean valid = (a != null && !a.isEmpty());
1704         if (valid) {
1705             int size = a.size();
1706             for (int i = 0; valid && i < size; i++) {
1707                 valid = (a.get(i) != null);
1708             }
1709         }
1710         return valid;
1711     }
1712 
1713     private static ResourceBundle findBundle(CacheKey cacheKey,
1714                                              Module module,
1715                                              List<Locale> candidateLocales,
1716                                              List<String> formats,
1717                                              int index,
1718                                              Control control,
1719                                              ResourceBundle baseBundle) {
1720         Locale targetLocale = candidateLocales.get(index);
1721         ResourceBundle parent = null;
1722         if (index != candidateLocales.size() - 1) {
1723             parent = findBundle(cacheKey, module, candidateLocales, formats, index + 1,
1724                                 control, baseBundle);
1725         } else if (baseBundle != null && Locale.ROOT.equals(targetLocale)) {
1726             return baseBundle;
1727         }
1728 
1729         // Before we do the real loading work, see whether we need to
1730         // do some housekeeping: If references to class loaders or
1731         // resource bundles have been nulled out, remove all related
1732         // information from the cache.
1733         Object ref;
1734         while ((ref = referenceQueue.poll()) != null) {
1735             cacheList.remove(((CacheKeyReference)ref).getCacheKey());
1736         }
1737 
1738         // flag indicating the resource bundle has expired in the cache
1739         boolean expiredBundle = false;
1740 
1741         // First, look up the cache to see if it's in the cache, without
1742         // attempting to load bundle.
1743         cacheKey.setLocale(targetLocale);
1744         ResourceBundle bundle = findBundleInCache(cacheKey, control);
1745         if (isValidBundle(bundle)) {
1746             expiredBundle = bundle.expired;
1747             if (!expiredBundle) {
1748                 // If its parent is the one asked for by the candidate
1749                 // locales (the runtime lookup path), we can take the cached
1750                 // one. (If it's not identical, then we'd have to check the
1751                 // parent's parents to be consistent with what's been
1752                 // requested.)
1753                 if (bundle.parent == parent) {
1754                     return bundle;
1755                 }
1756                 // Otherwise, remove the cached one since we can't keep
1757                 // the same bundles having different parents.
1758                 BundleReference bundleRef = cacheList.get(cacheKey);
1759                 if (bundleRef != null && bundleRef.get() == bundle) {
1760                     cacheList.remove(cacheKey, bundleRef);
1761                 }
1762             }
1763         }
1764 
1765         if (bundle != NONEXISTENT_BUNDLE) {
1766             CacheKey constKey = (CacheKey) cacheKey.clone();
1767 
1768             try {
1769                 if (module.isNamed()) {
1770                     bundle = loadBundle(cacheKey, formats, control, module);
1771                 } else {
1772                     bundle = loadBundle(cacheKey, formats, control, expiredBundle);
1773                 }
1774                 if (bundle != null) {
1775                     if (bundle.parent == null) {
1776                         bundle.setParent(parent);
1777                     }
1778                     bundle.locale = targetLocale;
1779                     bundle = putBundleInCache(cacheKey, bundle, control);
1780                     return bundle;
1781                 }
1782 
1783                 // Put NONEXISTENT_BUNDLE in the cache as a mark that there's no bundle
1784                 // instance for the locale.
1785                 putBundleInCache(cacheKey, NONEXISTENT_BUNDLE, control);
1786             } finally {
1787                 if (constKey.getCause() instanceof InterruptedException) {
1788                     Thread.currentThread().interrupt();
1789                 }
1790             }
1791         }
1792         return parent;
1793     }
1794 
1795     private static final String UNKNOWN_FORMAT = "";
1796 
1797     /*
1798      * Loads a ResourceBundle in named modules
1799      */
1800     private static ResourceBundle loadBundle(CacheKey cacheKey,
1801                                              List<String> formats,
1802                                              Control control,
1803                                              Module module) {
1804         String baseName = cacheKey.getName();
1805         Locale targetLocale = cacheKey.getLocale();
1806 
1807         ResourceBundle bundle = null;
1808         if (cacheKey.hasProviders()) {
1809             bundle = loadBundleFromProviders(baseName, targetLocale,
1810                                              cacheKey.getProviders(), cacheKey);
1811             if (bundle != null) {
1812                 cacheKey.setFormat(UNKNOWN_FORMAT);
1813             }
1814         }
1815         // If none of providers returned a bundle and the caller has no provider,
1816         // look up module-local bundles.
1817         if (bundle == null && !cacheKey.callerHasProvider()) {
1818             String bundleName = control.toBundleName(baseName, targetLocale);
1819             for (String format : formats) {
1820                 try {
1821                     switch (format) {
1822                     case "java.class":
1823                         PrivilegedAction<ResourceBundle> pa = ()
1824                                 -> ResourceBundleProviderSupport
1825                                     .loadResourceBundle(module, bundleName);
1826                         bundle = AccessController.doPrivileged(pa, null, GET_CLASSLOADER_PERMISSION);
1827                         break;
1828                     case "java.properties":
1829                         bundle = ResourceBundleProviderSupport.loadPropertyResourceBundle(module, bundleName);
1830                         break;
1831                     default:
1832                         throw new InternalError("unexpected format: " + format);
1833                     }
1834 
1835                     if (bundle != null) {
1836                         cacheKey.setFormat(format);
1837                         break;
1838                     }
1839                 } catch (Exception e) {
1840                     cacheKey.setCause(e);
1841                 }
1842             }
1843         }
1844         return bundle;
1845     }
1846 
1847     private static ServiceLoader<ResourceBundleProvider> getServiceLoader(Module module,
1848                                                                           String baseName) {
1849         if (!module.isNamed()) {
1850             return null;
1851         }
1852         PrivilegedAction<ClassLoader> pa = module::getClassLoader;
1853         ClassLoader loader = AccessController.doPrivileged(pa);
1854         return getServiceLoader(module, loader, baseName);
1855     }
1856 
1857         /**
1858          * Returns a ServiceLoader that will find providers that are bound to
1859          * a given module that may be named or unnamed.
1860          */
1861     private static ServiceLoader<ResourceBundleProvider> getServiceLoader(Module module,
1862                                                                           ClassLoader loader,
1863                                                                           String baseName)
1864     {
1865         // Look up <baseName> + "Provider"
1866         String providerName = baseName + "Provider";
1867         // Use the class loader of the getBundle caller so that the caller's
1868         // visibility of the provider type is checked.
1869         Class<ResourceBundleProvider> service = AccessController.doPrivileged(
1870             new PrivilegedAction<>() {
1871                 @Override
1872                 public Class<ResourceBundleProvider> run() {
1873                     try {
1874                         Class<?> c = Class.forName(providerName, false, loader);
1875                         if (ResourceBundleProvider.class.isAssignableFrom(c)) {
1876                             @SuppressWarnings("unchecked")
1877                             Class<ResourceBundleProvider> s = (Class<ResourceBundleProvider>) c;
1878                             return s;
1879                         }
1880                     } catch (ClassNotFoundException e) {}
1881                     return null;
1882                 }
1883             });
1884 
1885         if (service != null && Reflection.verifyModuleAccess(module, service)) {
1886             try {
1887                 return ServiceLoader.load(service, loader, module);
1888             } catch (ServiceConfigurationError e) {
1889                 // "uses" not declared: load bundle local in the module
1890                 return null;
1891             }
1892         }
1893         return null;
1894     }
1895 
1896     /**
1897      * Loads ResourceBundle from service providers.
1898      */
1899     private static ResourceBundle loadBundleFromProviders(String baseName,
1900                                                           Locale locale,
1901                                                           ServiceLoader<ResourceBundleProvider> providers,
1902                                                           CacheKey cacheKey)
1903     {
1904         if (providers == null) return null;
1905 
1906         return AccessController.doPrivileged(
1907                 new PrivilegedAction<>() {
1908                     public ResourceBundle run() {
1909                         for (Iterator<ResourceBundleProvider> itr = providers.iterator(); itr.hasNext(); ) {
1910                             try {
1911                                 ResourceBundleProvider provider = itr.next();
1912                                 if (cacheKey != null && cacheKey.callerHasProvider == null
1913                                         && cacheKey.getModule() == provider.getClass().getModule()) {
1914                                     cacheKey.callerHasProvider = Boolean.TRUE;
1915                                 }
1916                                 ResourceBundle bundle = provider.getBundle(baseName, locale);
1917                                 if (bundle != null) {
1918                                     return bundle;
1919                                 }
1920                             } catch (ServiceConfigurationError | SecurityException e) {
1921                                 if (cacheKey != null) {
1922                                     cacheKey.setCause(e);
1923                                 }
1924                             }
1925                         }
1926                         if (cacheKey != null && cacheKey.callerHasProvider == null) {
1927                             cacheKey.callerHasProvider = Boolean.FALSE;
1928                         }
1929                         return null;
1930                     }
1931                 });
1932 
1933     }
1934 
1935     /*
1936      * Legacy mechanism to load resource bundles
1937      */
1938     private static ResourceBundle loadBundle(CacheKey cacheKey,
1939                                              List<String> formats,
1940                                              Control control,
1941                                              boolean reload) {
1942 
1943         // Here we actually load the bundle in the order of formats
1944         // specified by the getFormats() value.
1945         Locale targetLocale = cacheKey.getLocale();
1946 
1947         ResourceBundle bundle = null;
1948         for (String format : formats) {
1949             try {
1950                 // ResourceBundle.Control.newBundle may be overridden
1951                 bundle = control.newBundle(cacheKey.getName(), targetLocale, format,
1952                                            cacheKey.getLoader(), reload);
1953             } catch (LinkageError | Exception error) {
1954                 // We need to handle the LinkageError case due to
1955                 // inconsistent case-sensitivity in ClassLoader.
1956                 // See 6572242 for details.
1957                 cacheKey.setCause(error);
1958             }
1959             if (bundle != null) {
1960                 // Set the format in the cache key so that it can be
1961                 // used when calling needsReload later.
1962                 cacheKey.setFormat(format);
1963                 bundle.name = cacheKey.getName();
1964                 bundle.locale = targetLocale;
1965                 // Bundle provider might reuse instances. So we should make
1966                 // sure to clear the expired flag here.
1967                 bundle.expired = false;
1968                 break;
1969             }
1970         }
1971 
1972         return bundle;
1973     }
1974 
1975     private static boolean isValidBundle(ResourceBundle bundle) {
1976         return bundle != null && bundle != NONEXISTENT_BUNDLE;
1977     }
1978 
1979     /**
1980      * Determines whether any of resource bundles in the parent chain,
1981      * including the leaf, have expired.
1982      */
1983     private static boolean hasValidParentChain(ResourceBundle bundle) {
1984         long now = System.currentTimeMillis();
1985         while (bundle != null) {
1986             if (bundle.expired) {
1987                 return false;
1988             }
1989             CacheKey key = bundle.cacheKey;
1990             if (key != null) {
1991                 long expirationTime = key.expirationTime;
1992                 if (expirationTime >= 0 && expirationTime <= now) {
1993                     return false;
1994                 }
1995             }
1996             bundle = bundle.parent;
1997         }
1998         return true;
1999     }
2000 
2001     /**
2002      * Throw a MissingResourceException with proper message
2003      */
2004     private static void throwMissingResourceException(String baseName,
2005                                                       Locale locale,
2006                                                       Throwable cause) {
2007         // If the cause is a MissingResourceException, avoid creating
2008         // a long chain. (6355009)
2009         if (cause instanceof MissingResourceException) {
2010             cause = null;
2011         }
2012         throw new MissingResourceException("Can't find bundle for base name "
2013                                            + baseName + ", locale " + locale,
2014                                            baseName + "_" + locale, // className
2015                                            "",                      // key
2016                                            cause);
2017     }
2018 
2019     /**
2020      * Finds a bundle in the cache. Any expired bundles are marked as
2021      * `expired' and removed from the cache upon return.
2022      *
2023      * @param cacheKey the key to look up the cache
2024      * @param control the Control to be used for the expiration control
2025      * @return the cached bundle, or null if the bundle is not found in the
2026      * cache or its parent has expired. <code>bundle.expire</code> is true
2027      * upon return if the bundle in the cache has expired.
2028      */
2029     private static ResourceBundle findBundleInCache(CacheKey cacheKey,
2030                                                     Control control) {
2031         BundleReference bundleRef = cacheList.get(cacheKey);
2032         if (bundleRef == null) {
2033             return null;
2034         }
2035         ResourceBundle bundle = bundleRef.get();
2036         if (bundle == null) {
2037             return null;
2038         }
2039         ResourceBundle p = bundle.parent;
2040         assert p != NONEXISTENT_BUNDLE;
2041         // If the parent has expired, then this one must also expire. We
2042         // check only the immediate parent because the actual loading is
2043         // done from the root (base) to leaf (child) and the purpose of
2044         // checking is to propagate expiration towards the leaf. For
2045         // example, if the requested locale is ja_JP_JP and there are
2046         // bundles for all of the candidates in the cache, we have a list,
2047         //
2048         // base <- ja <- ja_JP <- ja_JP_JP
2049         //
2050         // If ja has expired, then it will reload ja and the list becomes a
2051         // tree.
2052         //
2053         // base <- ja (new)
2054         //  "   <- ja (expired) <- ja_JP <- ja_JP_JP
2055         //
2056         // When looking up ja_JP in the cache, it finds ja_JP in the cache
2057         // which references to the expired ja. Then, ja_JP is marked as
2058         // expired and removed from the cache. This will be propagated to
2059         // ja_JP_JP.
2060         //
2061         // Now, it's possible, for example, that while loading new ja_JP,
2062         // someone else has started loading the same bundle and finds the
2063         // base bundle has expired. Then, what we get from the first
2064         // getBundle call includes the expired base bundle. However, if
2065         // someone else didn't start its loading, we wouldn't know if the
2066         // base bundle has expired at the end of the loading process. The
2067         // expiration control doesn't guarantee that the returned bundle and
2068         // its parents haven't expired.
2069         //
2070         // We could check the entire parent chain to see if there's any in
2071         // the chain that has expired. But this process may never end. An
2072         // extreme case would be that getTimeToLive returns 0 and
2073         // needsReload always returns true.
2074         if (p != null && p.expired) {
2075             assert bundle != NONEXISTENT_BUNDLE;
2076             bundle.expired = true;
2077             bundle.cacheKey = null;
2078             cacheList.remove(cacheKey, bundleRef);
2079             bundle = null;
2080         } else {
2081             CacheKey key = bundleRef.getCacheKey();
2082             long expirationTime = key.expirationTime;
2083             if (!bundle.expired && expirationTime >= 0 &&
2084                 expirationTime <= System.currentTimeMillis()) {
2085                 // its TTL period has expired.
2086                 if (bundle != NONEXISTENT_BUNDLE) {
2087                     // Synchronize here to call needsReload to avoid
2088                     // redundant concurrent calls for the same bundle.
2089                     synchronized (bundle) {
2090                         expirationTime = key.expirationTime;
2091                         if (!bundle.expired && expirationTime >= 0 &&
2092                             expirationTime <= System.currentTimeMillis()) {
2093                             try {
2094                                 bundle.expired = control.needsReload(key.getName(),
2095                                                                      key.getLocale(),
2096                                                                      key.getFormat(),
2097                                                                      key.getLoader(),
2098                                                                      bundle,
2099                                                                      key.loadTime);
2100                             } catch (Exception e) {
2101                                 cacheKey.setCause(e);
2102                             }
2103                             if (bundle.expired) {
2104                                 // If the bundle needs to be reloaded, then
2105                                 // remove the bundle from the cache, but
2106                                 // return the bundle with the expired flag
2107                                 // on.
2108                                 bundle.cacheKey = null;
2109                                 cacheList.remove(cacheKey, bundleRef);
2110                             } else {
2111                                 // Update the expiration control info. and reuse
2112                                 // the same bundle instance
2113                                 setExpirationTime(key, control);
2114                             }
2115                         }
2116                     }
2117                 } else {
2118                     // We just remove NONEXISTENT_BUNDLE from the cache.
2119                     cacheList.remove(cacheKey, bundleRef);
2120                     bundle = null;
2121                 }
2122             }
2123         }
2124         return bundle;
2125     }
2126 
2127     /**
2128      * Put a new bundle in the cache.
2129      *
2130      * @param cacheKey the key for the resource bundle
2131      * @param bundle the resource bundle to be put in the cache
2132      * @return the ResourceBundle for the cacheKey; if someone has put
2133      * the bundle before this call, the one found in the cache is
2134      * returned.
2135      */
2136     private static ResourceBundle putBundleInCache(CacheKey cacheKey,
2137                                                    ResourceBundle bundle,
2138                                                    Control control) {
2139         setExpirationTime(cacheKey, control);
2140         if (cacheKey.expirationTime != Control.TTL_DONT_CACHE) {
2141             CacheKey key = (CacheKey) cacheKey.clone();
2142             BundleReference bundleRef = new BundleReference(bundle, referenceQueue, key);
2143             bundle.cacheKey = key;
2144 
2145             // Put the bundle in the cache if it's not been in the cache.
2146             BundleReference result = cacheList.putIfAbsent(key, bundleRef);
2147 
2148             // If someone else has put the same bundle in the cache before
2149             // us and it has not expired, we should use the one in the cache.
2150             if (result != null) {
2151                 ResourceBundle rb = result.get();
2152                 if (rb != null && !rb.expired) {
2153                     // Clear the back link to the cache key
2154                     bundle.cacheKey = null;
2155                     bundle = rb;
2156                     // Clear the reference in the BundleReference so that
2157                     // it won't be enqueued.
2158                     bundleRef.clear();
2159                 } else {
2160                     // Replace the invalid (garbage collected or expired)
2161                     // instance with the valid one.
2162                     cacheList.put(key, bundleRef);
2163                 }
2164             }
2165         }
2166         return bundle;
2167     }
2168 
2169     private static void setExpirationTime(CacheKey cacheKey, Control control) {
2170         long ttl = control.getTimeToLive(cacheKey.getName(),
2171                                          cacheKey.getLocale());
2172         if (ttl >= 0) {
2173             // If any expiration time is specified, set the time to be
2174             // expired in the cache.
2175             long now = System.currentTimeMillis();
2176             cacheKey.loadTime = now;
2177             cacheKey.expirationTime = now + ttl;
2178         } else if (ttl >= Control.TTL_NO_EXPIRATION_CONTROL) {
2179             cacheKey.expirationTime = ttl;
2180         } else {
2181             throw new IllegalArgumentException("Invalid Control: TTL=" + ttl);
2182         }
2183     }
2184 
2185     /**
2186      * Removes all resource bundles from the cache that have been loaded
2187      * by the caller's module using the caller's class loader.
2188      *
2189      * @since 1.6
2190      * @see ResourceBundle.Control#getTimeToLive(String,Locale)
2191      */
2192     @CallerSensitive
2193     public static final void clearCache() {
2194         Class<?> caller = Reflection.getCallerClass();
2195         clearCache(getLoader(caller), caller.getModule());
2196     }
2197 
2198     /**
2199      * Removes all resource bundles from the cache that have been loaded
2200      * by the caller's module using the given class loader.
2201      *
2202      * @param loader the class loader
2203      * @exception NullPointerException if <code>loader</code> is null
2204      * @since 1.6
2205      * @see ResourceBundle.Control#getTimeToLive(String,Locale)
2206      */
2207     @CallerSensitive
2208     public static final void clearCache(ClassLoader loader) {
2209         Objects.requireNonNull(loader);
2210         clearCache(loader, Reflection.getCallerClass().getModule());
2211     }
2212 
2213     /**
2214      * Removes all resource bundles from the cache that have been loaded by the
2215      * given {@code module}.
2216      *
2217      * @param module the module
2218      * @throws NullPointerException
2219      *         if {@code module} is {@code null}
2220      * @throws SecurityException
2221      *         if the caller doesn't have the permission to
2222      *         {@linkplain Module#getClassLoader() get the class loader}
2223      *         of the given {@code module}
2224      * @since 9
2225      * @see ResourceBundle.Control#getTimeToLive(String,Locale)
2226      */
2227     public static final void clearCache(Module module) {
2228         clearCache(module.getClassLoader(), module);
2229     }
2230 
2231     private static void clearCache(ClassLoader loader, Module module) {
2232         Set<CacheKey> set = cacheList.keySet();
2233         set.stream().filter((key) -> (key.getLoader() == loader && key.getModule() == module))
2234                 .forEach(set::remove);
2235     }
2236 
2237     /**
2238      * Gets an object for the given key from this resource bundle.
2239      * Returns null if this resource bundle does not contain an
2240      * object for the given key.
2241      *
2242      * @param key the key for the desired object
2243      * @exception NullPointerException if <code>key</code> is <code>null</code>
2244      * @return the object for the given key, or null
2245      */
2246     protected abstract Object handleGetObject(String key);
2247 
2248     /**
2249      * Returns an enumeration of the keys.
2250      *
2251      * @return an <code>Enumeration</code> of the keys contained in
2252      *         this <code>ResourceBundle</code> and its parent bundles.
2253      */
2254     public abstract Enumeration<String> getKeys();
2255 
2256     /**
2257      * Determines whether the given <code>key</code> is contained in
2258      * this <code>ResourceBundle</code> or its parent bundles.
2259      *
2260      * @param key
2261      *        the resource <code>key</code>
2262      * @return <code>true</code> if the given <code>key</code> is
2263      *        contained in this <code>ResourceBundle</code> or its
2264      *        parent bundles; <code>false</code> otherwise.
2265      * @exception NullPointerException
2266      *         if <code>key</code> is <code>null</code>
2267      * @since 1.6
2268      */
2269     public boolean containsKey(String key) {
2270         if (key == null) {
2271             throw new NullPointerException();
2272         }
2273         for (ResourceBundle rb = this; rb != null; rb = rb.parent) {
2274             if (rb.handleKeySet().contains(key)) {
2275                 return true;
2276             }
2277         }
2278         return false;
2279     }
2280 
2281     /**
2282      * Returns a <code>Set</code> of all keys contained in this
2283      * <code>ResourceBundle</code> and its parent bundles.
2284      *
2285      * @return a <code>Set</code> of all keys contained in this
2286      *         <code>ResourceBundle</code> and its parent bundles.
2287      * @since 1.6
2288      */
2289     public Set<String> keySet() {
2290         Set<String> keys = new HashSet<>();
2291         for (ResourceBundle rb = this; rb != null; rb = rb.parent) {
2292             keys.addAll(rb.handleKeySet());
2293         }
2294         return keys;
2295     }
2296 
2297     /**
2298      * Returns a <code>Set</code> of the keys contained <em>only</em>
2299      * in this <code>ResourceBundle</code>.
2300      *
2301      * <p>The default implementation returns a <code>Set</code> of the
2302      * keys returned by the {@link #getKeys() getKeys} method except
2303      * for the ones for which the {@link #handleGetObject(String)
2304      * handleGetObject} method returns <code>null</code>. Once the
2305      * <code>Set</code> has been created, the value is kept in this
2306      * <code>ResourceBundle</code> in order to avoid producing the
2307      * same <code>Set</code> in subsequent calls. Subclasses can
2308      * override this method for faster handling.
2309      *
2310      * @return a <code>Set</code> of the keys contained only in this
2311      *        <code>ResourceBundle</code>
2312      * @since 1.6
2313      */
2314     protected Set<String> handleKeySet() {
2315         if (keySet == null) {
2316             synchronized (this) {
2317                 if (keySet == null) {
2318                     Set<String> keys = new HashSet<>();
2319                     Enumeration<String> enumKeys = getKeys();
2320                     while (enumKeys.hasMoreElements()) {
2321                         String key = enumKeys.nextElement();
2322                         if (handleGetObject(key) != null) {
2323                             keys.add(key);
2324                         }
2325                     }
2326                     keySet = keys;
2327                 }
2328             }
2329         }
2330         return keySet;
2331     }
2332 
2333 
2334 
2335     /**
2336      * <code>ResourceBundle.Control</code> defines a set of callback methods
2337      * that are invoked by the {@link ResourceBundle#getBundle(String,
2338      * Locale, ClassLoader, Control) ResourceBundle.getBundle} factory
2339      * methods during the bundle loading process. In other words, a
2340      * <code>ResourceBundle.Control</code> collaborates with the factory
2341      * methods for loading resource bundles. The default implementation of
2342      * the callback methods provides the information necessary for the
2343      * factory methods to perform the <a
2344      * href="./ResourceBundle.html#default_behavior">default behavior</a>.
2345      * <a href="#note">Note that this class is not supported in named modules.</a>
2346      *
2347      * <p>In addition to the callback methods, the {@link
2348      * #toBundleName(String, Locale) toBundleName} and {@link
2349      * #toResourceName(String, String) toResourceName} methods are defined
2350      * primarily for convenience in implementing the callback
2351      * methods. However, the <code>toBundleName</code> method could be
2352      * overridden to provide different conventions in the organization and
2353      * packaging of localized resources.  The <code>toResourceName</code>
2354      * method is <code>final</code> to avoid use of wrong resource and class
2355      * name separators.
2356      *
2357      * <p>Two factory methods, {@link #getControl(List)} and {@link
2358      * #getNoFallbackControl(List)}, provide
2359      * <code>ResourceBundle.Control</code> instances that implement common
2360      * variations of the default bundle loading process.
2361      *
2362      * <p>The formats returned by the {@link Control#getFormats(String)
2363      * getFormats} method and candidate locales returned by the {@link
2364      * ResourceBundle.Control#getCandidateLocales(String, Locale)
2365      * getCandidateLocales} method must be consistent in all
2366      * <code>ResourceBundle.getBundle</code> invocations for the same base
2367      * bundle. Otherwise, the <code>ResourceBundle.getBundle</code> methods
2368      * may return unintended bundles. For example, if only
2369      * <code>"java.class"</code> is returned by the <code>getFormats</code>
2370      * method for the first call to <code>ResourceBundle.getBundle</code>
2371      * and only <code>"java.properties"</code> for the second call, then the
2372      * second call will return the class-based one that has been cached
2373      * during the first call.
2374      *
2375      * <p>A <code>ResourceBundle.Control</code> instance must be thread-safe
2376      * if it's simultaneously used by multiple threads.
2377      * <code>ResourceBundle.getBundle</code> does not synchronize to call
2378      * the <code>ResourceBundle.Control</code> methods. The default
2379      * implementations of the methods are thread-safe.
2380      *
2381      * <p>Applications can specify <code>ResourceBundle.Control</code>
2382      * instances returned by the <code>getControl</code> factory methods or
2383      * created from a subclass of <code>ResourceBundle.Control</code> to
2384      * customize the bundle loading process. The following are examples of
2385      * changing the default bundle loading process.
2386      *
2387      * <p><b>Example 1</b>
2388      *
2389      * <p>The following code lets <code>ResourceBundle.getBundle</code> look
2390      * up only properties-based resources.
2391      *
2392      * <pre>
2393      * import java.util.*;
2394      * import static java.util.ResourceBundle.Control.*;
2395      * ...
2396      * ResourceBundle bundle =
2397      *   ResourceBundle.getBundle("MyResources", new Locale("fr", "CH"),
2398      *                            ResourceBundle.Control.getControl(FORMAT_PROPERTIES));
2399      * </pre>
2400      *
2401      * Given the resource bundles in the <a
2402      * href="./ResourceBundle.html#default_behavior_example">example</a> in
2403      * the <code>ResourceBundle.getBundle</code> description, this
2404      * <code>ResourceBundle.getBundle</code> call loads
2405      * <code>MyResources_fr_CH.properties</code> whose parent is
2406      * <code>MyResources_fr.properties</code> whose parent is
2407      * <code>MyResources.properties</code>. (<code>MyResources_fr_CH.properties</code>
2408      * is not hidden, but <code>MyResources_fr_CH.class</code> is.)
2409      *
2410      * <p><b>Example 2</b>
2411      *
2412      * <p>The following is an example of loading XML-based bundles
2413      * using {@link Properties#loadFromXML(java.io.InputStream)
2414      * Properties.loadFromXML}.
2415      *
2416      * <pre>
2417      * ResourceBundle rb = ResourceBundle.getBundle("Messages",
2418      *     new ResourceBundle.Control() {
2419      *         public List&lt;String&gt; getFormats(String baseName) {
2420      *             if (baseName == null)
2421      *                 throw new NullPointerException();
2422      *             return Arrays.asList("xml");
2423      *         }
2424      *         public ResourceBundle newBundle(String baseName,
2425      *                                         Locale locale,
2426      *                                         String format,
2427      *                                         ClassLoader loader,
2428      *                                         boolean reload)
2429      *                          throws IllegalAccessException,
2430      *                                 InstantiationException,
2431      *                                 IOException {
2432      *             if (baseName == null || locale == null
2433      *                   || format == null || loader == null)
2434      *                 throw new NullPointerException();
2435      *             ResourceBundle bundle = null;
2436      *             if (format.equals("xml")) {
2437      *                 String bundleName = toBundleName(baseName, locale);
2438      *                 String resourceName = toResourceName(bundleName, format);
2439      *                 InputStream stream = null;
2440      *                 if (reload) {
2441      *                     URL url = loader.getResource(resourceName);
2442      *                     if (url != null) {
2443      *                         URLConnection connection = url.openConnection();
2444      *                         if (connection != null) {
2445      *                             // Disable caches to get fresh data for
2446      *                             // reloading.
2447      *                             connection.setUseCaches(false);
2448      *                             stream = connection.getInputStream();
2449      *                         }
2450      *                     }
2451      *                 } else {
2452      *                     stream = loader.getResourceAsStream(resourceName);
2453      *                 }
2454      *                 if (stream != null) {
2455      *                     BufferedInputStream bis = new BufferedInputStream(stream);
2456      *                     bundle = new XMLResourceBundle(bis);
2457      *                     bis.close();
2458      *                 }
2459      *             }
2460      *             return bundle;
2461      *         }
2462      *     });
2463      *
2464      * ...
2465      *
2466      * private static class XMLResourceBundle extends ResourceBundle {
2467      *     private Properties props;
2468      *     XMLResourceBundle(InputStream stream) throws IOException {
2469      *         props = new Properties();
2470      *         props.loadFromXML(stream);
2471      *     }
2472      *     protected Object handleGetObject(String key) {
2473      *         return props.getProperty(key);
2474      *     }
2475      *     public Enumeration&lt;String&gt; getKeys() {
2476      *         ...
2477      *     }
2478      * }
2479      * </pre>
2480      *
2481      * @apiNote <a name="note">{@code ResourceBundle.Control} is not supported
2482      * in named modules.</a> If the {@code ResourceBundle.getBundle} method with
2483      * a {@code ResourceBundle.Control} is called in a named module, the method
2484      * will throw an {@link UnsupportedOperationException}. Any service providers
2485      * of {@link ResourceBundleControlProvider} are ignored in named modules.
2486      *
2487      * @since 1.6
2488      * @see java.util.spi.ResourceBundleProvider
2489      */
2490     public static class Control {
2491         /**
2492          * The default format <code>List</code>, which contains the strings
2493          * <code>"java.class"</code> and <code>"java.properties"</code>, in
2494          * this order. This <code>List</code> is {@linkplain
2495          * Collections#unmodifiableList(List) unmodifiable}.
2496          *
2497          * @see #getFormats(String)
2498          */
2499         public static final List<String> FORMAT_DEFAULT
2500             = Collections.unmodifiableList(Arrays.asList("java.class",
2501                                                          "java.properties"));
2502 
2503         /**
2504          * The class-only format <code>List</code> containing
2505          * <code>"java.class"</code>. This <code>List</code> is {@linkplain
2506          * Collections#unmodifiableList(List) unmodifiable}.
2507          *
2508          * @see #getFormats(String)
2509          */
2510         public static final List<String> FORMAT_CLASS
2511             = Collections.unmodifiableList(Arrays.asList("java.class"));
2512 
2513         /**
2514          * The properties-only format <code>List</code> containing
2515          * <code>"java.properties"</code>. This <code>List</code> is
2516          * {@linkplain Collections#unmodifiableList(List) unmodifiable}.
2517          *
2518          * @see #getFormats(String)
2519          */
2520         public static final List<String> FORMAT_PROPERTIES
2521             = Collections.unmodifiableList(Arrays.asList("java.properties"));
2522 
2523         /**
2524          * The time-to-live constant for not caching loaded resource bundle
2525          * instances.
2526          *
2527          * @see #getTimeToLive(String, Locale)
2528          */
2529         public static final long TTL_DONT_CACHE = -1;
2530 
2531         /**
2532          * The time-to-live constant for disabling the expiration control
2533          * for loaded resource bundle instances in the cache.
2534          *
2535          * @see #getTimeToLive(String, Locale)
2536          */
2537         public static final long TTL_NO_EXPIRATION_CONTROL = -2;
2538 
2539         private static final Control INSTANCE = new Control();
2540 
2541         /**
2542          * Sole constructor. (For invocation by subclass constructors,
2543          * typically implicit.)
2544          */
2545         protected Control() {
2546         }
2547 
2548         /**
2549          * Returns a <code>ResourceBundle.Control</code> in which the {@link
2550          * #getFormats(String) getFormats} method returns the specified
2551          * <code>formats</code>. The <code>formats</code> must be equal to
2552          * one of {@link Control#FORMAT_PROPERTIES}, {@link
2553          * Control#FORMAT_CLASS} or {@link
2554          * Control#FORMAT_DEFAULT}. <code>ResourceBundle.Control</code>
2555          * instances returned by this method are singletons and thread-safe.
2556          *
2557          * <p>Specifying {@link Control#FORMAT_DEFAULT} is equivalent to
2558          * instantiating the <code>ResourceBundle.Control</code> class,
2559          * except that this method returns a singleton.
2560          *
2561          * @param formats
2562          *        the formats to be returned by the
2563          *        <code>ResourceBundle.Control.getFormats</code> method
2564          * @return a <code>ResourceBundle.Control</code> supporting the
2565          *        specified <code>formats</code>
2566          * @exception NullPointerException
2567          *        if <code>formats</code> is <code>null</code>
2568          * @exception IllegalArgumentException
2569          *        if <code>formats</code> is unknown
2570          */
2571         public static final Control getControl(List<String> formats) {
2572             if (formats.equals(Control.FORMAT_PROPERTIES)) {
2573                 return SingleFormatControl.PROPERTIES_ONLY;
2574             }
2575             if (formats.equals(Control.FORMAT_CLASS)) {
2576                 return SingleFormatControl.CLASS_ONLY;
2577             }
2578             if (formats.equals(Control.FORMAT_DEFAULT)) {
2579                 return Control.INSTANCE;
2580             }
2581             throw new IllegalArgumentException();
2582         }
2583 
2584         /**
2585          * Returns a <code>ResourceBundle.Control</code> in which the {@link
2586          * #getFormats(String) getFormats} method returns the specified
2587          * <code>formats</code> and the {@link
2588          * Control#getFallbackLocale(String, Locale) getFallbackLocale}
2589          * method returns <code>null</code>. The <code>formats</code> must
2590          * be equal to one of {@link Control#FORMAT_PROPERTIES}, {@link
2591          * Control#FORMAT_CLASS} or {@link Control#FORMAT_DEFAULT}.
2592          * <code>ResourceBundle.Control</code> instances returned by this
2593          * method are singletons and thread-safe.
2594          *
2595          * @param formats
2596          *        the formats to be returned by the
2597          *        <code>ResourceBundle.Control.getFormats</code> method
2598          * @return a <code>ResourceBundle.Control</code> supporting the
2599          *        specified <code>formats</code> with no fallback
2600          *        <code>Locale</code> support
2601          * @exception NullPointerException
2602          *        if <code>formats</code> is <code>null</code>
2603          * @exception IllegalArgumentException
2604          *        if <code>formats</code> is unknown
2605          */
2606         public static final Control getNoFallbackControl(List<String> formats) {
2607             if (formats.equals(Control.FORMAT_DEFAULT)) {
2608                 return NoFallbackControl.NO_FALLBACK;
2609             }
2610             if (formats.equals(Control.FORMAT_PROPERTIES)) {
2611                 return NoFallbackControl.PROPERTIES_ONLY_NO_FALLBACK;
2612             }
2613             if (formats.equals(Control.FORMAT_CLASS)) {
2614                 return NoFallbackControl.CLASS_ONLY_NO_FALLBACK;
2615             }
2616             throw new IllegalArgumentException();
2617         }
2618 
2619         /**
2620          * Returns a <code>List</code> of <code>String</code>s containing
2621          * formats to be used to load resource bundles for the given
2622          * <code>baseName</code>. The <code>ResourceBundle.getBundle</code>
2623          * factory method tries to load resource bundles with formats in the
2624          * order specified by the list. The list returned by this method
2625          * must have at least one <code>String</code>. The predefined
2626          * formats are <code>"java.class"</code> for class-based resource
2627          * bundles and <code>"java.properties"</code> for {@linkplain
2628          * PropertyResourceBundle properties-based} ones. Strings starting
2629          * with <code>"java."</code> are reserved for future extensions and
2630          * must not be used by application-defined formats.
2631          *
2632          * <p>It is not a requirement to return an immutable (unmodifiable)
2633          * <code>List</code>.  However, the returned <code>List</code> must
2634          * not be mutated after it has been returned by
2635          * <code>getFormats</code>.
2636          *
2637          * <p>The default implementation returns {@link #FORMAT_DEFAULT} so
2638          * that the <code>ResourceBundle.getBundle</code> factory method
2639          * looks up first class-based resource bundles, then
2640          * properties-based ones.
2641          *
2642          * @param baseName
2643          *        the base name of the resource bundle, a fully qualified class
2644          *        name
2645          * @return a <code>List</code> of <code>String</code>s containing
2646          *        formats for loading resource bundles.
2647          * @exception NullPointerException
2648          *        if <code>baseName</code> is null
2649          * @see #FORMAT_DEFAULT
2650          * @see #FORMAT_CLASS
2651          * @see #FORMAT_PROPERTIES
2652          */
2653         public List<String> getFormats(String baseName) {
2654             if (baseName == null) {
2655                 throw new NullPointerException();
2656             }
2657             return FORMAT_DEFAULT;
2658         }
2659 
2660         /**
2661          * Returns a <code>List</code> of <code>Locale</code>s as candidate
2662          * locales for <code>baseName</code> and <code>locale</code>. This
2663          * method is called by the <code>ResourceBundle.getBundle</code>
2664          * factory method each time the factory method tries finding a
2665          * resource bundle for a target <code>Locale</code>.
2666          *
2667          * <p>The sequence of the candidate locales also corresponds to the
2668          * runtime resource lookup path (also known as the <I>parent
2669          * chain</I>), if the corresponding resource bundles for the
2670          * candidate locales exist and their parents are not defined by
2671          * loaded resource bundles themselves.  The last element of the list
2672          * must be a {@linkplain Locale#ROOT root locale} if it is desired to
2673          * have the base bundle as the terminal of the parent chain.
2674          *
2675          * <p>If the given locale is equal to <code>Locale.ROOT</code> (the
2676          * root locale), a <code>List</code> containing only the root
2677          * <code>Locale</code> must be returned. In this case, the
2678          * <code>ResourceBundle.getBundle</code> factory method loads only
2679          * the base bundle as the resulting resource bundle.
2680          *
2681          * <p>It is not a requirement to return an immutable (unmodifiable)
2682          * <code>List</code>. However, the returned <code>List</code> must not
2683          * be mutated after it has been returned by
2684          * <code>getCandidateLocales</code>.
2685          *
2686          * <p>The default implementation returns a <code>List</code> containing
2687          * <code>Locale</code>s using the rules described below.  In the
2688          * description below, <em>L</em>, <em>S</em>, <em>C</em> and <em>V</em>
2689          * respectively represent non-empty language, script, country, and
2690          * variant.  For example, [<em>L</em>, <em>C</em>] represents a
2691          * <code>Locale</code> that has non-empty values only for language and
2692          * country.  The form <em>L</em>("xx") represents the (non-empty)
2693          * language value is "xx".  For all cases, <code>Locale</code>s whose
2694          * final component values are empty strings are omitted.
2695          *
2696          * <ol><li>For an input <code>Locale</code> with an empty script value,
2697          * append candidate <code>Locale</code>s by omitting the final component
2698          * one by one as below:
2699          *
2700          * <ul>
2701          * <li> [<em>L</em>, <em>C</em>, <em>V</em>] </li>
2702          * <li> [<em>L</em>, <em>C</em>] </li>
2703          * <li> [<em>L</em>] </li>
2704          * <li> <code>Locale.ROOT</code> </li>
2705          * </ul></li>
2706          *
2707          * <li>For an input <code>Locale</code> with a non-empty script value,
2708          * append candidate <code>Locale</code>s by omitting the final component
2709          * up to language, then append candidates generated from the
2710          * <code>Locale</code> with country and variant restored:
2711          *
2712          * <ul>
2713          * <li> [<em>L</em>, <em>S</em>, <em>C</em>, <em>V</em>]</li>
2714          * <li> [<em>L</em>, <em>S</em>, <em>C</em>]</li>
2715          * <li> [<em>L</em>, <em>S</em>]</li>
2716          * <li> [<em>L</em>, <em>C</em>, <em>V</em>]</li>
2717          * <li> [<em>L</em>, <em>C</em>]</li>
2718          * <li> [<em>L</em>]</li>
2719          * <li> <code>Locale.ROOT</code></li>
2720          * </ul></li>
2721          *
2722          * <li>For an input <code>Locale</code> with a variant value consisting
2723          * of multiple subtags separated by underscore, generate candidate
2724          * <code>Locale</code>s by omitting the variant subtags one by one, then
2725          * insert them after every occurrence of <code> Locale</code>s with the
2726          * full variant value in the original list.  For example, if the
2727          * the variant consists of two subtags <em>V1</em> and <em>V2</em>:
2728          *
2729          * <ul>
2730          * <li> [<em>L</em>, <em>S</em>, <em>C</em>, <em>V1</em>, <em>V2</em>]</li>
2731          * <li> [<em>L</em>, <em>S</em>, <em>C</em>, <em>V1</em>]</li>
2732          * <li> [<em>L</em>, <em>S</em>, <em>C</em>]</li>
2733          * <li> [<em>L</em>, <em>S</em>]</li>
2734          * <li> [<em>L</em>, <em>C</em>, <em>V1</em>, <em>V2</em>]</li>
2735          * <li> [<em>L</em>, <em>C</em>, <em>V1</em>]</li>
2736          * <li> [<em>L</em>, <em>C</em>]</li>
2737          * <li> [<em>L</em>]</li>
2738          * <li> <code>Locale.ROOT</code></li>
2739          * </ul></li>
2740          *
2741          * <li>Special cases for Chinese.  When an input <code>Locale</code> has the
2742          * language "zh" (Chinese) and an empty script value, either "Hans" (Simplified) or
2743          * "Hant" (Traditional) might be supplied, depending on the country.
2744          * When the country is "CN" (China) or "SG" (Singapore), "Hans" is supplied.
2745          * When the country is "HK" (Hong Kong SAR China), "MO" (Macau SAR China),
2746          * or "TW" (Taiwan), "Hant" is supplied.  For all other countries or when the country
2747          * is empty, no script is supplied.  For example, for <code>Locale("zh", "CN")
2748          * </code>, the candidate list will be:
2749          * <ul>
2750          * <li> [<em>L</em>("zh"), <em>S</em>("Hans"), <em>C</em>("CN")]</li>
2751          * <li> [<em>L</em>("zh"), <em>S</em>("Hans")]</li>
2752          * <li> [<em>L</em>("zh"), <em>C</em>("CN")]</li>
2753          * <li> [<em>L</em>("zh")]</li>
2754          * <li> <code>Locale.ROOT</code></li>
2755          * </ul>
2756          *
2757          * For <code>Locale("zh", "TW")</code>, the candidate list will be:
2758          * <ul>
2759          * <li> [<em>L</em>("zh"), <em>S</em>("Hant"), <em>C</em>("TW")]</li>
2760          * <li> [<em>L</em>("zh"), <em>S</em>("Hant")]</li>
2761          * <li> [<em>L</em>("zh"), <em>C</em>("TW")]</li>
2762          * <li> [<em>L</em>("zh")]</li>
2763          * <li> <code>Locale.ROOT</code></li>
2764          * </ul></li>
2765          *
2766          * <li>Special cases for Norwegian.  Both <code>Locale("no", "NO",
2767          * "NY")</code> and <code>Locale("nn", "NO")</code> represent Norwegian
2768          * Nynorsk.  When a locale's language is "nn", the standard candidate
2769          * list is generated up to [<em>L</em>("nn")], and then the following
2770          * candidates are added:
2771          *
2772          * <ul><li> [<em>L</em>("no"), <em>C</em>("NO"), <em>V</em>("NY")]</li>
2773          * <li> [<em>L</em>("no"), <em>C</em>("NO")]</li>
2774          * <li> [<em>L</em>("no")]</li>
2775          * <li> <code>Locale.ROOT</code></li>
2776          * </ul>
2777          *
2778          * If the locale is exactly <code>Locale("no", "NO", "NY")</code>, it is first
2779          * converted to <code>Locale("nn", "NO")</code> and then the above procedure is
2780          * followed.
2781          *
2782          * <p>Also, Java treats the language "no" as a synonym of Norwegian
2783          * Bokmål "nb".  Except for the single case <code>Locale("no",
2784          * "NO", "NY")</code> (handled above), when an input <code>Locale</code>
2785          * has language "no" or "nb", candidate <code>Locale</code>s with
2786          * language code "no" and "nb" are interleaved, first using the
2787          * requested language, then using its synonym. For example,
2788          * <code>Locale("nb", "NO", "POSIX")</code> generates the following
2789          * candidate list:
2790          *
2791          * <ul>
2792          * <li> [<em>L</em>("nb"), <em>C</em>("NO"), <em>V</em>("POSIX")]</li>
2793          * <li> [<em>L</em>("no"), <em>C</em>("NO"), <em>V</em>("POSIX")]</li>
2794          * <li> [<em>L</em>("nb"), <em>C</em>("NO")]</li>
2795          * <li> [<em>L</em>("no"), <em>C</em>("NO")]</li>
2796          * <li> [<em>L</em>("nb")]</li>
2797          * <li> [<em>L</em>("no")]</li>
2798          * <li> <code>Locale.ROOT</code></li>
2799          * </ul>
2800          *
2801          * <code>Locale("no", "NO", "POSIX")</code> would generate the same list
2802          * except that locales with "no" would appear before the corresponding
2803          * locales with "nb".</li>
2804          * </ol>
2805          *
2806          * <p>The default implementation uses an {@link ArrayList} that
2807          * overriding implementations may modify before returning it to the
2808          * caller. However, a subclass must not modify it after it has
2809          * been returned by <code>getCandidateLocales</code>.
2810          *
2811          * <p>For example, if the given <code>baseName</code> is "Messages"
2812          * and the given <code>locale</code> is
2813          * <code>Locale("ja",&nbsp;"",&nbsp;"XX")</code>, then a
2814          * <code>List</code> of <code>Locale</code>s:
2815          * <pre>
2816          *     Locale("ja", "", "XX")
2817          *     Locale("ja")
2818          *     Locale.ROOT
2819          * </pre>
2820          * is returned. And if the resource bundles for the "ja" and
2821          * "" <code>Locale</code>s are found, then the runtime resource
2822          * lookup path (parent chain) is:
2823          * <pre>{@code
2824          *     Messages_ja -> Messages
2825          * }</pre>
2826          *
2827          * @param baseName
2828          *        the base name of the resource bundle, a fully
2829          *        qualified class name
2830          * @param locale
2831          *        the locale for which a resource bundle is desired
2832          * @return a <code>List</code> of candidate
2833          *        <code>Locale</code>s for the given <code>locale</code>
2834          * @exception NullPointerException
2835          *        if <code>baseName</code> or <code>locale</code> is
2836          *        <code>null</code>
2837          */
2838         public List<Locale> getCandidateLocales(String baseName, Locale locale) {
2839             if (baseName == null) {
2840                 throw new NullPointerException();
2841             }
2842             return new ArrayList<>(CANDIDATES_CACHE.get(locale.getBaseLocale()));
2843         }
2844 
2845         private static final CandidateListCache CANDIDATES_CACHE = new CandidateListCache();
2846 
2847         private static class CandidateListCache extends LocaleObjectCache<BaseLocale, List<Locale>> {
2848             protected List<Locale> createObject(BaseLocale base) {
2849                 String language = base.getLanguage();
2850                 String script = base.getScript();
2851                 String region = base.getRegion();
2852                 String variant = base.getVariant();
2853 
2854                 // Special handling for Norwegian
2855                 boolean isNorwegianBokmal = false;
2856                 boolean isNorwegianNynorsk = false;
2857                 if (language.equals("no")) {
2858                     if (region.equals("NO") && variant.equals("NY")) {
2859                         variant = "";
2860                         isNorwegianNynorsk = true;
2861                     } else {
2862                         isNorwegianBokmal = true;
2863                     }
2864                 }
2865                 if (language.equals("nb") || isNorwegianBokmal) {
2866                     List<Locale> tmpList = getDefaultList("nb", script, region, variant);
2867                     // Insert a locale replacing "nb" with "no" for every list entry
2868                     List<Locale> bokmalList = new LinkedList<>();
2869                     for (Locale l : tmpList) {
2870                         bokmalList.add(l);
2871                         if (l.getLanguage().length() == 0) {
2872                             break;
2873                         }
2874                         bokmalList.add(Locale.getInstance("no", l.getScript(), l.getCountry(),
2875                                 l.getVariant(), null));
2876                     }
2877                     return bokmalList;
2878                 } else if (language.equals("nn") || isNorwegianNynorsk) {
2879                     // Insert no_NO_NY, no_NO, no after nn
2880                     List<Locale> nynorskList = getDefaultList("nn", script, region, variant);
2881                     int idx = nynorskList.size() - 1;
2882                     nynorskList.add(idx++, Locale.getInstance("no", "NO", "NY"));
2883                     nynorskList.add(idx++, Locale.getInstance("no", "NO", ""));
2884                     nynorskList.add(idx++, Locale.getInstance("no", "", ""));
2885                     return nynorskList;
2886                 }
2887                 // Special handling for Chinese
2888                 else if (language.equals("zh")) {
2889                     if (script.length() == 0 && region.length() > 0) {
2890                         // Supply script for users who want to use zh_Hans/zh_Hant
2891                         // as bundle names (recommended for Java7+)
2892                         switch (region) {
2893                         case "TW":
2894                         case "HK":
2895                         case "MO":
2896                             script = "Hant";
2897                             break;
2898                         case "CN":
2899                         case "SG":
2900                             script = "Hans";
2901                             break;
2902                         }
2903                     } else if (script.length() > 0 && region.length() == 0) {
2904                         // Supply region(country) for users who still package Chinese
2905                         // bundles using old convension.
2906                         switch (script) {
2907                         case "Hans":
2908                             region = "CN";
2909                             break;
2910                         case "Hant":
2911                             region = "TW";
2912                             break;
2913                         }
2914                     }
2915                 }
2916 
2917                 return getDefaultList(language, script, region, variant);
2918             }
2919 
2920             private static List<Locale> getDefaultList(String language, String script, String region, String variant) {
2921                 List<String> variants = null;
2922 
2923                 if (variant.length() > 0) {
2924                     variants = new LinkedList<>();
2925                     int idx = variant.length();
2926                     while (idx != -1) {
2927                         variants.add(variant.substring(0, idx));
2928                         idx = variant.lastIndexOf('_', --idx);
2929                     }
2930                 }
2931 
2932                 List<Locale> list = new LinkedList<>();
2933 
2934                 if (variants != null) {
2935                     for (String v : variants) {
2936                         list.add(Locale.getInstance(language, script, region, v, null));
2937                     }
2938                 }
2939                 if (region.length() > 0) {
2940                     list.add(Locale.getInstance(language, script, region, "", null));
2941                 }
2942                 if (script.length() > 0) {
2943                     list.add(Locale.getInstance(language, script, "", "", null));
2944 
2945                     // With script, after truncating variant, region and script,
2946                     // start over without script.
2947                     if (variants != null) {
2948                         for (String v : variants) {
2949                             list.add(Locale.getInstance(language, "", region, v, null));
2950                         }
2951                     }
2952                     if (region.length() > 0) {
2953                         list.add(Locale.getInstance(language, "", region, "", null));
2954                     }
2955                 }
2956                 if (language.length() > 0) {
2957                     list.add(Locale.getInstance(language, "", "", "", null));
2958                 }
2959                 // Add root locale at the end
2960                 list.add(Locale.ROOT);
2961 
2962                 return list;
2963             }
2964         }
2965 
2966         /**
2967          * Returns a <code>Locale</code> to be used as a fallback locale for
2968          * further resource bundle searches by the
2969          * <code>ResourceBundle.getBundle</code> factory method. This method
2970          * is called from the factory method every time when no resulting
2971          * resource bundle has been found for <code>baseName</code> and
2972          * <code>locale</code>, where locale is either the parameter for
2973          * <code>ResourceBundle.getBundle</code> or the previous fallback
2974          * locale returned by this method.
2975          *
2976          * <p>The method returns <code>null</code> if no further fallback
2977          * search is desired.
2978          *
2979          * <p>The default implementation returns the {@linkplain
2980          * Locale#getDefault() default <code>Locale</code>} if the given
2981          * <code>locale</code> isn't the default one.  Otherwise,
2982          * <code>null</code> is returned.
2983          *
2984          * @param baseName
2985          *        the base name of the resource bundle, a fully
2986          *        qualified class name for which
2987          *        <code>ResourceBundle.getBundle</code> has been
2988          *        unable to find any resource bundles (except for the
2989          *        base bundle)
2990          * @param locale
2991          *        the <code>Locale</code> for which
2992          *        <code>ResourceBundle.getBundle</code> has been
2993          *        unable to find any resource bundles (except for the
2994          *        base bundle)
2995          * @return a <code>Locale</code> for the fallback search,
2996          *        or <code>null</code> if no further fallback search
2997          *        is desired.
2998          * @exception NullPointerException
2999          *        if <code>baseName</code> or <code>locale</code>
3000          *        is <code>null</code>
3001          */
3002         public Locale getFallbackLocale(String baseName, Locale locale) {
3003             if (baseName == null) {
3004                 throw new NullPointerException();
3005             }
3006             Locale defaultLocale = Locale.getDefault();
3007             return locale.equals(defaultLocale) ? null : defaultLocale;
3008         }
3009 
3010         /**
3011          * Instantiates a resource bundle for the given bundle name of the
3012          * given format and locale, using the given class loader if
3013          * necessary. This method returns <code>null</code> if there is no
3014          * resource bundle available for the given parameters. If a resource
3015          * bundle can't be instantiated due to an unexpected error, the
3016          * error must be reported by throwing an <code>Error</code> or
3017          * <code>Exception</code> rather than simply returning
3018          * <code>null</code>.
3019          *
3020          * <p>If the <code>reload</code> flag is <code>true</code>, it
3021          * indicates that this method is being called because the previously
3022          * loaded resource bundle has expired.
3023          *
3024          * <p>The default implementation instantiates a
3025          * <code>ResourceBundle</code> as follows.
3026          *
3027          * <ul>
3028          *
3029          * <li>The bundle name is obtained by calling {@link
3030          * #toBundleName(String, Locale) toBundleName(baseName,
3031          * locale)}.</li>
3032          *
3033          * <li>If <code>format</code> is <code>"java.class"</code>, the
3034          * {@link Class} specified by the bundle name is loaded by calling
3035          * {@link ClassLoader#loadClass(String)}. Then, a
3036          * <code>ResourceBundle</code> is instantiated by calling {@link
3037          * Class#newInstance()}.  Note that the <code>reload</code> flag is
3038          * ignored for loading class-based resource bundles in this default
3039          * implementation.</li>
3040          *
3041          * <li>If <code>format</code> is <code>"java.properties"</code>,
3042          * {@link #toResourceName(String, String) toResourceName(bundlename,
3043          * "properties")} is called to get the resource name.
3044          * If <code>reload</code> is <code>true</code>, {@link
3045          * ClassLoader#getResource(String) load.getResource} is called
3046          * to get a {@link URL} for creating a {@link
3047          * URLConnection}. This <code>URLConnection</code> is used to
3048          * {@linkplain URLConnection#setUseCaches(boolean) disable the
3049          * caches} of the underlying resource loading layers,
3050          * and to {@linkplain URLConnection#getInputStream() get an
3051          * <code>InputStream</code>}.
3052          * Otherwise, {@link ClassLoader#getResourceAsStream(String)
3053          * loader.getResourceAsStream} is called to get an {@link
3054          * InputStream}. Then, a {@link
3055          * PropertyResourceBundle} is constructed with the
3056          * <code>InputStream</code>.</li>
3057          *
3058          * <li>If <code>format</code> is neither <code>"java.class"</code>
3059          * nor <code>"java.properties"</code>, an
3060          * <code>IllegalArgumentException</code> is thrown.</li>
3061          *
3062          * </ul>
3063          *
3064          * @param baseName
3065          *        the base bundle name of the resource bundle, a fully
3066          *        qualified class name
3067          * @param locale
3068          *        the locale for which the resource bundle should be
3069          *        instantiated
3070          * @param format
3071          *        the resource bundle format to be loaded
3072          * @param loader
3073          *        the <code>ClassLoader</code> to use to load the bundle
3074          * @param reload
3075          *        the flag to indicate bundle reloading; <code>true</code>
3076          *        if reloading an expired resource bundle,
3077          *        <code>false</code> otherwise
3078          * @return the resource bundle instance,
3079          *        or <code>null</code> if none could be found.
3080          * @exception NullPointerException
3081          *        if <code>bundleName</code>, <code>locale</code>,
3082          *        <code>format</code>, or <code>loader</code> is
3083          *        <code>null</code>, or if <code>null</code> is returned by
3084          *        {@link #toBundleName(String, Locale) toBundleName}
3085          * @exception IllegalArgumentException
3086          *        if <code>format</code> is unknown, or if the resource
3087          *        found for the given parameters contains malformed data.
3088          * @exception ClassCastException
3089          *        if the loaded class cannot be cast to <code>ResourceBundle</code>
3090          * @exception IllegalAccessException
3091          *        if the class or its nullary constructor is not
3092          *        accessible.
3093          * @exception InstantiationException
3094          *        if the instantiation of a class fails for some other
3095          *        reason.
3096          * @exception ExceptionInInitializerError
3097          *        if the initialization provoked by this method fails.
3098          * @exception SecurityException
3099          *        If a security manager is present and creation of new
3100          *        instances is denied. See {@link Class#newInstance()}
3101          *        for details.
3102          * @exception IOException
3103          *        if an error occurred when reading resources using
3104          *        any I/O operations
3105          * @see java.util.spi.ResourceBundleProvider#getBundle(String, Locale)
3106          */
3107         public ResourceBundle newBundle(String baseName, Locale locale, String format,
3108                                         ClassLoader loader, boolean reload)
3109                     throws IllegalAccessException, InstantiationException, IOException {
3110             /*
3111              * Legacy mechanism to locate resource bundle in unnamed module only
3112              * that is visible to the given loader and accessible to the given caller.
3113              * This only finds resources on the class path but not in named modules.
3114              */
3115             String bundleName = toBundleName(baseName, locale);
3116             ResourceBundle bundle = null;
3117             if (format.equals("java.class")) {
3118                 try {
3119                     Class<?> c = loader.loadClass(bundleName);
3120                     // If the class isn't a ResourceBundle subclass, throw a
3121                     // ClassCastException.
3122                     if (ResourceBundle.class.isAssignableFrom(c)) {
3123                         @SuppressWarnings("unchecked")
3124                         Class<ResourceBundle> bundleClass = (Class<ResourceBundle>)c;
3125 
3126                         // This doesn't allow unnamed modules to find bundles in
3127                         // named modules other than via the service loader mechanism.
3128                         // Otherwise, this will make the newBundle method to be
3129                         // caller-sensitive in order to verify access check.
3130                         // So migrating resource bundles to named module can't
3131                         // just export the package (in general, legacy resource
3132                         // bundles have split package if they are packaged separate
3133                         // from the consumer.)
3134                         if (bundleClass.getModule().isNamed()) {
3135                             throw new IllegalAccessException("unnamed modules can't load " + bundleName
3136                                      + " in named module " + bundleClass.getModule().getName());
3137                         }
3138                         try {
3139                             // bundle in a unnamed module
3140                             Constructor<ResourceBundle> ctor = bundleClass.getConstructor();
3141                             if (!Modifier.isPublic(ctor.getModifiers())) {
3142                                 return null;
3143                             }
3144 
3145                             // java.base may not be able to read the bundleClass's module.
3146                             PrivilegedAction<Void> pa1 = () -> { ctor.setAccessible(true); return null; };
3147                             AccessController.doPrivileged(pa1);
3148                             bundle = ctor.newInstance((Object[]) null);
3149                         } catch (InvocationTargetException e) {
3150                             uncheckedThrow(e);
3151                         }
3152                     } else {
3153                         throw new ClassCastException(c.getName()
3154                                 + " cannot be cast to ResourceBundle");
3155                     }
3156                 } catch (ClassNotFoundException|NoSuchMethodException e) {
3157                 }
3158             } else if (format.equals("java.properties")) {
3159                 final String resourceName = toResourceName0(bundleName, "properties");
3160                 if (resourceName == null) {
3161                     return bundle;
3162                 }
3163 
3164                 final boolean reloadFlag = reload;
3165                 InputStream stream = null;
3166                 try {
3167                     stream = AccessController.doPrivileged(
3168                         new PrivilegedExceptionAction<>() {
3169                             public InputStream run() throws IOException {
3170                                 URL url = loader.getResource(resourceName);
3171                                 if (url == null) return null;
3172 
3173                                 URLConnection connection = url.openConnection();
3174                                 if (reloadFlag) {
3175                                     // Disable caches to get fresh data for
3176                                     // reloading.
3177                                     connection.setUseCaches(false);
3178                                 }
3179                                 return connection.getInputStream();
3180                             }
3181                         });
3182                 } catch (PrivilegedActionException e) {
3183                     throw (IOException) e.getException();
3184                 }
3185                 if (stream != null) {
3186                     try {
3187                         bundle = new PropertyResourceBundle(stream);
3188                     } finally {
3189                         stream.close();
3190                     }
3191                 }
3192             } else {
3193                 throw new IllegalArgumentException("unknown format: " + format);
3194             }
3195             return bundle;
3196         }
3197 
3198         /**
3199          * Returns the time-to-live (TTL) value for resource bundles that
3200          * are loaded under this
3201          * <code>ResourceBundle.Control</code>. Positive time-to-live values
3202          * specify the number of milliseconds a bundle can remain in the
3203          * cache without being validated against the source data from which
3204          * it was constructed. The value 0 indicates that a bundle must be
3205          * validated each time it is retrieved from the cache. {@link
3206          * #TTL_DONT_CACHE} specifies that loaded resource bundles are not
3207          * put in the cache. {@link #TTL_NO_EXPIRATION_CONTROL} specifies
3208          * that loaded resource bundles are put in the cache with no
3209          * expiration control.
3210          *
3211          * <p>The expiration affects only the bundle loading process by the
3212          * <code>ResourceBundle.getBundle</code> factory method.  That is,
3213          * if the factory method finds a resource bundle in the cache that
3214          * has expired, the factory method calls the {@link
3215          * #needsReload(String, Locale, String, ClassLoader, ResourceBundle,
3216          * long) needsReload} method to determine whether the resource
3217          * bundle needs to be reloaded. If <code>needsReload</code> returns
3218          * <code>true</code>, the cached resource bundle instance is removed
3219          * from the cache. Otherwise, the instance stays in the cache,
3220          * updated with the new TTL value returned by this method.
3221          *
3222          * <p>All cached resource bundles are subject to removal from the
3223          * cache due to memory constraints of the runtime environment.
3224          * Returning a large positive value doesn't mean to lock loaded
3225          * resource bundles in the cache.
3226          *
3227          * <p>The default implementation returns {@link #TTL_NO_EXPIRATION_CONTROL}.
3228          *
3229          * @param baseName
3230          *        the base name of the resource bundle for which the
3231          *        expiration value is specified.
3232          * @param locale
3233          *        the locale of the resource bundle for which the
3234          *        expiration value is specified.
3235          * @return the time (0 or a positive millisecond offset from the
3236          *        cached time) to get loaded bundles expired in the cache,
3237          *        {@link #TTL_NO_EXPIRATION_CONTROL} to disable the
3238          *        expiration control, or {@link #TTL_DONT_CACHE} to disable
3239          *        caching.
3240          * @exception NullPointerException
3241          *        if <code>baseName</code> or <code>locale</code> is
3242          *        <code>null</code>
3243          */
3244         public long getTimeToLive(String baseName, Locale locale) {
3245             if (baseName == null || locale == null) {
3246                 throw new NullPointerException();
3247             }
3248             return TTL_NO_EXPIRATION_CONTROL;
3249         }
3250 
3251         /**
3252          * Determines if the expired <code>bundle</code> in the cache needs
3253          * to be reloaded based on the loading time given by
3254          * <code>loadTime</code> or some other criteria. The method returns
3255          * <code>true</code> if reloading is required; <code>false</code>
3256          * otherwise. <code>loadTime</code> is a millisecond offset since
3257          * the <a href="Calendar.html#Epoch"> <code>Calendar</code>
3258          * Epoch</a>.
3259          *
3260          * <p>
3261          * The calling <code>ResourceBundle.getBundle</code> factory method
3262          * calls this method on the <code>ResourceBundle.Control</code>
3263          * instance used for its current invocation, not on the instance
3264          * used in the invocation that originally loaded the resource
3265          * bundle.
3266          *
3267          * <p>The default implementation compares <code>loadTime</code> and
3268          * the last modified time of the source data of the resource
3269          * bundle. If it's determined that the source data has been modified
3270          * since <code>loadTime</code>, <code>true</code> is
3271          * returned. Otherwise, <code>false</code> is returned. This
3272          * implementation assumes that the given <code>format</code> is the
3273          * same string as its file suffix if it's not one of the default
3274          * formats, <code>"java.class"</code> or
3275          * <code>"java.properties"</code>.
3276          *
3277          * @param baseName
3278          *        the base bundle name of the resource bundle, a
3279          *        fully qualified class name
3280          * @param locale
3281          *        the locale for which the resource bundle
3282          *        should be instantiated
3283          * @param format
3284          *        the resource bundle format to be loaded
3285          * @param loader
3286          *        the <code>ClassLoader</code> to use to load the bundle
3287          * @param bundle
3288          *        the resource bundle instance that has been expired
3289          *        in the cache
3290          * @param loadTime
3291          *        the time when <code>bundle</code> was loaded and put
3292          *        in the cache
3293          * @return <code>true</code> if the expired bundle needs to be
3294          *        reloaded; <code>false</code> otherwise.
3295          * @exception NullPointerException
3296          *        if <code>baseName</code>, <code>locale</code>,
3297          *        <code>format</code>, <code>loader</code>, or
3298          *        <code>bundle</code> is <code>null</code>
3299          */
3300         public boolean needsReload(String baseName, Locale locale,
3301                                    String format, ClassLoader loader,
3302                                    ResourceBundle bundle, long loadTime) {
3303             if (bundle == null) {
3304                 throw new NullPointerException();
3305             }
3306             if (format.equals("java.class") || format.equals("java.properties")) {
3307                 format = format.substring(5);
3308             }
3309             boolean result = false;
3310             try {
3311                 String resourceName = toResourceName0(toBundleName(baseName, locale), format);
3312                 if (resourceName == null) {
3313                     return result;
3314                 }
3315                 URL url = loader.getResource(resourceName);
3316                 if (url != null) {
3317                     long lastModified = 0;
3318                     URLConnection connection = url.openConnection();
3319                     if (connection != null) {
3320                         // disable caches to get the correct data
3321                         connection.setUseCaches(false);
3322                         if (connection instanceof JarURLConnection) {
3323                             JarEntry ent = ((JarURLConnection)connection).getJarEntry();
3324                             if (ent != null) {
3325                                 lastModified = ent.getTime();
3326                                 if (lastModified == -1) {
3327                                     lastModified = 0;
3328                                 }
3329                             }
3330                         } else {
3331                             lastModified = connection.getLastModified();
3332                         }
3333                     }
3334                     result = lastModified >= loadTime;
3335                 }
3336             } catch (NullPointerException npe) {
3337                 throw npe;
3338             } catch (Exception e) {
3339                 // ignore other exceptions
3340             }
3341             return result;
3342         }
3343 
3344         /**
3345          * Converts the given <code>baseName</code> and <code>locale</code>
3346          * to the bundle name. This method is called from the default
3347          * implementation of the {@link #newBundle(String, Locale, String,
3348          * ClassLoader, boolean) newBundle} and {@link #needsReload(String,
3349          * Locale, String, ClassLoader, ResourceBundle, long) needsReload}
3350          * methods.
3351          *
3352          * <p>This implementation returns the following value:
3353          * <pre>
3354          *     baseName + "_" + language + "_" + script + "_" + country + "_" + variant
3355          * </pre>
3356          * where <code>language</code>, <code>script</code>, <code>country</code>,
3357          * and <code>variant</code> are the language, script, country, and variant
3358          * values of <code>locale</code>, respectively. Final component values that
3359          * are empty Strings are omitted along with the preceding '_'.  When the
3360          * script is empty, the script value is omitted along with the preceding '_'.
3361          * If all of the values are empty strings, then <code>baseName</code>
3362          * is returned.
3363          *
3364          * <p>For example, if <code>baseName</code> is
3365          * <code>"baseName"</code> and <code>locale</code> is
3366          * <code>Locale("ja",&nbsp;"",&nbsp;"XX")</code>, then
3367          * <code>"baseName_ja_&thinsp;_XX"</code> is returned. If the given
3368          * locale is <code>Locale("en")</code>, then
3369          * <code>"baseName_en"</code> is returned.
3370          *
3371          * <p>Overriding this method allows applications to use different
3372          * conventions in the organization and packaging of localized
3373          * resources.
3374          *
3375          * @param baseName
3376          *        the base name of the resource bundle, a fully
3377          *        qualified class name
3378          * @param locale
3379          *        the locale for which a resource bundle should be
3380          *        loaded
3381          * @return the bundle name for the resource bundle
3382          * @exception NullPointerException
3383          *        if <code>baseName</code> or <code>locale</code>
3384          *        is <code>null</code>
3385          * @see java.util.spi.AbstractResourceBundleProvider#toBundleName(String, Locale)
3386          */
3387         public String toBundleName(String baseName, Locale locale) {
3388             if (locale == Locale.ROOT) {
3389                 return baseName;
3390             }
3391 
3392             String language = locale.getLanguage();
3393             String script = locale.getScript();
3394             String country = locale.getCountry();
3395             String variant = locale.getVariant();
3396 
3397             if (language == "" && country == "" && variant == "") {
3398                 return baseName;
3399             }
3400 
3401             StringBuilder sb = new StringBuilder(baseName);
3402             sb.append('_');
3403             if (script != "") {
3404                 if (variant != "") {
3405                     sb.append(language).append('_').append(script).append('_').append(country).append('_').append(variant);
3406                 } else if (country != "") {
3407                     sb.append(language).append('_').append(script).append('_').append(country);
3408                 } else {
3409                     sb.append(language).append('_').append(script);
3410                 }
3411             } else {
3412                 if (variant != "") {
3413                     sb.append(language).append('_').append(country).append('_').append(variant);
3414                 } else if (country != "") {
3415                     sb.append(language).append('_').append(country);
3416                 } else {
3417                     sb.append(language);
3418                 }
3419             }
3420             return sb.toString();
3421 
3422         }
3423 
3424         /**
3425          * Converts the given <code>bundleName</code> to the form required
3426          * by the {@link ClassLoader#getResource ClassLoader.getResource}
3427          * method by replacing all occurrences of <code>'.'</code> in
3428          * <code>bundleName</code> with <code>'/'</code> and appending a
3429          * <code>'.'</code> and the given file <code>suffix</code>. For
3430          * example, if <code>bundleName</code> is
3431          * <code>"foo.bar.MyResources_ja_JP"</code> and <code>suffix</code>
3432          * is <code>"properties"</code>, then
3433          * <code>"foo/bar/MyResources_ja_JP.properties"</code> is returned.
3434          *
3435          * @param bundleName
3436          *        the bundle name
3437          * @param suffix
3438          *        the file type suffix
3439          * @return the converted resource name
3440          * @exception NullPointerException
3441          *         if <code>bundleName</code> or <code>suffix</code>
3442          *         is <code>null</code>
3443          */
3444         public final String toResourceName(String bundleName, String suffix) {
3445             StringBuilder sb = new StringBuilder(bundleName.length() + 1 + suffix.length());
3446             sb.append(bundleName.replace('.', '/')).append('.').append(suffix);
3447             return sb.toString();
3448         }
3449 
3450         private String toResourceName0(String bundleName, String suffix) {
3451             // application protocol check
3452             if (bundleName.contains("://")) {
3453                 return null;
3454             } else {
3455                 return toResourceName(bundleName, suffix);
3456             }
3457         }
3458     }
3459 
3460     @SuppressWarnings("unchecked")
3461     private static <T extends Throwable> void uncheckedThrow(Throwable t) throws T {
3462         if (t != null)
3463             throw (T)t;
3464         else
3465             throw new Error("Unknown Exception");
3466     }
3467 
3468     private static class SingleFormatControl extends Control {
3469         private static final Control PROPERTIES_ONLY
3470             = new SingleFormatControl(FORMAT_PROPERTIES);
3471 
3472         private static final Control CLASS_ONLY
3473             = new SingleFormatControl(FORMAT_CLASS);
3474 
3475         private final List<String> formats;
3476 
3477         protected SingleFormatControl(List<String> formats) {
3478             this.formats = formats;
3479         }
3480 
3481         public List<String> getFormats(String baseName) {
3482             if (baseName == null) {
3483                 throw new NullPointerException();
3484             }
3485             return formats;
3486         }
3487     }
3488 
3489     private static final class NoFallbackControl extends SingleFormatControl {
3490         private static final Control NO_FALLBACK
3491             = new NoFallbackControl(FORMAT_DEFAULT);
3492 
3493         private static final Control PROPERTIES_ONLY_NO_FALLBACK
3494             = new NoFallbackControl(FORMAT_PROPERTIES);
3495 
3496         private static final Control CLASS_ONLY_NO_FALLBACK
3497             = new NoFallbackControl(FORMAT_CLASS);
3498 
3499         protected NoFallbackControl(List<String> formats) {
3500             super(formats);
3501         }
3502 
3503         public Locale getFallbackLocale(String baseName, Locale locale) {
3504             if (baseName == null || locale == null) {
3505                 throw new NullPointerException();
3506             }
3507             return null;
3508         }
3509     }
3510 }