0001: /*
0002: * Copyright 1996-2006 Sun Microsystems, Inc. All Rights Reserved.
0003: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0004: *
0005: * This code is free software; you can redistribute it and/or modify it
0006: * under the terms of the GNU General Public License version 2 only, as
0007: * published by the Free Software Foundation. Sun designates this
0008: * particular file as subject to the "Classpath" exception as provided
0009: * by Sun in the LICENSE file that accompanied this code.
0010: *
0011: * This code is distributed in the hope that it will be useful, but WITHOUT
0012: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0013: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0014: * version 2 for more details (a copy is included in the LICENSE file that
0015: * accompanied this code).
0016: *
0017: * You should have received a copy of the GNU General Public License version
0018: * 2 along with this work; if not, write to the Free Software Foundation,
0019: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0020: *
0021: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
0022: * CA 95054 USA or visit www.sun.com if you need additional information or
0023: * have any questions.
0024: */
0025:
0026: /*
0027: * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
0028: * (C) Copyright IBM Corp. 1996 - 1999 - All Rights Reserved
0029: *
0030: * The original version of this source code and documentation
0031: * is copyrighted and owned by Taligent, Inc., a wholly-owned
0032: * subsidiary of IBM. These materials are provided under terms
0033: * of a License Agreement between Taligent and Sun. This technology
0034: * is protected by multiple US and International patents.
0035: *
0036: * This notice and attribution to Taligent may not be removed.
0037: * Taligent is a registered trademark of Taligent, Inc.
0038: *
0039: */
0040:
0041: package java.util;
0042:
0043: import java.io.IOException;
0044: import java.io.InputStream;
0045: import java.lang.ref.ReferenceQueue;
0046: import java.lang.ref.SoftReference;
0047: import java.lang.ref.WeakReference;
0048: import java.net.JarURLConnection;
0049: import java.net.URL;
0050: import java.net.URLConnection;
0051: import java.security.AccessController;
0052: import java.security.PrivilegedAction;
0053: import java.security.PrivilegedActionException;
0054: import java.security.PrivilegedExceptionAction;
0055: import java.util.concurrent.ConcurrentHashMap;
0056: import java.util.concurrent.ConcurrentMap;
0057: import java.util.jar.JarEntry;
0058:
0059: /**
0060: *
0061: * Resource bundles contain locale-specific objects.
0062: * When your program needs a locale-specific resource,
0063: * a <code>String</code> for example, your program can load it
0064: * from the resource bundle that is appropriate for the
0065: * current user's locale. In this way, you can write
0066: * program code that is largely independent of the user's
0067: * locale isolating most, if not all, of the locale-specific
0068: * information in resource bundles.
0069: *
0070: * <p>
0071: * This allows you to write programs that can:
0072: * <UL type=SQUARE>
0073: * <LI> be easily localized, or translated, into different languages
0074: * <LI> handle multiple locales at once
0075: * <LI> be easily modified later to support even more locales
0076: * </UL>
0077: *
0078: * <P>
0079: * Resource bundles belong to families whose members share a common base
0080: * name, but whose names also have additional components that identify
0081: * their locales. For example, the base name of a family of resource
0082: * bundles might be "MyResources". The family should have a default
0083: * resource bundle which simply has the same name as its family -
0084: * "MyResources" - and will be used as the bundle of last resort if a
0085: * specific locale is not supported. The family can then provide as
0086: * many locale-specific members as needed, for example a German one
0087: * named "MyResources_de".
0088: *
0089: * <P>
0090: * Each resource bundle in a family contains the same items, but the items have
0091: * been translated for the locale represented by that resource bundle.
0092: * For example, both "MyResources" and "MyResources_de" may have a
0093: * <code>String</code> that's used on a button for canceling operations.
0094: * In "MyResources" the <code>String</code> may contain "Cancel" and in
0095: * "MyResources_de" it may contain "Abbrechen".
0096: *
0097: * <P>
0098: * If there are different resources for different countries, you
0099: * can make specializations: for example, "MyResources_de_CH" contains objects for
0100: * the German language (de) in Switzerland (CH). If you want to only
0101: * modify some of the resources
0102: * in the specialization, you can do so.
0103: *
0104: * <P>
0105: * When your program needs a locale-specific object, it loads
0106: * the <code>ResourceBundle</code> class using the
0107: * {@link #getBundle(java.lang.String, java.util.Locale) getBundle}
0108: * method:
0109: * <blockquote>
0110: * <pre>
0111: * ResourceBundle myResources =
0112: * ResourceBundle.getBundle("MyResources", currentLocale);
0113: * </pre>
0114: * </blockquote>
0115: *
0116: * <P>
0117: * Resource bundles contain key/value pairs. The keys uniquely
0118: * identify a locale-specific object in the bundle. Here's an
0119: * example of a <code>ListResourceBundle</code> that contains
0120: * two key/value pairs:
0121: * <blockquote>
0122: * <pre>
0123: * public class MyResources extends ListResourceBundle {
0124: * protected Object[][] getContents() {
0125: * return new Object[][] {
0126: * // LOCALIZE THE SECOND STRING OF EACH ARRAY (e.g., "OK")
0127: * {"OkKey", "OK"},
0128: * {"CancelKey", "Cancel"},
0129: * // END OF MATERIAL TO LOCALIZE
0130: * };
0131: * }
0132: * }
0133: * </pre>
0134: * </blockquote>
0135: * Keys are always <code>String</code>s.
0136: * In this example, the keys are "OkKey" and "CancelKey".
0137: * In the above example, the values
0138: * are also <code>String</code>s--"OK" and "Cancel"--but
0139: * they don't have to be. The values can be any type of object.
0140: *
0141: * <P>
0142: * You retrieve an object from resource bundle using the appropriate
0143: * getter method. Because "OkKey" and "CancelKey"
0144: * are both strings, you would use <code>getString</code> to retrieve them:
0145: * <blockquote>
0146: * <pre>
0147: * button1 = new Button(myResources.getString("OkKey"));
0148: * button2 = new Button(myResources.getString("CancelKey"));
0149: * </pre>
0150: * </blockquote>
0151: * The getter methods all require the key as an argument and return
0152: * the object if found. If the object is not found, the getter method
0153: * throws a <code>MissingResourceException</code>.
0154: *
0155: * <P>
0156: * Besides <code>getString</code>, <code>ResourceBundle</code> also provides
0157: * a method for getting string arrays, <code>getStringArray</code>,
0158: * as well as a generic <code>getObject</code> method for any other
0159: * type of object. When using <code>getObject</code>, you'll
0160: * have to cast the result to the appropriate type. For example:
0161: * <blockquote>
0162: * <pre>
0163: * int[] myIntegers = (int[]) myResources.getObject("intList");
0164: * </pre>
0165: * </blockquote>
0166: *
0167: * <P>
0168: * The Java Platform provides two subclasses of <code>ResourceBundle</code>,
0169: * <code>ListResourceBundle</code> and <code>PropertyResourceBundle</code>,
0170: * that provide a fairly simple way to create resources.
0171: * As you saw briefly in a previous example, <code>ListResourceBundle</code>
0172: * manages its resource as a list of key/value pairs.
0173: * <code>PropertyResourceBundle</code> uses a properties file to manage
0174: * its resources.
0175: *
0176: * <p>
0177: * If <code>ListResourceBundle</code> or <code>PropertyResourceBundle</code>
0178: * do not suit your needs, you can write your own <code>ResourceBundle</code>
0179: * subclass. Your subclasses must override two methods: <code>handleGetObject</code>
0180: * and <code>getKeys()</code>.
0181: *
0182: * <h4>ResourceBundle.Control</h4>
0183: *
0184: * The {@link ResourceBundle.Control} class provides information necessary
0185: * to perform the bundle loading process by the <code>getBundle</code>
0186: * factory methods that take a <code>ResourceBundle.Control</code>
0187: * instance. You can implement your own subclass in order to enable
0188: * non-standard resource bundle formats, change the search strategy, or
0189: * define caching parameters. Refer to the descriptions of the class and the
0190: * {@link #getBundle(String, Locale, ClassLoader, Control) getBundle}
0191: * factory method for details.
0192: *
0193: * <h4>Cache Management</h4>
0194: *
0195: * Resource bundle instances created by the <code>getBundle</code> factory
0196: * methods are cached by default, and the factory methods return the same
0197: * resource bundle instance multiple times if it has been
0198: * cached. <code>getBundle</code> clients may clear the cache, manage the
0199: * lifetime of cached resource bundle instances using time-to-live values,
0200: * or specify not to cache resource bundle instances. Refer to the
0201: * descriptions of the {@linkplain #getBundle(String, Locale, ClassLoader,
0202: * Control) <code>getBundle</code> factory method}, {@link
0203: * #clearCache(ClassLoader) clearCache}, {@link
0204: * Control#getTimeToLive(String, Locale)
0205: * ResourceBundle.Control.getTimeToLive}, and {@link
0206: * Control#needsReload(String, Locale, String, ClassLoader, ResourceBundle,
0207: * long) ResourceBundle.Control.needsReload} for details.
0208: *
0209: * <h4>Example</h4>
0210: *
0211: * The following is a very simple example of a <code>ResourceBundle</code>
0212: * subclass, <code>MyResources</code>, that manages two resources (for a larger number of
0213: * resources you would probably use a <code>Map</code>).
0214: * Notice that you don't need to supply a value if
0215: * a "parent-level" <code>ResourceBundle</code> handles the same
0216: * key with the same value (as for the okKey below).
0217: * <blockquote>
0218: * <pre>
0219: * // default (English language, United States)
0220: * public class MyResources extends ResourceBundle {
0221: * public Object handleGetObject(String key) {
0222: * if (key.equals("okKey")) return "Ok";
0223: * if (key.equals("cancelKey")) return "Cancel";
0224: * return null;
0225: * }
0226: *
0227: * public Enumeration<String> getKeys() {
0228: * return Collections.enumeration(keySet());
0229: * }
0230: *
0231: * // Overrides handleKeySet() so that the getKeys() implementation
0232: * // can rely on the keySet() value.
0233: * protected Set<String> handleKeySet() {
0234: * return new HashSet<String>(Arrays.asList("okKey", "cancelKey"));
0235: * }
0236: * }
0237: *
0238: * // German language
0239: * public class MyResources_de extends MyResources {
0240: * public Object handleGetObject(String key) {
0241: * // don't need okKey, since parent level handles it.
0242: * if (key.equals("cancelKey")) return "Abbrechen";
0243: * return null;
0244: * }
0245: *
0246: * protected Set<String> handleKeySet() {
0247: * return new HashSet<String>(Arrays.asList("cancelKey"));
0248: * }
0249: * }
0250: * </pre>
0251: * </blockquote>
0252: * You do not have to restrict yourself to using a single family of
0253: * <code>ResourceBundle</code>s. For example, you could have a set of bundles for
0254: * exception messages, <code>ExceptionResources</code>
0255: * (<code>ExceptionResources_fr</code>, <code>ExceptionResources_de</code>, ...),
0256: * and one for widgets, <code>WidgetResource</code> (<code>WidgetResources_fr</code>,
0257: * <code>WidgetResources_de</code>, ...); breaking up the resources however you like.
0258: *
0259: * @see ListResourceBundle
0260: * @see PropertyResourceBundle
0261: * @see MissingResourceException
0262: * @since JDK1.1
0263: */
0264: public abstract class ResourceBundle {
0265:
0266: /** initial size of the bundle cache */
0267: private static final int INITIAL_CACHE_SIZE = 32;
0268:
0269: /** constant indicating that no resource bundle exists */
0270: private static final ResourceBundle NONEXISTENT_BUNDLE = new ResourceBundle() {
0271: public Enumeration<String> getKeys() {
0272: return null;
0273: }
0274:
0275: protected Object handleGetObject(String key) {
0276: return null;
0277: }
0278:
0279: public String toString() {
0280: return "NONEXISTENT_BUNDLE";
0281: }
0282: };
0283:
0284: /**
0285: * The cache is a map from cache keys (with bundle base name, locale, and
0286: * class loader) to either a resource bundle or NONEXISTENT_BUNDLE wrapped by a
0287: * BundleReference.
0288: *
0289: * The cache is a ConcurrentMap, allowing the cache to be searched
0290: * concurrently by multiple threads. This will also allow the cache keys
0291: * to be reclaimed along with the ClassLoaders they reference.
0292: *
0293: * This variable would be better named "cache", but we keep the old
0294: * name for compatibility with some workarounds for bug 4212439.
0295: */
0296: private static final ConcurrentMap<CacheKey, BundleReference> cacheList = new ConcurrentHashMap<CacheKey, BundleReference>(
0297: INITIAL_CACHE_SIZE);
0298:
0299: /**
0300: * This ConcurrentMap is used to keep multiple threads from loading the
0301: * same bundle concurrently. The table entries are <CacheKey, Thread>
0302: * where CacheKey is the key for the bundle that is under construction
0303: * and Thread is the thread that is constructing the bundle.
0304: * This list is manipulated in findBundleInCache and putBundleInCache.
0305: */
0306: private static final ConcurrentMap<CacheKey, Thread> underConstruction = new ConcurrentHashMap<CacheKey, Thread>();
0307:
0308: /**
0309: * Queue for reference objects referring to class loaders or bundles.
0310: */
0311: private static final ReferenceQueue referenceQueue = new ReferenceQueue();
0312:
0313: /**
0314: * The parent bundle of this bundle.
0315: * The parent bundle is searched by {@link #getObject getObject}
0316: * when this bundle does not contain a particular resource.
0317: */
0318: protected ResourceBundle parent = null;
0319:
0320: /**
0321: * The locale for this bundle.
0322: */
0323: private Locale locale = null;
0324:
0325: /**
0326: * The base bundle name for this bundle.
0327: */
0328: private String name;
0329:
0330: /**
0331: * The flag indicating this bundle has expired in the cache.
0332: */
0333: private volatile boolean expired;
0334:
0335: /**
0336: * The back link to the cache key. null if this bundle isn't in
0337: * the cache (yet) or has expired.
0338: */
0339: private volatile CacheKey cacheKey;
0340:
0341: /**
0342: * A Set of the keys contained only in this ResourceBundle.
0343: */
0344: private volatile Set<String> keySet;
0345:
0346: /**
0347: * Sole constructor. (For invocation by subclass constructors, typically
0348: * implicit.)
0349: */
0350: public ResourceBundle() {
0351: }
0352:
0353: /**
0354: * Gets a string for the given key from this resource bundle or one of its parents.
0355: * Calling this method is equivalent to calling
0356: * <blockquote>
0357: * <code>(String) {@link #getObject(java.lang.String) getObject}(key)</code>.
0358: * </blockquote>
0359: *
0360: * @param key the key for the desired string
0361: * @exception NullPointerException if <code>key</code> is <code>null</code>
0362: * @exception MissingResourceException if no object for the given key can be found
0363: * @exception ClassCastException if the object found for the given key is not a string
0364: * @return the string for the given key
0365: */
0366: public final String getString(String key) {
0367: return (String) getObject(key);
0368: }
0369:
0370: /**
0371: * Gets a string array for the given key from this resource bundle or one of its parents.
0372: * Calling this method is equivalent to calling
0373: * <blockquote>
0374: * <code>(String[]) {@link #getObject(java.lang.String) getObject}(key)</code>.
0375: * </blockquote>
0376: *
0377: * @param key the key for the desired string array
0378: * @exception NullPointerException if <code>key</code> is <code>null</code>
0379: * @exception MissingResourceException if no object for the given key can be found
0380: * @exception ClassCastException if the object found for the given key is not a string array
0381: * @return the string array for the given key
0382: */
0383: public final String[] getStringArray(String key) {
0384: return (String[]) getObject(key);
0385: }
0386:
0387: /**
0388: * Gets an object for the given key from this resource bundle or one of its parents.
0389: * This method first tries to obtain the object from this resource bundle using
0390: * {@link #handleGetObject(java.lang.String) handleGetObject}.
0391: * If not successful, and the parent resource bundle is not null,
0392: * it calls the parent's <code>getObject</code> method.
0393: * If still not successful, it throws a MissingResourceException.
0394: *
0395: * @param key the key for the desired object
0396: * @exception NullPointerException if <code>key</code> is <code>null</code>
0397: * @exception MissingResourceException if no object for the given key can be found
0398: * @return the object for the given key
0399: */
0400: public final Object getObject(String key) {
0401: Object obj = handleGetObject(key);
0402: if (obj == null) {
0403: if (parent != null) {
0404: obj = parent.getObject(key);
0405: }
0406: if (obj == null)
0407: throw new MissingResourceException(
0408: "Can't find resource for bundle "
0409: + this .getClass().getName() + ", key "
0410: + key, this .getClass().getName(), key);
0411: }
0412: return obj;
0413: }
0414:
0415: /**
0416: * Returns the locale of this resource bundle. This method can be used after a
0417: * call to getBundle() to determine whether the resource bundle returned really
0418: * corresponds to the requested locale or is a fallback.
0419: *
0420: * @return the locale of this resource bundle
0421: */
0422: public Locale getLocale() {
0423: return locale;
0424: }
0425:
0426: /*
0427: * Automatic determination of the ClassLoader to be used to load
0428: * resources on behalf of the client. N.B. The client is getLoader's
0429: * caller's caller.
0430: */
0431: private static ClassLoader getLoader() {
0432: Class[] stack = getClassContext();
0433: /* Magic number 2 identifies our caller's caller */
0434: Class c = stack[2];
0435: ClassLoader cl = (c == null) ? null : c.getClassLoader();
0436: if (cl == null) {
0437: // When the caller's loader is the boot class loader, cl is null
0438: // here. In that case, ClassLoader.getSystemClassLoader() may
0439: // return the same class loader that the application is
0440: // using. We therefore use a wrapper ClassLoader to create a
0441: // separate scope for bundles loaded on behalf of the Java
0442: // runtime so that these bundles cannot be returned from the
0443: // cache to the application (5048280).
0444: cl = RBClassLoader.INSTANCE;
0445: }
0446: return cl;
0447: }
0448:
0449: private static native Class[] getClassContext();
0450:
0451: /**
0452: * A wrapper of ClassLoader.getSystemClassLoader().
0453: */
0454: private static class RBClassLoader extends ClassLoader {
0455: private static final RBClassLoader INSTANCE = AccessController
0456: .doPrivileged(new PrivilegedAction<RBClassLoader>() {
0457: public RBClassLoader run() {
0458: return new RBClassLoader();
0459: }
0460: });
0461: private static final ClassLoader loader = ClassLoader
0462: .getSystemClassLoader();
0463:
0464: private RBClassLoader() {
0465: }
0466:
0467: public Class<?> loadClass(String name)
0468: throws ClassNotFoundException {
0469: if (loader != null) {
0470: return loader.loadClass(name);
0471: }
0472: return Class.forName(name);
0473: }
0474:
0475: public URL getResource(String name) {
0476: if (loader != null) {
0477: return loader.getResource(name);
0478: }
0479: return ClassLoader.getSystemResource(name);
0480: }
0481:
0482: public InputStream getResourceAsStream(String name) {
0483: if (loader != null) {
0484: return loader.getResourceAsStream(name);
0485: }
0486: return ClassLoader.getSystemResourceAsStream(name);
0487: }
0488: }
0489:
0490: /**
0491: * Sets the parent bundle of this bundle.
0492: * The parent bundle is searched by {@link #getObject getObject}
0493: * when this bundle does not contain a particular resource.
0494: *
0495: * @param parent this bundle's parent bundle.
0496: */
0497: protected void setParent(ResourceBundle parent) {
0498: assert parent != NONEXISTENT_BUNDLE;
0499: this .parent = parent;
0500: }
0501:
0502: /**
0503: * Key used for cached resource bundles. The key checks the base
0504: * name, the locale, and the class loader to determine if the
0505: * resource is a match to the requested one. The loader may be
0506: * null, but the base name and the locale must have a non-null
0507: * value.
0508: */
0509: private static final class CacheKey implements Cloneable {
0510: // These three are the actual keys for lookup in Map.
0511: private String name;
0512: private Locale locale;
0513: private LoaderReference loaderRef;
0514:
0515: // bundle format which is necessary for calling
0516: // Control.needsReload().
0517: private String format;
0518:
0519: // These time values are in CacheKey so that NONEXISTENT_BUNDLE
0520: // doesn't need to be cloned for caching.
0521:
0522: // The time when the bundle has been loaded
0523: private volatile long loadTime;
0524:
0525: // The time when the bundle expires in the cache, or either
0526: // Control.TTL_DONT_CACHE or Control.TTL_NO_EXPIRATION_CONTROL.
0527: private volatile long expirationTime;
0528:
0529: // Placeholder for an error report by a Throwable
0530: private Throwable cause;
0531:
0532: // Hash code value cache to avoid recalculating the hash code
0533: // of this instance.
0534: private int hashCodeCache;
0535:
0536: CacheKey(String baseName, Locale locale, ClassLoader loader) {
0537: this .name = baseName;
0538: this .locale = locale;
0539: if (loader == null) {
0540: this .loaderRef = null;
0541: } else {
0542: loaderRef = new LoaderReference(loader, referenceQueue,
0543: this );
0544: }
0545: calculateHashCode();
0546: }
0547:
0548: String getName() {
0549: return name;
0550: }
0551:
0552: CacheKey setName(String baseName) {
0553: if (!this .name.equals(baseName)) {
0554: this .name = baseName;
0555: calculateHashCode();
0556: }
0557: return this ;
0558: }
0559:
0560: Locale getLocale() {
0561: return locale;
0562: }
0563:
0564: CacheKey setLocale(Locale locale) {
0565: if (!this .locale.equals(locale)) {
0566: this .locale = locale;
0567: calculateHashCode();
0568: }
0569: return this ;
0570: }
0571:
0572: ClassLoader getLoader() {
0573: return (loaderRef != null) ? loaderRef.get() : null;
0574: }
0575:
0576: public boolean equals(Object other) {
0577: if (this == other) {
0578: return true;
0579: }
0580: try {
0581: final CacheKey otherEntry = (CacheKey) other;
0582: //quick check to see if they are not equal
0583: if (hashCodeCache != otherEntry.hashCodeCache) {
0584: return false;
0585: }
0586: //are the names the same?
0587: if (!name.equals(otherEntry.name)) {
0588: return false;
0589: }
0590: // are the locales the same?
0591: if (!locale.equals(otherEntry.locale)) {
0592: return false;
0593: }
0594: //are refs (both non-null) or (both null)?
0595: if (loaderRef == null) {
0596: return otherEntry.loaderRef == null;
0597: }
0598: ClassLoader loader = loaderRef.get();
0599: return (otherEntry.loaderRef != null)
0600: // with a null reference we can no longer find
0601: // out which class loader was referenced; so
0602: // treat it as unequal
0603: && (loader != null)
0604: && (loader == otherEntry.loaderRef.get());
0605: } catch (NullPointerException e) {
0606: } catch (ClassCastException e) {
0607: }
0608: return false;
0609: }
0610:
0611: public int hashCode() {
0612: return hashCodeCache;
0613: }
0614:
0615: private void calculateHashCode() {
0616: hashCodeCache = name.hashCode() << 3;
0617: hashCodeCache ^= locale.hashCode();
0618: ClassLoader loader = getLoader();
0619: if (loader != null) {
0620: hashCodeCache ^= loader.hashCode();
0621: }
0622: }
0623:
0624: public Object clone() {
0625: try {
0626: CacheKey clone = (CacheKey) super .clone();
0627: if (loaderRef != null) {
0628: clone.loaderRef = new LoaderReference(loaderRef
0629: .get(), referenceQueue, clone);
0630: }
0631: // Clear the reference to a Throwable
0632: clone.cause = null;
0633: return clone;
0634: } catch (CloneNotSupportedException e) {
0635: //this should never happen
0636: throw new InternalError();
0637: }
0638: }
0639:
0640: String getFormat() {
0641: return format;
0642: }
0643:
0644: void setFormat(String format) {
0645: this .format = format;
0646: }
0647:
0648: private void setCause(Throwable cause) {
0649: if (this .cause == null) {
0650: this .cause = cause;
0651: } else {
0652: // Override the cause if the previous one is
0653: // ClassNotFoundException.
0654: if (this .cause instanceof ClassNotFoundException) {
0655: this .cause = cause;
0656: }
0657: }
0658: }
0659:
0660: private Throwable getCause() {
0661: return cause;
0662: }
0663:
0664: public String toString() {
0665: String l = locale.toString();
0666: if (l.length() == 0) {
0667: if (locale.getVariant().length() != 0) {
0668: l = "__" + locale.getVariant();
0669: } else {
0670: l = "\"\"";
0671: }
0672: }
0673: return "CacheKey[" + name + ", lc=" + l + ", ldr="
0674: + getLoader() + "(format=" + format + ")]";
0675: }
0676: }
0677:
0678: /**
0679: * The common interface to get a CacheKey in LoaderReference and
0680: * BundleReference.
0681: */
0682: private static interface CacheKeyReference {
0683: public CacheKey getCacheKey();
0684: }
0685:
0686: /**
0687: * References to class loaders are weak references, so that they can be
0688: * garbage collected when nobody else is using them. The ResourceBundle
0689: * class has no reason to keep class loaders alive.
0690: */
0691: private static final class LoaderReference extends
0692: WeakReference<ClassLoader> implements CacheKeyReference {
0693: private CacheKey cacheKey;
0694:
0695: LoaderReference(ClassLoader referent, ReferenceQueue q,
0696: CacheKey key) {
0697: super (referent, q);
0698: cacheKey = key;
0699: }
0700:
0701: public CacheKey getCacheKey() {
0702: return cacheKey;
0703: }
0704: }
0705:
0706: /**
0707: * References to bundles are soft references so that they can be garbage
0708: * collected when they have no hard references.
0709: */
0710: private static final class BundleReference extends
0711: SoftReference<ResourceBundle> implements CacheKeyReference {
0712: private CacheKey cacheKey;
0713:
0714: BundleReference(ResourceBundle referent, ReferenceQueue q,
0715: CacheKey key) {
0716: super (referent, q);
0717: cacheKey = key;
0718: }
0719:
0720: public CacheKey getCacheKey() {
0721: return cacheKey;
0722: }
0723: }
0724:
0725: /**
0726: * Gets a resource bundle using the specified base name, the default locale,
0727: * and the caller's class loader. Calling this method is equivalent to calling
0728: * <blockquote>
0729: * <code>getBundle(baseName, Locale.getDefault(), this.getClass().getClassLoader())</code>,
0730: * </blockquote>
0731: * except that <code>getClassLoader()</code> is run with the security
0732: * privileges of <code>ResourceBundle</code>.
0733: * See {@link #getBundle(String, Locale, ClassLoader) getBundle}
0734: * for a complete description of the search and instantiation strategy.
0735: *
0736: * @param baseName the base name of the resource bundle, a fully qualified class name
0737: * @exception java.lang.NullPointerException
0738: * if <code>baseName</code> is <code>null</code>
0739: * @exception MissingResourceException
0740: * if no resource bundle for the specified base name can be found
0741: * @return a resource bundle for the given base name and the default locale
0742: */
0743: public static final ResourceBundle getBundle(String baseName) {
0744: return getBundleImpl(baseName, Locale.getDefault(),
0745: /* must determine loader here, else we break stack invariant */
0746: getLoader(), Control.INSTANCE);
0747: }
0748:
0749: /**
0750: * Returns a resource bundle using the specified base name, the
0751: * default locale and the specified control. Calling this method
0752: * is equivalent to calling
0753: * <pre>
0754: * getBundle(baseName, Locale.getDefault(),
0755: * this.getClass().getClassLoader(), control),
0756: * </pre>
0757: * except that <code>getClassLoader()</code> is run with the security
0758: * privileges of <code>ResourceBundle</code>. See {@link
0759: * #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
0760: * complete description of the resource bundle loading process with a
0761: * <code>ResourceBundle.Control</code>.
0762: *
0763: * @param baseName
0764: * the base name of the resource bundle, a fully qualified class
0765: * name
0766: * @param control
0767: * the control which gives information for the resource bundle
0768: * loading process
0769: * @return a resource bundle for the given base name and the default
0770: * locale
0771: * @exception NullPointerException
0772: * if <code>baseName</code> or <code>control</code> is
0773: * <code>null</code>
0774: * @exception MissingResourceException
0775: * if no resource bundle for the specified base name can be found
0776: * @exception IllegalArgumentException
0777: * if the given <code>control</code> doesn't perform properly
0778: * (e.g., <code>control.getCandidateLocales</code> returns null.)
0779: * Note that validation of <code>control</code> is performed as
0780: * needed.
0781: * @since 1.6
0782: */
0783: public static final ResourceBundle getBundle(String baseName,
0784: Control control) {
0785: return getBundleImpl(baseName, Locale.getDefault(),
0786: /* must determine loader here, else we break stack invariant */
0787: getLoader(), control);
0788: }
0789:
0790: /**
0791: * Gets a resource bundle using the specified base name and locale,
0792: * and the caller's class loader. Calling this method is equivalent to calling
0793: * <blockquote>
0794: * <code>getBundle(baseName, locale, this.getClass().getClassLoader())</code>,
0795: * </blockquote>
0796: * except that <code>getClassLoader()</code> is run with the security
0797: * privileges of <code>ResourceBundle</code>.
0798: * See {@link #getBundle(String, Locale, ClassLoader) getBundle}
0799: * for a complete description of the search and instantiation strategy.
0800: *
0801: * @param baseName
0802: * the base name of the resource bundle, a fully qualified class name
0803: * @param locale
0804: * the locale for which a resource bundle is desired
0805: * @exception NullPointerException
0806: * if <code>baseName</code> or <code>locale</code> is <code>null</code>
0807: * @exception MissingResourceException
0808: * if no resource bundle for the specified base name can be found
0809: * @return a resource bundle for the given base name and locale
0810: */
0811: public static final ResourceBundle getBundle(String baseName,
0812: Locale locale) {
0813: return getBundleImpl(baseName, locale,
0814: /* must determine loader here, else we break stack invariant */
0815: getLoader(), Control.INSTANCE);
0816: }
0817:
0818: /**
0819: * Returns a resource bundle using the specified base name, target
0820: * locale and control, and the caller's class loader. Calling this
0821: * method is equivalent to calling
0822: * <pre>
0823: * getBundle(baseName, targetLocale, this.getClass().getClassLoader(),
0824: * control),
0825: * </pre>
0826: * except that <code>getClassLoader()</code> is run with the security
0827: * privileges of <code>ResourceBundle</code>. See {@link
0828: * #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
0829: * complete description of the resource bundle loading process with a
0830: * <code>ResourceBundle.Control</code>.
0831: *
0832: * @param baseName
0833: * the base name of the resource bundle, a fully qualified
0834: * class name
0835: * @param targetLocale
0836: * the locale for which a resource bundle is desired
0837: * @param control
0838: * the control which gives information for the resource
0839: * bundle loading process
0840: * @return a resource bundle for the given base name and a
0841: * <code>Locale</code> in <code>locales</code>
0842: * @exception NullPointerException
0843: * if <code>baseName</code>, <code>locales</code> or
0844: * <code>control</code> is <code>null</code>
0845: * @exception MissingResourceException
0846: * if no resource bundle for the specified base name in any
0847: * of the <code>locales</code> can be found.
0848: * @exception IllegalArgumentException
0849: * if the given <code>control</code> doesn't perform properly
0850: * (e.g., <code>control.getCandidateLocales</code> returns null.)
0851: * Note that validation of <code>control</code> is performed as
0852: * needed.
0853: * @since 1.6
0854: */
0855: public static final ResourceBundle getBundle(String baseName,
0856: Locale targetLocale, Control control) {
0857: return getBundleImpl(baseName, targetLocale,
0858: /* must determine loader here, else we break stack invariant */
0859: getLoader(), control);
0860: }
0861:
0862: /**
0863: * Gets a resource bundle using the specified base name, locale, and class loader.
0864: *
0865: * <p><a name="default_behavior"/>
0866: * Conceptually, <code>getBundle</code> uses the following strategy for locating and instantiating
0867: * resource bundles:
0868: * <p>
0869: * <code>getBundle</code> uses the base name, the specified locale, and the default
0870: * locale (obtained from {@link java.util.Locale#getDefault() Locale.getDefault})
0871: * to generate a sequence of <a name="candidates"><em>candidate bundle names</em></a>.
0872: * If the specified locale's language, country, and variant are all empty
0873: * strings, then the base name is the only candidate bundle name.
0874: * Otherwise, the following sequence is generated from the attribute
0875: * values of the specified locale (language1, country1, and variant1)
0876: * and of the default locale (language2, country2, and variant2):
0877: * <ul>
0878: * <li> baseName + "_" + language1 + "_" + country1 + "_" + variant1
0879: * <li> baseName + "_" + language1 + "_" + country1
0880: * <li> baseName + "_" + language1
0881: * <li> baseName + "_" + language2 + "_" + country2 + "_" + variant2
0882: * <li> baseName + "_" + language2 + "_" + country2
0883: * <li> baseName + "_" + language2
0884: * <li> baseName
0885: * </ul>
0886: * <p>
0887: * Candidate bundle names where the final component is an empty string are omitted.
0888: * For example, if country1 is an empty string, the second candidate bundle name is omitted.
0889: *
0890: * <p>
0891: * <code>getBundle</code> then iterates over the candidate bundle names to find the first
0892: * one for which it can <em>instantiate</em> an actual resource bundle. For each candidate
0893: * bundle name, it attempts to create a resource bundle:
0894: * <ul>
0895: * <li>
0896: * First, it attempts to load a class using the candidate bundle name.
0897: * If such a class can be found and loaded using the specified class loader, is assignment
0898: * compatible with ResourceBundle, is accessible from ResourceBundle, and can be instantiated,
0899: * <code>getBundle</code> creates a new instance of this class and uses it as the <em>result
0900: * resource bundle</em>.
0901: * <li>
0902: * Otherwise, <code>getBundle</code> attempts to locate a property resource file.
0903: * It generates a path name from the candidate bundle name by replacing all "." characters
0904: * with "/" and appending the string ".properties".
0905: * It attempts to find a "resource" with this name using
0906: * {@link java.lang.ClassLoader#getResource(java.lang.String) ClassLoader.getResource}.
0907: * (Note that a "resource" in the sense of <code>getResource</code> has nothing to do with
0908: * the contents of a resource bundle, it is just a container of data, such as a file.)
0909: * If it finds a "resource", it attempts to create a new
0910: * {@link PropertyResourceBundle} instance from its contents.
0911: * If successful, this instance becomes the <em>result resource bundle</em>.
0912: * </ul>
0913: *
0914: * <p>
0915: * If no result resource bundle has been found, a <code>MissingResourceException</code>
0916: * is thrown.
0917: *
0918: * <p><a name="parent_chain"/>
0919: * Once a result resource bundle has been found, its <em>parent chain</em> is instantiated.
0920: * <code>getBundle</code> iterates over the candidate bundle names that can be
0921: * obtained by successively removing variant, country, and language
0922: * (each time with the preceding "_") from the bundle name of the result resource bundle.
0923: * As above, candidate bundle names where the final component is an empty string are omitted.
0924: * With each of the candidate bundle names it attempts to instantiate a resource bundle, as
0925: * described above.
0926: * Whenever it succeeds, it calls the previously instantiated resource
0927: * bundle's {@link #setParent(java.util.ResourceBundle) setParent} method
0928: * with the new resource bundle, unless the previously instantiated resource
0929: * bundle already has a non-null parent.
0930: *
0931: * <p>
0932: * <code>getBundle</code> caches instantiated resource bundles and
0933: * may return the same resource bundle instance multiple
0934: * times.
0935: *
0936: * <p>
0937: * The <code>baseName</code> argument should be a fully qualified class name. However, for
0938: * compatibility with earlier versions, Sun's Java SE Runtime Environments do not verify this,
0939: * and so it is possible to access <code>PropertyResourceBundle</code>s by specifying a
0940: * path name (using "/") instead of a fully qualified class name (using ".").
0941: *
0942: * <p><a name="default_behavior_example"/>
0943: * <strong>Example:</strong><br>The following class and property files are provided:
0944: * <pre>
0945: * MyResources.class
0946: * MyResources.properties
0947: * MyResources_fr.properties
0948: * MyResources_fr_CH.class
0949: * MyResources_fr_CH.properties
0950: * MyResources_en.properties
0951: * MyResources_es_ES.class
0952: * </pre>
0953: * The contents of all files are valid (that is, public non-abstract subclasses of <code>ResourceBundle</code> for
0954: * the ".class" files, syntactically correct ".properties" files).
0955: * The default locale is <code>Locale("en", "GB")</code>.
0956: * <p>
0957: * Calling <code>getBundle</code> with the shown locale argument values instantiates
0958: * resource bundles from the following sources:
0959: * <ul>
0960: * <li>Locale("fr", "CH"): result MyResources_fr_CH.class, parent MyResources_fr.properties, parent MyResources.class
0961: * <li>Locale("fr", "FR"): result MyResources_fr.properties, parent MyResources.class
0962: * <li>Locale("de", "DE"): result MyResources_en.properties, parent MyResources.class
0963: * <li>Locale("en", "US"): result MyResources_en.properties, parent MyResources.class
0964: * <li>Locale("es", "ES"): result MyResources_es_ES.class, parent MyResources.class
0965: * </ul>
0966: * <p>The file MyResources_fr_CH.properties is never used because it is hidden by
0967: * MyResources_fr_CH.class. Likewise, MyResources.properties is also hidden by
0968: * MyResources.class.
0969: *
0970: * @param baseName the base name of the resource bundle, a fully qualified class name
0971: * @param locale the locale for which a resource bundle is desired
0972: * @param loader the class loader from which to load the resource bundle
0973: * @return a resource bundle for the given base name and locale
0974: * @exception java.lang.NullPointerException
0975: * if <code>baseName</code>, <code>locale</code>, or <code>loader</code> is <code>null</code>
0976: * @exception MissingResourceException
0977: * if no resource bundle for the specified base name can be found
0978: * @since 1.2
0979: */
0980: public static ResourceBundle getBundle(String baseName,
0981: Locale locale, ClassLoader loader) {
0982: if (loader == null) {
0983: throw new NullPointerException();
0984: }
0985: return getBundleImpl(baseName, locale, loader, Control.INSTANCE);
0986: }
0987:
0988: /**
0989: * Returns a resource bundle using the specified base name, target
0990: * locale, class loader and control. Unlike the {@linkplain
0991: * #getBundle(String, Locale, ClassLoader) <code>getBundle</code>
0992: * factory methods with no <code>control</code> argument}, the given
0993: * <code>control</code> specifies how to locate and instantiate resource
0994: * bundles. Conceptually, the bundle loading process with the given
0995: * <code>control</code> is performed in the following steps.
0996: *
0997: * <p>
0998: * <ol>
0999: * <li>This factory method looks up the resource bundle in the cache for
1000: * the specified <code>baseName</code>, <code>targetLocale</code> and
1001: * <code>loader</code>. If the requested resource bundle instance is
1002: * found in the cache and the time-to-live periods of the instance and
1003: * all of its parent instances have not expired, the instance is returned
1004: * to the caller. Otherwise, this factory method proceeds with the
1005: * loading process below.</li>
1006: *
1007: * <li>The {@link ResourceBundle.Control#getFormats(String)
1008: * control.getFormats} method is called to get resource bundle formats
1009: * to produce bundle or resource names. The strings
1010: * <code>"java.class"</code> and <code>"java.properties"</code>
1011: * designate class-based and {@linkplain PropertyResourceBundle
1012: * property}-based resource bundles, respectively. Other strings
1013: * starting with <code>"java."</code> are reserved for future extensions
1014: * and must not be used for application-defined formats. Other strings
1015: * designate application-defined formats.</li>
1016: *
1017: * <li>The {@link ResourceBundle.Control#getCandidateLocales(String,
1018: * Locale) control.getCandidateLocales} method is called with the target
1019: * locale to get a list of <em>candidate <code>Locale</code>s</em> for
1020: * which resource bundles are searched.</li>
1021: *
1022: * <li>The {@link ResourceBundle.Control#newBundle(String, Locale,
1023: * String, ClassLoader, boolean) control.newBundle} method is called to
1024: * instantiate a <code>ResourceBundle</code> for the base bundle name, a
1025: * candidate locale, and a format. (Refer to the note on the cache
1026: * lookup below.) This step is iterated over all combinations of the
1027: * candidate locales and formats until the <code>newBundle</code> method
1028: * returns a <code>ResourceBundle</code> instance or the iteration has
1029: * used up all the combinations. For example, if the candidate locales
1030: * are <code>Locale("de", "DE")</code>, <code>Locale("de")</code> and
1031: * <code>Locale("")</code> and the formats are <code>"java.class"</code>
1032: * and <code>"java.properties"</code>, then the following is the
1033: * sequence of locale-format combinations to be used to call
1034: * <code>control.newBundle</code>.
1035: *
1036: * <table style="width: 50%; text-align: left; margin-left: 40px;"
1037: * border="0" cellpadding="2" cellspacing="2">
1038: * <tbody><code>
1039: * <tr>
1040: * <td
1041: * style="vertical-align: top; text-align: left; font-weight: bold; width: 50%;">Locale<br>
1042: * </td>
1043: * <td
1044: * style="vertical-align: top; text-align: left; font-weight: bold; width: 50%;">format<br>
1045: * </td>
1046: * </tr>
1047: * <tr>
1048: * <td style="vertical-align: top; width: 50%;">Locale("de", "DE")<br>
1049: * </td>
1050: * <td style="vertical-align: top; width: 50%;">java.class<br>
1051: * </td>
1052: * </tr>
1053: * <tr>
1054: * <td style="vertical-align: top; width: 50%;">Locale("de", "DE")</td>
1055: * <td style="vertical-align: top; width: 50%;">java.properties<br>
1056: * </td>
1057: * </tr>
1058: * <tr>
1059: * <td style="vertical-align: top; width: 50%;">Locale("de")</td>
1060: * <td style="vertical-align: top; width: 50%;">java.class</td>
1061: * </tr>
1062: * <tr>
1063: * <td style="vertical-align: top; width: 50%;">Locale("de")</td>
1064: * <td style="vertical-align: top; width: 50%;">java.properties</td>
1065: * </tr>
1066: * <tr>
1067: * <td style="vertical-align: top; width: 50%;">Locale("")<br>
1068: * </td>
1069: * <td style="vertical-align: top; width: 50%;">java.class</td>
1070: * </tr>
1071: * <tr>
1072: * <td style="vertical-align: top; width: 50%;">Locale("")</td>
1073: * <td style="vertical-align: top; width: 50%;">java.properties</td>
1074: * </tr>
1075: * </code></tbody>
1076: * </table>
1077: * </li>
1078: *
1079: * <li>If the previous step has found no resource bundle, proceed to
1080: * Step 6. If a bundle has been found that is a base bundle (a bundle
1081: * for <code>Locale("")</code>), and the candidate locale list only contained
1082: * <code>Locale("")</code>, return the bundle to the caller. If a bundle
1083: * has been found that is a base bundle, but the candidate locale list
1084: * contained locales other than Locale(""), put the bundle on hold and
1085: * proceed to Step 6. If a bundle has been found that is not a base
1086: * bundle, proceed to Step 7.</li>
1087: *
1088: * <li>The {@link ResourceBundle.Control#getFallbackLocale(String,
1089: * Locale) control.getFallbackLocale} method is called to get a fallback
1090: * locale (alternative to the current target locale) to try further
1091: * finding a resource bundle. If the method returns a non-null locale,
1092: * it becomes the next target locale and the loading process starts over
1093: * from Step 3. Otherwise, if a base bundle was found and put on hold in
1094: * a previous Step 5, it is returned to the caller now. Otherwise, a
1095: * MissingResourceException is thrown.</li>
1096: *
1097: * <li>At this point, we have found a resource bundle that's not the
1098: * base bundle. If this bundle set its parent during its instantiation,
1099: * it is returned to the caller. Otherwise, its <a
1100: * href="./ResourceBundle.html#parent_chain">parent chain</a> is
1101: * instantiated based on the list of candidate locales from which it was
1102: * found. Finally, the bundle is returned to the caller.</li>
1103: *
1104: *
1105: * </ol>
1106: *
1107: * <p>During the resource bundle loading process above, this factory
1108: * method looks up the cache before calling the {@link
1109: * Control#newBundle(String, Locale, String, ClassLoader, boolean)
1110: * control.newBundle} method. If the time-to-live period of the
1111: * resource bundle found in the cache has expired, the factory method
1112: * calls the {@link ResourceBundle.Control#needsReload(String, Locale,
1113: * String, ClassLoader, ResourceBundle, long) control.needsReload}
1114: * method to determine whether the resource bundle needs to be reloaded.
1115: * If reloading is required, the factory method calls
1116: * <code>control.newBundle</code> to reload the resource bundle. If
1117: * <code>control.newBundle</code> returns <code>null</code>, the factory
1118: * method puts a dummy resource bundle in the cache as a mark of
1119: * nonexistent resource bundles in order to avoid lookup overhead for
1120: * subsequent requests. Such dummy resource bundles are under the same
1121: * expiration control as specified by <code>control</code>.
1122: *
1123: * <p>All resource bundles loaded are cached by default. Refer to
1124: * {@link Control#getTimeToLive(String,Locale)
1125: * control.getTimeToLive} for details.
1126: *
1127: *
1128: * <p>The following is an example of the bundle loading process with the
1129: * default <code>ResourceBundle.Control</code> implementation.
1130: *
1131: * <p>Conditions:
1132: * <ul>
1133: * <li>Base bundle name: <code>foo.bar.Messages</code>
1134: * <li>Requested <code>Locale</code>: {@link Locale#ITALY}</li>
1135: * <li>Default <code>Locale</code>: {@link Locale#FRENCH}</li>
1136: * <li>Available resource bundles:
1137: * <code>foo/bar/Messages_fr.properties</code> and
1138: * <code>foo/bar/Messages.properties</code></li>
1139: *
1140: * </ul>
1141: *
1142: * <p>First, <code>getBundle</code> tries loading a resource bundle in
1143: * the following sequence.
1144: *
1145: * <ul>
1146: * <li>class <code>foo.bar.Messages_it_IT</code>
1147: * <li>file <code>foo/bar/Messages_it_IT.properties</code>
1148: * <li>class <code>foo.bar.Messages_it</code></li>
1149: * <li>file <code>foo/bar/Messages_it.properties</code></li>
1150: * <li>class <code>foo.bar.Messages</code></li>
1151: * <li>file <code>foo/bar/Messages.properties</code></li>
1152: * </ul>
1153: *
1154: * <p>At this point, <code>getBundle</code> finds
1155: * <code>foo/bar/Messages.properties</code>, which is put on hold
1156: * because it's the base bundle. <code>getBundle</code> calls {@link
1157: * Control#getFallbackLocale(String, Locale)
1158: * control.getFallbackLocale("foo.bar.Messages", Locale.ITALY)} which
1159: * returns <code>Locale.FRENCH</code>. Next, <code>getBundle</code>
1160: * tries loading a bundle in the following sequence.
1161: *
1162: * <ul>
1163: * <li>class <code>foo.bar.Messages_fr</code></li>
1164: * <li>file <code>foo/bar/Messages_fr.properties</code></li>
1165: * <li>class <code>foo.bar.Messages</code></li>
1166: * <li>file <code>foo/bar/Messages.properties</code></li>
1167: * </ul>
1168: *
1169: * <p><code>getBundle</code> finds
1170: * <code>foo/bar/Messages_fr.properties</code> and creates a
1171: * <code>ResourceBundle</code> instance. Then, <code>getBundle</code>
1172: * sets up its parent chain from the list of the candiate locales. Only
1173: * <code>foo/bar/Messages.properties</code> is found in the list and
1174: * <code>getBundle</code> creates a <code>ResourceBundle</code> instance
1175: * that becomes the parent of the instance for
1176: * <code>foo/bar/Messages_fr.properties</code>.
1177: *
1178: * @param baseName
1179: * the base name of the resource bundle, a fully qualified
1180: * class name
1181: * @param targetLocale
1182: * the locale for which a resource bundle is desired
1183: * @param loader
1184: * the class loader from which to load the resource bundle
1185: * @param control
1186: * the control which gives information for the resource
1187: * bundle loading process
1188: * @return a resource bundle for the given base name and locale
1189: * @exception NullPointerException
1190: * if <code>baseName</code>, <code>targetLocale</code>,
1191: * <code>loader</code>, or <code>control</code> is
1192: * <code>null</code>
1193: * @exception MissingResourceException
1194: * if no resource bundle for the specified base name can be found
1195: * @exception IllegalArgumentException
1196: * if the given <code>control</code> doesn't perform properly
1197: * (e.g., <code>control.getCandidateLocales</code> returns null.)
1198: * Note that validation of <code>control</code> is performed as
1199: * needed.
1200: * @since 1.6
1201: */
1202: public static ResourceBundle getBundle(String baseName,
1203: Locale targetLocale, ClassLoader loader, Control control) {
1204: if (loader == null || control == null) {
1205: throw new NullPointerException();
1206: }
1207: return getBundleImpl(baseName, targetLocale, loader, control);
1208: }
1209:
1210: private static ResourceBundle getBundleImpl(String baseName,
1211: Locale locale, ClassLoader loader, Control control) {
1212: if (locale == null || control == null) {
1213: throw new NullPointerException();
1214: }
1215:
1216: // We create a CacheKey here for use by this call. The base
1217: // name and loader will never change during the bundle loading
1218: // process. We have to make sure that the locale is set before
1219: // using it as a cache key.
1220: CacheKey cacheKey = new CacheKey(baseName, locale, loader);
1221: ResourceBundle bundle = null;
1222:
1223: // Quick lookup of the cache.
1224: BundleReference bundleRef = cacheList.get(cacheKey);
1225: if (bundleRef != null) {
1226: bundle = bundleRef.get();
1227: bundleRef = null;
1228: }
1229:
1230: // If this bundle and all of its parents are valid (not expired),
1231: // then return this bundle. If any of the bundles is expired, we
1232: // don't call control.needsReload here but instead drop into the
1233: // complete loading process below.
1234: if (isValidBundle(bundle) && hasValidParentChain(bundle)) {
1235: return bundle;
1236: }
1237:
1238: // No valid bundle was found in the cache, so we need to load the
1239: // resource bundle and its parents.
1240:
1241: boolean isKnownControl = (control == Control.INSTANCE)
1242: || (control instanceof SingleFormatControl);
1243: List<String> formats = control.getFormats(baseName);
1244: if (!isKnownControl && !checkList(formats)) {
1245: throw new IllegalArgumentException(
1246: "Invalid Control: getFormats");
1247: }
1248:
1249: ResourceBundle baseBundle = null;
1250: for (Locale targetLocale = locale; targetLocale != null; targetLocale = control
1251: .getFallbackLocale(baseName, targetLocale)) {
1252: List<Locale> candidateLocales = control
1253: .getCandidateLocales(baseName, targetLocale);
1254: if (!isKnownControl && !checkList(candidateLocales)) {
1255: throw new IllegalArgumentException(
1256: "Invalid Control: getCandidateLocales");
1257: }
1258:
1259: bundle = findBundle(cacheKey, candidateLocales, formats, 0,
1260: control, baseBundle);
1261:
1262: // If the loaded bundle is the base bundle and exactly for the
1263: // requested locale or the only candidate locale, then take the
1264: // bundle as the resulting one. If the loaded bundle is the base
1265: // bundle, it's put on hold until we finish processing all
1266: // fallback locales.
1267: if (isValidBundle(bundle)) {
1268: boolean isBaseBundle = Locale.ROOT
1269: .equals(bundle.locale);
1270: if (!isBaseBundle
1271: || bundle.locale.equals(locale)
1272: || (candidateLocales.size() == 1 && bundle.locale
1273: .equals(candidateLocales.get(0)))) {
1274: break;
1275: }
1276:
1277: // If the base bundle has been loaded, keep the reference in
1278: // baseBundle so that we can avoid any redundant loading in case
1279: // the control specify not to cache bundles.
1280: if (isBaseBundle && baseBundle == null) {
1281: baseBundle = bundle;
1282: }
1283: }
1284: }
1285:
1286: if (bundle == null) {
1287: if (baseBundle == null) {
1288: throwMissingResourceException(baseName, locale,
1289: cacheKey.getCause());
1290: }
1291: bundle = baseBundle;
1292: }
1293:
1294: return bundle;
1295: }
1296:
1297: /**
1298: * Checks if the given <code>List</code> is not null, not empty,
1299: * not having null in its elements.
1300: */
1301: private static final boolean checkList(List a) {
1302: boolean valid = (a != null && a.size() != 0);
1303: if (valid) {
1304: int size = a.size();
1305: for (int i = 0; valid && i < size; i++) {
1306: valid = (a.get(i) != null);
1307: }
1308: }
1309: return valid;
1310: }
1311:
1312: private static final ResourceBundle findBundle(CacheKey cacheKey,
1313: List<Locale> candidateLocales, List<String> formats,
1314: int index, Control control, ResourceBundle baseBundle) {
1315: Locale targetLocale = candidateLocales.get(index);
1316: ResourceBundle parent = null;
1317: if (index != candidateLocales.size() - 1) {
1318: parent = findBundle(cacheKey, candidateLocales, formats,
1319: index + 1, control, baseBundle);
1320: } else if (baseBundle != null
1321: && Locale.ROOT.equals(targetLocale)) {
1322: return baseBundle;
1323: }
1324:
1325: // Before we do the real loading work, see whether we need to
1326: // do some housekeeping: If references to class loaders or
1327: // resource bundles have been nulled out, remove all related
1328: // information from the cache.
1329: Object ref;
1330: while ((ref = referenceQueue.poll()) != null) {
1331: cacheList.remove(((CacheKeyReference) ref).getCacheKey());
1332: }
1333:
1334: // flag indicating the resource bundle has expired in the cache
1335: boolean expiredBundle = false;
1336:
1337: // First, look up the cache to see if it's in the cache, without
1338: // declaring beginLoading.
1339: cacheKey.setLocale(targetLocale);
1340: ResourceBundle bundle = findBundleInCache(cacheKey, control);
1341: if (isValidBundle(bundle)) {
1342: expiredBundle = bundle.expired;
1343: if (!expiredBundle) {
1344: // If its parent is the one asked for by the candidate
1345: // locales (the runtime lookup path), we can take the cached
1346: // one. (If it's not identical, then we'd have to check the
1347: // parent's parents to be consistent with what's been
1348: // requested.)
1349: if (bundle.parent == parent) {
1350: return bundle;
1351: }
1352: // Otherwise, remove the cached one since we can't keep
1353: // the same bundles having different parents.
1354: BundleReference bundleRef = cacheList.get(cacheKey);
1355: if (bundleRef != null && bundleRef.get() == bundle) {
1356: cacheList.remove(cacheKey, bundleRef);
1357: }
1358: }
1359: }
1360:
1361: if (bundle != NONEXISTENT_BUNDLE) {
1362: CacheKey constKey = (CacheKey) cacheKey.clone();
1363:
1364: try {
1365: // Try declaring loading. If beginLoading() returns true,
1366: // then we can proceed. Otherwise, we need to take a look
1367: // at the cache again to see if someone else has loaded
1368: // the bundle and put it in the cache while we've been
1369: // waiting for other loading work to complete.
1370: while (!beginLoading(constKey)) {
1371: bundle = findBundleInCache(cacheKey, control);
1372: if (bundle == null) {
1373: continue;
1374: }
1375: if (bundle == NONEXISTENT_BUNDLE) {
1376: // If the bundle is NONEXISTENT_BUNDLE, the bundle doesn't exist.
1377: return parent;
1378: }
1379: expiredBundle = bundle.expired;
1380: if (!expiredBundle) {
1381: if (bundle.parent == parent) {
1382: return bundle;
1383: }
1384: BundleReference bundleRef = cacheList
1385: .get(cacheKey);
1386: if (bundleRef != null
1387: && bundleRef.get() == bundle) {
1388: cacheList.remove(cacheKey, bundleRef);
1389: }
1390: }
1391: }
1392:
1393: try {
1394: bundle = loadBundle(cacheKey, formats, control,
1395: expiredBundle);
1396: if (bundle != null) {
1397: if (bundle.parent == null) {
1398: bundle.setParent(parent);
1399: }
1400: bundle.locale = targetLocale;
1401: bundle = putBundleInCache(cacheKey, bundle,
1402: control);
1403: return bundle;
1404: }
1405:
1406: // Put NONEXISTENT_BUNDLE in the cache as a mark that there's no bundle
1407: // instance for the locale.
1408: putBundleInCache(cacheKey, NONEXISTENT_BUNDLE,
1409: control);
1410: } finally {
1411: endLoading(constKey);
1412: }
1413: } finally {
1414: if (constKey.getCause() instanceof InterruptedException) {
1415: Thread.currentThread().interrupt();
1416: }
1417: }
1418: }
1419: assert underConstruction.get(cacheKey) != Thread
1420: .currentThread();
1421: return parent;
1422: }
1423:
1424: private static final ResourceBundle loadBundle(CacheKey cacheKey,
1425: List<String> formats, Control control, boolean reload) {
1426: assert underConstruction.get(cacheKey) == Thread
1427: .currentThread();
1428:
1429: // Here we actually load the bundle in the order of formats
1430: // specified by the getFormats() value.
1431: Locale targetLocale = cacheKey.getLocale();
1432:
1433: ResourceBundle bundle = null;
1434: int size = formats.size();
1435: for (int i = 0; i < size; i++) {
1436: String format = formats.get(i);
1437: try {
1438: bundle = control.newBundle(cacheKey.getName(),
1439: targetLocale, format, cacheKey.getLoader(),
1440: reload);
1441: } catch (LinkageError error) {
1442: // We need to handle the LinkageError case due to
1443: // inconsistent case-sensitivity in ClassLoader.
1444: // See 6572242 for details.
1445: cacheKey.setCause(error);
1446: } catch (Exception cause) {
1447: cacheKey.setCause(cause);
1448: }
1449: if (bundle != null) {
1450: // Set the format in the cache key so that it can be
1451: // used when calling needsReload later.
1452: cacheKey.setFormat(format);
1453: bundle.name = cacheKey.getName();
1454: bundle.locale = targetLocale;
1455: // Bundle provider might reuse instances. So we should make
1456: // sure to clear the expired flag here.
1457: bundle.expired = false;
1458: break;
1459: }
1460: }
1461: assert underConstruction.get(cacheKey) == Thread
1462: .currentThread();
1463:
1464: return bundle;
1465: }
1466:
1467: private static final boolean isValidBundle(ResourceBundle bundle) {
1468: return bundle != null && bundle != NONEXISTENT_BUNDLE;
1469: }
1470:
1471: /**
1472: * Determines whether any of resource bundles in the parent chain,
1473: * including the leaf, have expired.
1474: */
1475: private static final boolean hasValidParentChain(
1476: ResourceBundle bundle) {
1477: long now = System.currentTimeMillis();
1478: while (bundle != null) {
1479: if (bundle.expired) {
1480: return false;
1481: }
1482: CacheKey key = bundle.cacheKey;
1483: if (key != null) {
1484: long expirationTime = key.expirationTime;
1485: if (expirationTime >= 0 && expirationTime <= now) {
1486: return false;
1487: }
1488: }
1489: bundle = bundle.parent;
1490: }
1491: return true;
1492: }
1493:
1494: /**
1495: * Declares the beginning of actual resource bundle loading. This method
1496: * returns true if the declaration is successful and the current thread has
1497: * been put in underConstruction. If someone else has already begun
1498: * loading, this method waits until that loading work is complete and
1499: * returns false.
1500: */
1501: private static final boolean beginLoading(CacheKey constKey) {
1502: Thread me = Thread.currentThread();
1503: Thread worker;
1504: // We need to declare by putting the current Thread (me) to
1505: // underConstruction that we are working on loading the specified
1506: // resource bundle. If we are already working the loading, it means
1507: // that the resource loading requires a recursive call. In that case,
1508: // we have to proceed. (4300693)
1509: if (((worker = underConstruction.putIfAbsent(constKey, me)) == null)
1510: || worker == me) {
1511: return true;
1512: }
1513:
1514: // If someone else is working on the loading, wait until
1515: // the Thread finishes the bundle loading.
1516: synchronized (worker) {
1517: while (underConstruction.get(constKey) == worker) {
1518: try {
1519: worker.wait();
1520: } catch (InterruptedException e) {
1521: // record the interruption
1522: constKey.setCause(e);
1523: }
1524: }
1525: }
1526: return false;
1527: }
1528:
1529: /**
1530: * Declares the end of the bundle loading. This method calls notifyAll
1531: * for those who are waiting for this completion.
1532: */
1533: private static final void endLoading(CacheKey constKey) {
1534: // Remove this Thread from the underConstruction map and wake up
1535: // those who have been waiting for me to complete this bundle
1536: // loading.
1537: Thread me = Thread.currentThread();
1538: assert (underConstruction.get(constKey) == me);
1539: underConstruction.remove(constKey);
1540: synchronized (me) {
1541: me.notifyAll();
1542: }
1543: }
1544:
1545: /**
1546: * Throw a MissingResourceException with proper message
1547: */
1548: private static final void throwMissingResourceException(
1549: String baseName, Locale locale, Throwable cause) {
1550: // If the cause is a MissingResourceException, avoid creating
1551: // a long chain. (6355009)
1552: if (cause instanceof MissingResourceException) {
1553: cause = null;
1554: }
1555: throw new MissingResourceException(
1556: "Can't find bundle for base name " + baseName
1557: + ", locale " + locale,
1558: baseName + "_" + locale, // className
1559: "", // key
1560: cause);
1561: }
1562:
1563: /**
1564: * Finds a bundle in the cache. Any expired bundles are marked as
1565: * `expired' and removed from the cache upon return.
1566: *
1567: * @param cacheKey the key to look up the cache
1568: * @param control the Control to be used for the expiration control
1569: * @return the cached bundle, or null if the bundle is not found in the
1570: * cache or its parent has expired. <code>bundle.expire</code> is true
1571: * upon return if the bundle in the cache has expired.
1572: */
1573: private static final ResourceBundle findBundleInCache(
1574: CacheKey cacheKey, Control control) {
1575: BundleReference bundleRef = cacheList.get(cacheKey);
1576: if (bundleRef == null) {
1577: return null;
1578: }
1579: ResourceBundle bundle = bundleRef.get();
1580: if (bundle == null) {
1581: return null;
1582: }
1583: ResourceBundle p = bundle.parent;
1584: assert p != NONEXISTENT_BUNDLE;
1585: // If the parent has expired, then this one must also expire. We
1586: // check only the immediate parent because the actual loading is
1587: // done from the root (base) to leaf (child) and the purpose of
1588: // checking is to propagate expiration towards the leaf. For
1589: // example, if the requested locale is ja_JP_JP and there are
1590: // bundles for all of the candidates in the cache, we have a list,
1591: //
1592: // base <- ja <- ja_JP <- ja_JP_JP
1593: //
1594: // If ja has expired, then it will reload ja and the list becomes a
1595: // tree.
1596: //
1597: // base <- ja (new)
1598: // " <- ja (expired) <- ja_JP <- ja_JP_JP
1599: //
1600: // When looking up ja_JP in the cache, it finds ja_JP in the cache
1601: // which references to the expired ja. Then, ja_JP is marked as
1602: // expired and removed from the cache. This will be propagated to
1603: // ja_JP_JP.
1604: //
1605: // Now, it's possible, for example, that while loading new ja_JP,
1606: // someone else has started loading the same bundle and finds the
1607: // base bundle has expired. Then, what we get from the first
1608: // getBundle call includes the expired base bundle. However, if
1609: // someone else didn't start its loading, we wouldn't know if the
1610: // base bundle has expired at the end of the loading process. The
1611: // expiration control doesn't guarantee that the returned bundle and
1612: // its parents haven't expired.
1613: //
1614: // We could check the entire parent chain to see if there's any in
1615: // the chain that has expired. But this process may never end. An
1616: // extreme case would be that getTimeToLive returns 0 and
1617: // needsReload always returns true.
1618: if (p != null && p.expired) {
1619: assert bundle != NONEXISTENT_BUNDLE;
1620: bundle.expired = true;
1621: bundle.cacheKey = null;
1622: cacheList.remove(cacheKey, bundleRef);
1623: bundle = null;
1624: } else {
1625: CacheKey key = bundleRef.getCacheKey();
1626: long expirationTime = key.expirationTime;
1627: if (!bundle.expired && expirationTime >= 0
1628: && expirationTime <= System.currentTimeMillis()) {
1629: // its TTL period has expired.
1630: if (bundle != NONEXISTENT_BUNDLE) {
1631: // Synchronize here to call needsReload to avoid
1632: // redundant concurrent calls for the same bundle.
1633: synchronized (bundle) {
1634: expirationTime = key.expirationTime;
1635: if (!bundle.expired
1636: && expirationTime >= 0
1637: && expirationTime <= System
1638: .currentTimeMillis()) {
1639: try {
1640: bundle.expired = control.needsReload(
1641: key.getName(), key.getLocale(),
1642: key.getFormat(), key
1643: .getLoader(), bundle,
1644: key.loadTime);
1645: } catch (Exception e) {
1646: cacheKey.setCause(e);
1647: }
1648: if (bundle.expired) {
1649: // If the bundle needs to be reloaded, then
1650: // remove the bundle from the cache, but
1651: // return the bundle with the expired flag
1652: // on.
1653: bundle.cacheKey = null;
1654: cacheList.remove(cacheKey, bundleRef);
1655: } else {
1656: // Update the expiration control info. and reuse
1657: // the same bundle instance
1658: setExpirationTime(key, control);
1659: }
1660: }
1661: }
1662: } else {
1663: // We just remove NONEXISTENT_BUNDLE from the cache.
1664: cacheList.remove(cacheKey, bundleRef);
1665: bundle = null;
1666: }
1667: }
1668: }
1669: return bundle;
1670: }
1671:
1672: /**
1673: * Put a new bundle in the cache.
1674: *
1675: * @param cacheKey the key for the resource bundle
1676: * @param bundle the resource bundle to be put in the cache
1677: * @return the ResourceBundle for the cacheKey; if someone has put
1678: * the bundle before this call, the one found in the cache is
1679: * returned.
1680: */
1681: private static final ResourceBundle putBundleInCache(
1682: CacheKey cacheKey, ResourceBundle bundle, Control control) {
1683: setExpirationTime(cacheKey, control);
1684: if (cacheKey.expirationTime != Control.TTL_DONT_CACHE) {
1685: CacheKey key = (CacheKey) cacheKey.clone();
1686: BundleReference bundleRef = new BundleReference(bundle,
1687: referenceQueue, key);
1688: bundle.cacheKey = key;
1689:
1690: // Put the bundle in the cache if it's not been in the cache.
1691: BundleReference result = cacheList.putIfAbsent(key,
1692: bundleRef);
1693:
1694: // If someone else has put the same bundle in the cache before
1695: // us and it has not expired, we should use the one in the cache.
1696: if (result != null) {
1697: ResourceBundle rb = result.get();
1698: if (rb != null && !rb.expired) {
1699: // Clear the back link to the cache key
1700: bundle.cacheKey = null;
1701: bundle = rb;
1702: // Clear the reference in the BundleReference so that
1703: // it won't be enqueued.
1704: bundleRef.clear();
1705: } else {
1706: // Replace the invalid (garbage collected or expired)
1707: // instance with the valid one.
1708: cacheList.put(key, bundleRef);
1709: }
1710: }
1711: }
1712: return bundle;
1713: }
1714:
1715: private static final void setExpirationTime(CacheKey cacheKey,
1716: Control control) {
1717: long ttl = control.getTimeToLive(cacheKey.getName(), cacheKey
1718: .getLocale());
1719: if (ttl >= 0) {
1720: // If any expiration time is specified, set the time to be
1721: // expired in the cache.
1722: long now = System.currentTimeMillis();
1723: cacheKey.loadTime = now;
1724: cacheKey.expirationTime = now + ttl;
1725: } else if (ttl >= Control.TTL_NO_EXPIRATION_CONTROL) {
1726: cacheKey.expirationTime = ttl;
1727: } else {
1728: throw new IllegalArgumentException("Invalid Control: TTL="
1729: + ttl);
1730: }
1731: }
1732:
1733: /**
1734: * Removes all resource bundles from the cache that have been loaded
1735: * using the caller's class loader.
1736: *
1737: * @since 1.6
1738: * @see ResourceBundle.Control#getTimeToLive(String,Locale)
1739: */
1740: public static final void clearCache() {
1741: clearCache(getLoader());
1742: }
1743:
1744: /**
1745: * Removes all resource bundles from the cache that have been loaded
1746: * using the given class loader.
1747: *
1748: * @param loader the class loader
1749: * @exception NullPointerException if <code>loader</code> is null
1750: * @since 1.6
1751: * @see ResourceBundle.Control#getTimeToLive(String,Locale)
1752: */
1753: public static final void clearCache(ClassLoader loader) {
1754: if (loader == null) {
1755: throw new NullPointerException();
1756: }
1757: Set<CacheKey> set = cacheList.keySet();
1758: for (CacheKey key : set) {
1759: if (key.getLoader() == loader) {
1760: set.remove(key);
1761: }
1762: }
1763: }
1764:
1765: /**
1766: * Gets an object for the given key from this resource bundle.
1767: * Returns null if this resource bundle does not contain an
1768: * object for the given key.
1769: *
1770: * @param key the key for the desired object
1771: * @exception NullPointerException if <code>key</code> is <code>null</code>
1772: * @return the object for the given key, or null
1773: */
1774: protected abstract Object handleGetObject(String key);
1775:
1776: /**
1777: * Returns an enumeration of the keys.
1778: *
1779: * @return an <code>Enumeration</code> of the keys contained in
1780: * this <code>ResourceBundle</code> and its parent bundles.
1781: */
1782: public abstract Enumeration<String> getKeys();
1783:
1784: /**
1785: * Determines whether the given <code>key</code> is contained in
1786: * this <code>ResourceBundle</code> or its parent bundles.
1787: *
1788: * @param key
1789: * the resource <code>key</code>
1790: * @return <code>true</code> if the given <code>key</code> is
1791: * contained in this <code>ResourceBundle</code> or its
1792: * parent bundles; <code>false</code> otherwise.
1793: * @exception NullPointerException
1794: * if <code>key</code> is <code>null</code>
1795: * @since 1.6
1796: */
1797: public boolean containsKey(String key) {
1798: if (key == null) {
1799: throw new NullPointerException();
1800: }
1801: for (ResourceBundle rb = this ; rb != null; rb = rb.parent) {
1802: if (rb.handleKeySet().contains(key)) {
1803: return true;
1804: }
1805: }
1806: return false;
1807: }
1808:
1809: /**
1810: * Returns a <code>Set</code> of all keys contained in this
1811: * <code>ResourceBundle</code> and its parent bundles.
1812: *
1813: * @return a <code>Set</code> of all keys contained in this
1814: * <code>ResourceBundle</code> and its parent bundles.
1815: * @since 1.6
1816: */
1817: public Set<String> keySet() {
1818: Set<String> keys = new HashSet<String>();
1819: for (ResourceBundle rb = this ; rb != null; rb = rb.parent) {
1820: keys.addAll(rb.handleKeySet());
1821: }
1822: return keys;
1823: }
1824:
1825: /**
1826: * Returns a <code>Set</code> of the keys contained <em>only</em>
1827: * in this <code>ResourceBundle</code>.
1828: *
1829: * <p>The default implementation returns a <code>Set</code> of the
1830: * keys returned by the {@link #getKeys() getKeys} method except
1831: * for the ones for which the {@link #handleGetObject(String)
1832: * handleGetObject} method returns <code>null</code>. Once the
1833: * <code>Set</code> has been created, the value is kept in this
1834: * <code>ResourceBundle</code> in order to avoid producing the
1835: * same <code>Set</code> in the next calls. Override this method
1836: * in subclass implementations for faster handling.
1837: *
1838: * @return a <code>Set</code> of the keys contained only in this
1839: * <code>ResourceBundle</code>
1840: * @since 1.6
1841: */
1842: protected Set<String> handleKeySet() {
1843: if (keySet == null) {
1844: synchronized (this ) {
1845: if (keySet == null) {
1846: Set<String> keys = new HashSet<String>();
1847: Enumeration<String> enumKeys = getKeys();
1848: while (enumKeys.hasMoreElements()) {
1849: String key = enumKeys.nextElement();
1850: if (handleGetObject(key) != null) {
1851: keys.add(key);
1852: }
1853: }
1854: keySet = keys;
1855: }
1856: }
1857: }
1858: return keySet;
1859: }
1860:
1861: /**
1862: * <code>ResourceBundle.Control</code> defines a set of callback methods
1863: * that are invoked by the {@link ResourceBundle#getBundle(String,
1864: * Locale, ClassLoader, Control) ResourceBundle.getBundle} factory
1865: * methods during the bundle loading process. In other words, a
1866: * <code>ResourceBundle.Control</code> collaborates with the factory
1867: * methods for loading resource bundles. The default implementation of
1868: * the callback methods provides the information necessary for the
1869: * factory methods to perform the <a
1870: * href="./ResourceBundle.html#default_behavior">default behavior</a>.
1871: *
1872: * <p>In addition to the callback methods, the {@link
1873: * #toBundleName(String, Locale) toBundleName} and {@link
1874: * #toResourceName(String, String) toResourceName} methods are defined
1875: * primarily for convenience in implementing the callback
1876: * methods. However, the <code>toBundleName</code> method could be
1877: * overridden to provide different conventions in the organization and
1878: * packaging of localized resources. The <code>toResourceName</code>
1879: * method is <code>final</code> to avoid use of wrong resource and class
1880: * name separators.
1881: *
1882: * <p>Two factory methods, {@link #getControl(List)} and {@link
1883: * #getNoFallbackControl(List)}, provide
1884: * <code>ResourceBundle.Control</code> instances that implement common
1885: * variations of the default bundle loading process.
1886: *
1887: * <p>The formats returned by the {@link Control#getFormats(String)
1888: * getFormats} method and candidate locales returned by the {@link
1889: * ResourceBundle.Control#getCandidateLocales(String, Locale)
1890: * getCandidateLocales} method must be consistent in all
1891: * <code>ResourceBundle.getBundle</code> invocations for the same base
1892: * bundle. Otherwise, the <code>ResourceBundle.getBundle</code> methods
1893: * may return unintended bundles. For example, if only
1894: * <code>"java.class"</code> is returned by the <code>getFormats</code>
1895: * method for the first call to <code>ResourceBundle.getBundle</code>
1896: * and only <code>"java.properties"</code> for the second call, then the
1897: * second call will return the class-based one that has been cached
1898: * during the first call.
1899: *
1900: * <p>A <code>ResourceBundle.Control</code> instance must be thread-safe
1901: * if it's simultaneously used by multiple threads.
1902: * <code>ResourceBundle.getBundle</code> does not synchronize to call
1903: * the <code>ResourceBundle.Control</code> methods. The default
1904: * implementations of the methods are thread-safe.
1905: *
1906: * <p>Applications can specify <code>ResourceBundle.Control</code>
1907: * instances returned by the <code>getControl</code> factory methods or
1908: * created from a subclass of <code>ResourceBundle.Control</code> to
1909: * customize the bundle loading process. The following are examples of
1910: * changing the default bundle loading process.
1911: *
1912: * <p><b>Example 1</b>
1913: *
1914: * <p>The following code lets <code>ResourceBundle.getBundle</code> look
1915: * up only properties-based resources.
1916: *
1917: * <pre>
1918: * import java.util.*;
1919: * import static java.util.ResourceBundle.Control.*;
1920: * ...
1921: * ResourceBundle bundle =
1922: * ResourceBundle.getBundle("MyResources", new Locale("fr", "CH"),
1923: * ResourceBundle.Control.getControl(FORMAT_PROPERTIES));
1924: * </pre>
1925: *
1926: * Given the resource bundles in the <a
1927: * href="./ResourceBundle.html#default_behavior_example">example</a> in
1928: * the <code>ResourceBundle.getBundle</code> description, this
1929: * <code>ResourceBundle.getBundle</code> call loads
1930: * <code>MyResources_fr_CH.properties</code> whose parent is
1931: * <code>MyResources_fr.properties</code> whose parent is
1932: * <code>MyResources.properties</code>. (<code>MyResources_fr_CH.properties</code>
1933: * is not hidden, but <code>MyResources_fr_CH.class</code> is.)
1934: *
1935: * <p><b>Example 2</b>
1936: *
1937: * <p>The following is an example of loading XML-based bundles
1938: * using {@link Properties#loadFromXML(java.io.InputStream)
1939: * Properties.loadFromXML}.
1940: *
1941: * <pre>
1942: * ResourceBundle rb = ResourceBundle.getBundle("Messages",
1943: * new ResourceBundle.Control() {
1944: * public List<String> getFormats(String baseName) {
1945: * if (baseName == null)
1946: * throw new NullPointerException();
1947: * return Arrays.asList("xml");
1948: * }
1949: * public ResourceBundle newBundle(String baseName,
1950: * Locale locale,
1951: * String format,
1952: * ClassLoader loader,
1953: * boolean reload)
1954: * throws IllegalAccessException,
1955: * InstantiationException,
1956: * IOException {
1957: * if (baseName == null || locale == null
1958: * || format == null || loader == null)
1959: * throw new NullPointerException();
1960: * ResourceBundle bundle = null;
1961: * if (format.equals("xml")) {
1962: * String bundleName = toBundleName(baseName, locale);
1963: * String resourceName = toResourceName(bundleName, format);
1964: * InputStream stream = null;
1965: * if (reload) {
1966: * URL url = loader.getResource(resourceName);
1967: * if (url != null) {
1968: * URLConnection connection = url.openConnection();
1969: * if (connection != null) {
1970: * // Disable caches to get fresh data for
1971: * // reloading.
1972: * connection.setUseCaches(false);
1973: * stream = connection.getInputStream();
1974: * }
1975: * }
1976: * } else {
1977: * stream = loader.getResourceAsStream(resourceName);
1978: * }
1979: * if (stream != null) {
1980: * BufferedInputStream bis = new BufferedInputStream(stream);
1981: * bundle = new XMLResourceBundle(bis);
1982: * bis.close();
1983: * }
1984: * }
1985: * return bundle;
1986: * }
1987: * });
1988: *
1989: * ...
1990: *
1991: * private static class XMLResourceBundle extends ResourceBundle {
1992: * private Properties props;
1993: * XMLResourceBundle(InputStream stream) throws IOException {
1994: * props = new Properties();
1995: * props.loadFromXML(stream);
1996: * }
1997: * protected Object handleGetObject(String key) {
1998: * return props.getProperty(key);
1999: * }
2000: * public Enumeration<String> getKeys() {
2001: * ...
2002: * }
2003: * }
2004: * </pre>
2005: *
2006: * @since 1.6
2007: */
2008: public static class Control {
2009: /**
2010: * The default format <code>List</code>, which contains the strings
2011: * <code>"java.class"</code> and <code>"java.properties"</code>, in
2012: * this order. This <code>List</code> is {@linkplain
2013: * Collections#unmodifiableList(List) unmodifiable}.
2014: *
2015: * @see #getFormats(String)
2016: */
2017: public static final List<String> FORMAT_DEFAULT = Collections
2018: .unmodifiableList(Arrays.asList("java.class",
2019: "java.properties"));
2020:
2021: /**
2022: * The class-only format <code>List</code> containing
2023: * <code>"java.class"</code>. This <code>List</code> is {@linkplain
2024: * Collections#unmodifiableList(List) unmodifiable}.
2025: *
2026: * @see #getFormats(String)
2027: */
2028: public static final List<String> FORMAT_CLASS = Collections
2029: .unmodifiableList(Arrays.asList("java.class"));
2030:
2031: /**
2032: * The properties-only format <code>List</code> containing
2033: * <code>"java.properties"</code>. This <code>List</code> is
2034: * {@linkplain Collections#unmodifiableList(List) unmodifiable}.
2035: *
2036: * @see #getFormats(String)
2037: */
2038: public static final List<String> FORMAT_PROPERTIES = Collections
2039: .unmodifiableList(Arrays.asList("java.properties"));
2040:
2041: /**
2042: * The time-to-live constant for not caching loaded resource bundle
2043: * instances.
2044: *
2045: * @see #getTimeToLive(String, Locale)
2046: */
2047: public static final long TTL_DONT_CACHE = -1;
2048:
2049: /**
2050: * The time-to-live constant for disabling the expiration control
2051: * for loaded resource bundle instances in the cache.
2052: *
2053: * @see #getTimeToLive(String, Locale)
2054: */
2055: public static final long TTL_NO_EXPIRATION_CONTROL = -2;
2056:
2057: private static final Control INSTANCE = new Control();
2058:
2059: /**
2060: * Sole constructor. (For invocation by subclass constructors,
2061: * typically implicit.)
2062: */
2063: protected Control() {
2064: }
2065:
2066: /**
2067: * Returns a <code>ResourceBundle.Control</code> in which the {@link
2068: * #getFormats(String) getFormats} method returns the specified
2069: * <code>formats</code>. The <code>formats</code> must be equal to
2070: * one of {@link Control#FORMAT_PROPERTIES}, {@link
2071: * Control#FORMAT_CLASS} or {@link
2072: * Control#FORMAT_DEFAULT}. <code>ResourceBundle.Control</code>
2073: * instances returned by this method are singletons and thread-safe.
2074: *
2075: * <p>Specifying {@link Control#FORMAT_DEFAULT} is equivalent to
2076: * instantiating the <code>ResourceBundle.Control</code> class,
2077: * except that this method returns a singleton.
2078: *
2079: * @param formats
2080: * the formats to be returned by the
2081: * <code>ResourceBundle.Control.getFormats</code> method
2082: * @return a <code>ResourceBundle.Control</code> supporting the
2083: * specified <code>formats</code>
2084: * @exception NullPointerException
2085: * if <code>formats</code> is <code>null</code>
2086: * @exception IllegalArgumentException
2087: * if <code>formats</code> is unknown
2088: */
2089: public static final Control getControl(List<String> formats) {
2090: if (formats.equals(Control.FORMAT_PROPERTIES)) {
2091: return SingleFormatControl.PROPERTIES_ONLY;
2092: }
2093: if (formats.equals(Control.FORMAT_CLASS)) {
2094: return SingleFormatControl.CLASS_ONLY;
2095: }
2096: if (formats.equals(Control.FORMAT_DEFAULT)) {
2097: return Control.INSTANCE;
2098: }
2099: throw new IllegalArgumentException();
2100: }
2101:
2102: /**
2103: * Returns a <code>ResourceBundle.Control</code> in which the {@link
2104: * #getFormats(String) getFormats} method returns the specified
2105: * <code>formats</code> and the {@link
2106: * Control#getFallbackLocale(String, Locale) getFallbackLocale}
2107: * method returns <code>null</code>. The <code>formats</code> must
2108: * be equal to one of {@link Control#FORMAT_PROPERTIES}, {@link
2109: * Control#FORMAT_CLASS} or {@link Control#FORMAT_DEFAULT}.
2110: * <code>ResourceBundle.Control</code> instances returned by this
2111: * method are singletons and thread-safe.
2112: *
2113: * @param formats
2114: * the formats to be returned by the
2115: * <code>ResourceBundle.Control.getFormats</code> method
2116: * @return a <code>ResourceBundle.Control</code> supporting the
2117: * specified <code>formats</code> with no fallback
2118: * <code>Locale</code> support
2119: * @exception NullPointerException
2120: * if <code>formats</code> is <code>null</code>
2121: * @exception IllegalArgumentException
2122: * if <code>formats</code> is unknown
2123: */
2124: public static final Control getNoFallbackControl(
2125: List<String> formats) {
2126: if (formats.equals(Control.FORMAT_DEFAULT)) {
2127: return NoFallbackControl.NO_FALLBACK;
2128: }
2129: if (formats.equals(Control.FORMAT_PROPERTIES)) {
2130: return NoFallbackControl.PROPERTIES_ONLY_NO_FALLBACK;
2131: }
2132: if (formats.equals(Control.FORMAT_CLASS)) {
2133: return NoFallbackControl.CLASS_ONLY_NO_FALLBACK;
2134: }
2135: throw new IllegalArgumentException();
2136: }
2137:
2138: /**
2139: * Returns a <code>List</code> of <code>String</code>s containing
2140: * formats to be used to load resource bundles for the given
2141: * <code>baseName</code>. The <code>ResourceBundle.getBundle</code>
2142: * factory method tries to load resource bundles with formats in the
2143: * order specified by the list. The list returned by this method
2144: * must have at least one <code>String</code>. The predefined
2145: * formats are <code>"java.class"</code> for class-based resource
2146: * bundles and <code>"java.properties"</code> for {@linkplain
2147: * PropertyResourceBundle properties-based} ones. Strings starting
2148: * with <code>"java."</code> are reserved for future extensions and
2149: * must not be used by application-defined formats.
2150: *
2151: * <p>It is not a requirement to return an immutable (unmodifiable)
2152: * <code>List</code>. However, the returned <code>List</code> must
2153: * not be mutated after it has been returned by
2154: * <code>getFormats</code>.
2155: *
2156: * <p>The default implementation returns {@link #FORMAT_DEFAULT} so
2157: * that the <code>ResourceBundle.getBundle</code> factory method
2158: * looks up first class-based resource bundles, then
2159: * properties-based ones.
2160: *
2161: * @param baseName
2162: * the base name of the resource bundle, a fully qualified class
2163: * name
2164: * @return a <code>List</code> of <code>String</code>s containing
2165: * formats for loading resource bundles.
2166: * @exception NullPointerException
2167: * if <code>baseName</code> is null
2168: * @see #FORMAT_DEFAULT
2169: * @see #FORMAT_CLASS
2170: * @see #FORMAT_PROPERTIES
2171: */
2172: public List<String> getFormats(String baseName) {
2173: if (baseName == null) {
2174: throw new NullPointerException();
2175: }
2176: return FORMAT_DEFAULT;
2177: }
2178:
2179: /**
2180: * Returns a <code>List</code> of <code>Locale</code>s as candidate
2181: * locales for <code>baseName</code> and <code>locale</code>. This
2182: * method is called by the <code>ResourceBundle.getBundle</code>
2183: * factory method each time the factory method tries finding a
2184: * resource bundle for a target <code>Locale</code>.
2185: *
2186: * <p>The sequence of the candidate locales also corresponds to the
2187: * runtime resource lookup path (also known as the <I>parent
2188: * chain</I>), if the corresponding resource bundles for the
2189: * candidate locales exist and their parents are not defined by
2190: * loaded resource bundles themselves. The last element of the list
2191: * must be a {@linkplain Locale#ROOT root locale} if it is desired to
2192: * have the base bundle as the terminal of the parent chain.
2193: *
2194: * <p>If the given locale is equal to <code>Locale.ROOT</code> (the
2195: * root locale), a <code>List</code> containing only the root
2196: * <code>Locale</code> must be returned. In this case, the
2197: * <code>ResourceBundle.getBundle</code> factory method loads only
2198: * the base bundle as the resulting resource bundle.
2199: *
2200: * <p>It is not a requirement to return an immutable
2201: * (unmodifiable) <code>List</code>. However, the returned
2202: * <code>List</code> must not be mutated after it has been
2203: * returned by <code>getCandidateLocales</code>.
2204: *
2205: * <p>The default implementation returns a <code>List</code> containing
2206: * <code>Locale</code>s in the following sequence:
2207: * <pre>
2208: * Locale(language, country, variant)
2209: * Locale(language, country)
2210: * Locale(language)
2211: * Locale.ROOT
2212: * </pre>
2213: * where <code>language</code>, <code>country</code> and
2214: * <code>variant</code> are the language, country and variant values
2215: * of the given <code>locale</code>, respectively. Locales where the
2216: * final component values are empty strings are omitted.
2217: *
2218: * <p>The default implementation uses an {@link ArrayList} that
2219: * overriding implementations may modify before returning it to the
2220: * caller. However, a subclass must not modify it after it has
2221: * been returned by <code>getCandidateLocales</code>.
2222: *
2223: * <p>For example, if the given <code>baseName</code> is "Messages"
2224: * and the given <code>locale</code> is
2225: * <code>Locale("ja", "", "XX")</code>, then a
2226: * <code>List</code> of <code>Locale</code>s:
2227: * <pre>
2228: * Locale("ja", "", "XX")
2229: * Locale("ja")
2230: * Locale.ROOT
2231: * </pre>
2232: * is returned. And if the resource bundles for the "ja" and
2233: * "" <code>Locale</code>s are found, then the runtime resource
2234: * lookup path (parent chain) is:
2235: * <pre>
2236: * Messages_ja -> Messages
2237: * </pre>
2238: *
2239: * @param baseName
2240: * the base name of the resource bundle, a fully
2241: * qualified class name
2242: * @param locale
2243: * the locale for which a resource bundle is desired
2244: * @return a <code>List</code> of candidate
2245: * <code>Locale</code>s for the given <code>locale</code>
2246: * @exception NullPointerException
2247: * if <code>baseName</code> or <code>locale</code> is
2248: * <code>null</code>
2249: */
2250: public List<Locale> getCandidateLocales(String baseName,
2251: Locale locale) {
2252: if (baseName == null) {
2253: throw new NullPointerException();
2254: }
2255: String language = locale.getLanguage();
2256: String country = locale.getCountry();
2257: String variant = locale.getVariant();
2258:
2259: List<Locale> locales = new ArrayList<Locale>(4);
2260: if (variant.length() > 0) {
2261: locales.add(locale);
2262: }
2263: if (country.length() > 0) {
2264: locales.add((locales.size() == 0) ? locale : Locale
2265: .getInstance(language, country, ""));
2266: }
2267: if (language.length() > 0) {
2268: locales.add((locales.size() == 0) ? locale : Locale
2269: .getInstance(language, "", ""));
2270: }
2271: locales.add(Locale.ROOT);
2272: return locales;
2273: }
2274:
2275: /**
2276: * Returns a <code>Locale</code> to be used as a fallback locale for
2277: * further resource bundle searches by the
2278: * <code>ResourceBundle.getBundle</code> factory method. This method
2279: * is called from the factory method every time when no resulting
2280: * resource bundle has been found for <code>baseName</code> and
2281: * <code>locale</code>, where locale is either the parameter for
2282: * <code>ResourceBundle.getBundle</code> or the previous fallback
2283: * locale returned by this method.
2284: *
2285: * <p>The method returns <code>null</code> if no further fallback
2286: * search is desired.
2287: *
2288: * <p>The default implementation returns the {@linkplain
2289: * Locale#getDefault() default <code>Locale</code>} if the given
2290: * <code>locale</code> isn't the default one. Otherwise,
2291: * <code>null</code> is returned.
2292: *
2293: * @param baseName
2294: * the base name of the resource bundle, a fully
2295: * qualified class name for which
2296: * <code>ResourceBundle.getBundle</code> has been
2297: * unable to find any resource bundles (except for the
2298: * base bundle)
2299: * @param locale
2300: * the <code>Locale</code> for which
2301: * <code>ResourceBundle.getBundle</code> has been
2302: * unable to find any resource bundles (except for the
2303: * base bundle)
2304: * @return a <code>Locale</code> for the fallback search,
2305: * or <code>null</code> if no further fallback search
2306: * is desired.
2307: * @exception NullPointerException
2308: * if <code>baseName</code> or <code>locale</code>
2309: * is <code>null</code>
2310: */
2311: public Locale getFallbackLocale(String baseName, Locale locale) {
2312: if (baseName == null) {
2313: throw new NullPointerException();
2314: }
2315: Locale defaultLocale = Locale.getDefault();
2316: return locale.equals(defaultLocale) ? null : defaultLocale;
2317: }
2318:
2319: /**
2320: * Instantiates a resource bundle for the given bundle name of the
2321: * given format and locale, using the given class loader if
2322: * necessary. This method returns <code>null</code> if there is no
2323: * resource bundle available for the given parameters. If a resource
2324: * bundle can't be instantiated due to an unexpected error, the
2325: * error must be reported by throwing an <code>Error</code> or
2326: * <code>Exception</code> rather than simply returning
2327: * <code>null</code>.
2328: *
2329: * <p>If the <code>reload</code> flag is <code>true</code>, it
2330: * indicates that this method is being called because the previously
2331: * loaded resource bundle has expired.
2332: *
2333: * <p>The default implementation instantiates a
2334: * <code>ResourceBundle</code> as follows.
2335: *
2336: * <ul>
2337: *
2338: * <li>The bundle name is obtained by calling {@link
2339: * #toBundleName(String, Locale) toBundleName(baseName,
2340: * locale)}.</li>
2341: *
2342: * <li>If <code>format</code> is <code>"java.class"</code>, the
2343: * {@link Class} specified by the bundle name is loaded by calling
2344: * {@link ClassLoader#loadClass(String)}. Then, a
2345: * <code>ResourceBundle</code> is instantiated by calling {@link
2346: * Class#newInstance()}. Note that the <code>reload</code> flag is
2347: * ignored for loading class-based resource bundles in this default
2348: * implementation.</li>
2349: *
2350: * <li>If <code>format</code> is <code>"java.properties"</code>,
2351: * {@link #toResourceName(String, String) toResourceName(bundlename,
2352: * "properties")} is called to get the resource name.
2353: * If <code>reload</code> is <code>true</code>, {@link
2354: * ClassLoader#getResource(String) load.getResource} is called
2355: * to get a {@link URL} for creating a {@link
2356: * URLConnection}. This <code>URLConnection</code> is used to
2357: * {@linkplain URLConnection#setUseCaches(boolean) disable the
2358: * caches} of the underlying resource loading layers,
2359: * and to {@linkplain URLConnection#getInputStream() get an
2360: * <code>InputStream</code>}.
2361: * Otherwise, {@link ClassLoader#getResourceAsStream(String)
2362: * loader.getResourceAsStream} is called to get an {@link
2363: * InputStream}. Then, a {@link
2364: * PropertyResourceBundle} is constructed with the
2365: * <code>InputStream</code>.</li>
2366: *
2367: * <li>If <code>format</code> is neither <code>"java.class"</code>
2368: * nor <code>"java.properties"</code>, an
2369: * <code>IllegalArgumentException</code> is thrown.</li>
2370: *
2371: * </ul>
2372: *
2373: * @param baseName
2374: * the base bundle name of the resource bundle, a fully
2375: * qualified class name
2376: * @param locale
2377: * the locale for which the resource bundle should be
2378: * instantiated
2379: * @param format
2380: * the resource bundle format to be loaded
2381: * @param loader
2382: * the <code>ClassLoader</code> to use to load the bundle
2383: * @param reload
2384: * the flag to indicate bundle reloading; <code>true</code>
2385: * if reloading an expired resource bundle,
2386: * <code>false</code> otherwise
2387: * @return the resource bundle instance,
2388: * or <code>null</code> if none could be found.
2389: * @exception NullPointerException
2390: * if <code>bundleName</code>, <code>locale</code>,
2391: * <code>format</code>, or <code>loader</code> is
2392: * <code>null</code>, or if <code>null</code> is returned by
2393: * {@link #toBundleName(String, Locale) toBundleName}
2394: * @exception IllegalArgumentException
2395: * if <code>format</code> is unknown, or if the resource
2396: * found for the given parameters contains malformed data.
2397: * @exception ClassCastException
2398: * if the loaded class cannot be cast to <code>ResourceBundle</code>
2399: * @exception IllegalAccessException
2400: * if the class or its nullary constructor is not
2401: * accessible.
2402: * @exception InstantiationException
2403: * if the instantiation of a class fails for some other
2404: * reason.
2405: * @exception ExceptionInInitializerError
2406: * if the initialization provoked by this method fails.
2407: * @exception SecurityException
2408: * If a security manager is present and creation of new
2409: * instances is denied. See {@link Class#newInstance()}
2410: * for details.
2411: * @exception IOException
2412: * if an error occurred when reading resources using
2413: * any I/O operations
2414: */
2415: public ResourceBundle newBundle(String baseName, Locale locale,
2416: String format, ClassLoader loader, boolean reload)
2417: throws IllegalAccessException, InstantiationException,
2418: IOException {
2419: String bundleName = toBundleName(baseName, locale);
2420: ResourceBundle bundle = null;
2421: if (format.equals("java.class")) {
2422: try {
2423: Class<? extends ResourceBundle> bundleClass = (Class<? extends ResourceBundle>) loader
2424: .loadClass(bundleName);
2425:
2426: // If the class isn't a ResourceBundle subclass, throw a
2427: // ClassCastException.
2428: if (ResourceBundle.class
2429: .isAssignableFrom(bundleClass)) {
2430: bundle = bundleClass.newInstance();
2431: } else {
2432: throw new ClassCastException(bundleClass
2433: .getName()
2434: + " cannot be cast to ResourceBundle");
2435: }
2436: } catch (ClassNotFoundException e) {
2437: }
2438: } else if (format.equals("java.properties")) {
2439: final String resourceName = toResourceName(bundleName,
2440: "properties");
2441: final ClassLoader classLoader = loader;
2442: final boolean reloadFlag = reload;
2443: InputStream stream = null;
2444: try {
2445: stream = AccessController
2446: .doPrivileged(new PrivilegedExceptionAction<InputStream>() {
2447: public InputStream run()
2448: throws IOException {
2449: InputStream is = null;
2450: if (reloadFlag) {
2451: URL url = classLoader
2452: .getResource(resourceName);
2453: if (url != null) {
2454: URLConnection connection = url
2455: .openConnection();
2456: if (connection != null) {
2457: // Disable caches to get fresh data for
2458: // reloading.
2459: connection
2460: .setUseCaches(false);
2461: is = connection
2462: .getInputStream();
2463: }
2464: }
2465: } else {
2466: is = classLoader
2467: .getResourceAsStream(resourceName);
2468: }
2469: return is;
2470: }
2471: });
2472: } catch (PrivilegedActionException e) {
2473: throw (IOException) e.getException();
2474: }
2475: if (stream != null) {
2476: try {
2477: bundle = new PropertyResourceBundle(stream);
2478: } finally {
2479: stream.close();
2480: }
2481: }
2482: } else {
2483: throw new IllegalArgumentException("unknown format: "
2484: + format);
2485: }
2486: return bundle;
2487: }
2488:
2489: /**
2490: * Returns the time-to-live (TTL) value for resource bundles that
2491: * are loaded under this
2492: * <code>ResourceBundle.Control</code>. Positive time-to-live values
2493: * specify the number of milliseconds a bundle can remain in the
2494: * cache without being validated against the source data from which
2495: * it was constructed. The value 0 indicates that a bundle must be
2496: * validated each time it is retrieved from the cache. {@link
2497: * #TTL_DONT_CACHE} specifies that loaded resource bundles are not
2498: * put in the cache. {@link #TTL_NO_EXPIRATION_CONTROL} specifies
2499: * that loaded resource bundles are put in the cache with no
2500: * expiration control.
2501: *
2502: * <p>The expiration affects only the bundle loading process by the
2503: * <code>ResourceBundle.getBundle</code> factory method. That is,
2504: * if the factory method finds a resource bundle in the cache that
2505: * has expired, the factory method calls the {@link
2506: * #needsReload(String, Locale, String, ClassLoader, ResourceBundle,
2507: * long) needsReload} method to determine whether the resource
2508: * bundle needs to be reloaded. If <code>needsReload</code> returns
2509: * <code>true</code>, the cached resource bundle instance is removed
2510: * from the cache. Otherwise, the instance stays in the cache,
2511: * updated with the new TTL value returned by this method.
2512: *
2513: * <p>All cached resource bundles are subject to removal from the
2514: * cache due to memory constraints of the runtime environment.
2515: * Returning a large positive value doesn't mean to lock loaded
2516: * resource bundles in the cache.
2517: *
2518: * <p>The default implementation returns {@link #TTL_NO_EXPIRATION_CONTROL}.
2519: *
2520: * @param baseName
2521: * the base name of the resource bundle for which the
2522: * expiration value is specified.
2523: * @param locale
2524: * the locale of the resource bundle for which the
2525: * expiration value is specified.
2526: * @return the time (0 or a positive millisecond offset from the
2527: * cached time) to get loaded bundles expired in the cache,
2528: * {@link #TTL_NO_EXPIRATION_CONTROL} to disable the
2529: * expiration control, or {@link #TTL_DONT_CACHE} to disable
2530: * caching.
2531: * @exception NullPointerException
2532: * if <code>baseName</code> or <code>locale</code> is
2533: * <code>null</code>
2534: */
2535: public long getTimeToLive(String baseName, Locale locale) {
2536: if (baseName == null || locale == null) {
2537: throw new NullPointerException();
2538: }
2539: return TTL_NO_EXPIRATION_CONTROL;
2540: }
2541:
2542: /**
2543: * Determines if the expired <code>bundle</code> in the cache needs
2544: * to be reloaded based on the loading time given by
2545: * <code>loadTime</code> or some other criteria. The method returns
2546: * <code>true</code> if reloading is required; <code>false</code>
2547: * otherwise. <code>loadTime</code> is a millisecond offset since
2548: * the <a href="Calendar.html#Epoch"> <code>Calendar</code>
2549: * Epoch</a>.
2550: *
2551: * The calling <code>ResourceBundle.getBundle</code> factory method
2552: * calls this method on the <code>ResourceBundle.Control</code>
2553: * instance used for its current invocation, not on the instance
2554: * used in the invocation that originally loaded the resource
2555: * bundle.
2556: *
2557: * <p>The default implementation compares <code>loadTime</code> and
2558: * the last modified time of the source data of the resource
2559: * bundle. If it's determined that the source data has been modified
2560: * since <code>loadTime</code>, <code>true</code> is
2561: * returned. Otherwise, <code>false</code> is returned. This
2562: * implementation assumes that the given <code>format</code> is the
2563: * same string as its file suffix if it's not one of the default
2564: * formats, <code>"java.class"</code> or
2565: * <code>"java.properties"</code>.
2566: *
2567: * @param baseName
2568: * the base bundle name of the resource bundle, a
2569: * fully qualified class name
2570: * @param locale
2571: * the locale for which the resource bundle
2572: * should be instantiated
2573: * @param format
2574: * the resource bundle format to be loaded
2575: * @param loader
2576: * the <code>ClassLoader</code> to use to load the bundle
2577: * @param bundle
2578: * the resource bundle instance that has been expired
2579: * in the cache
2580: * @param loadTime
2581: * the time when <code>bundle</code> was loaded and put
2582: * in the cache
2583: * @return <code>true</code> if the expired bundle needs to be
2584: * reloaded; <code>false</code> otherwise.
2585: * @exception NullPointerException
2586: * if <code>baseName</code>, <code>locale</code>,
2587: * <code>format</code>, <code>loader</code>, or
2588: * <code>bundle</code> is <code>null</code>
2589: */
2590: public boolean needsReload(String baseName, Locale locale,
2591: String format, ClassLoader loader,
2592: ResourceBundle bundle, long loadTime) {
2593: if (bundle == null) {
2594: throw new NullPointerException();
2595: }
2596: if (format.equals("java.class")
2597: || format.equals("java.properties")) {
2598: format = format.substring(5);
2599: }
2600: boolean result = false;
2601: try {
2602: String resourceName = toResourceName(toBundleName(
2603: baseName, locale), format);
2604: URL url = loader.getResource(resourceName);
2605: if (url != null) {
2606: long lastModified = 0;
2607: URLConnection connection = url.openConnection();
2608: if (connection != null) {
2609: // disable caches to get the correct data
2610: connection.setUseCaches(false);
2611: if (connection instanceof JarURLConnection) {
2612: JarEntry ent = ((JarURLConnection) connection)
2613: .getJarEntry();
2614: if (ent != null) {
2615: lastModified = ent.getTime();
2616: if (lastModified == -1) {
2617: lastModified = 0;
2618: }
2619: }
2620: } else {
2621: lastModified = connection.getLastModified();
2622: }
2623: }
2624: result = lastModified >= loadTime;
2625: }
2626: } catch (NullPointerException npe) {
2627: throw npe;
2628: } catch (Exception e) {
2629: // ignore other exceptions
2630: }
2631: return result;
2632: }
2633:
2634: /**
2635: * Converts the given <code>baseName</code> and <code>locale</code>
2636: * to the bundle name. This method is called from the default
2637: * implementation of the {@link #newBundle(String, Locale, String,
2638: * ClassLoader, boolean) newBundle} and {@link #needsReload(String,
2639: * Locale, String, ClassLoader, ResourceBundle, long) needsReload}
2640: * methods.
2641: *
2642: * <p>This implementation returns the following value:
2643: * <pre>
2644: * baseName + "_" + language + "_" + country + "_" + variant
2645: * </pre>
2646: * where <code>language</code>, <code>country</code> and
2647: * <code>variant</code> are the language, country and variant values
2648: * of <code>locale</code>, respectively. Final component values that
2649: * are empty Strings are omitted along with the preceding '_'. If
2650: * all of the values are empty strings, then <code>baseName</code>
2651: * is returned.
2652: *
2653: * <p>For example, if <code>baseName</code> is
2654: * <code>"baseName"</code> and <code>locale</code> is
2655: * <code>Locale("ja", "", "XX")</code>, then
2656: * <code>"baseName_ja_ _XX"</code> is returned. If the given
2657: * locale is <code>Locale("en")</code>, then
2658: * <code>"baseName_en"</code> is returned.
2659: *
2660: * <p>Overriding this method allows applications to use different
2661: * conventions in the organization and packaging of localized
2662: * resources.
2663: *
2664: * @param baseName
2665: * the base name of the resource bundle, a fully
2666: * qualified class name
2667: * @param locale
2668: * the locale for which a resource bundle should be
2669: * loaded
2670: * @return the bundle name for the resource bundle
2671: * @exception NullPointerException
2672: * if <code>baseName</code> or <code>locale</code>
2673: * is <code>null</code>
2674: */
2675: public String toBundleName(String baseName, Locale locale) {
2676: if (locale == Locale.ROOT) {
2677: return baseName;
2678: }
2679:
2680: String language = locale.getLanguage();
2681: String country = locale.getCountry();
2682: String variant = locale.getVariant();
2683:
2684: if (language == "" && country == "" && variant == "") {
2685: return baseName;
2686: }
2687:
2688: StringBuilder sb = new StringBuilder(baseName);
2689: sb.append('_');
2690: if (variant != "") {
2691: sb.append(language).append('_').append(country).append(
2692: '_').append(variant);
2693: } else if (country != "") {
2694: sb.append(language).append('_').append(country);
2695: } else {
2696: sb.append(language);
2697: }
2698: return sb.toString();
2699:
2700: }
2701:
2702: /**
2703: * Converts the given <code>bundleName</code> to the form required
2704: * by the {@link ClassLoader#getResource ClassLoader.getResource}
2705: * method by replacing all occurrences of <code>'.'</code> in
2706: * <code>bundleName</code> with <code>'/'</code> and appending a
2707: * <code>'.'</code> and the given file <code>suffix</code>. For
2708: * example, if <code>bundleName</code> is
2709: * <code>"foo.bar.MyResources_ja_JP"</code> and <code>suffix</code>
2710: * is <code>"properties"</code>, then
2711: * <code>"foo/bar/MyResources_ja_JP.properties"</code> is returned.
2712: *
2713: * @param bundleName
2714: * the bundle name
2715: * @param suffix
2716: * the file type suffix
2717: * @return the converted resource name
2718: * @exception NullPointerException
2719: * if <code>bundleName</code> or <code>suffix</code>
2720: * is <code>null</code>
2721: */
2722: public final String toResourceName(String bundleName,
2723: String suffix) {
2724: StringBuilder sb = new StringBuilder(bundleName.length()
2725: + 1 + suffix.length());
2726: sb.append(bundleName.replace('.', '/')).append('.').append(
2727: suffix);
2728: return sb.toString();
2729: }
2730: }
2731:
2732: private static class SingleFormatControl extends Control {
2733: private static final Control PROPERTIES_ONLY = new SingleFormatControl(
2734: FORMAT_PROPERTIES);
2735:
2736: private static final Control CLASS_ONLY = new SingleFormatControl(
2737: FORMAT_CLASS);
2738:
2739: private final List<String> formats;
2740:
2741: protected SingleFormatControl(List<String> formats) {
2742: this .formats = formats;
2743: }
2744:
2745: public List<String> getFormats(String baseName) {
2746: if (baseName == null) {
2747: throw new NullPointerException();
2748: }
2749: return formats;
2750: }
2751: }
2752:
2753: private static final class NoFallbackControl extends
2754: SingleFormatControl {
2755: private static final Control NO_FALLBACK = new NoFallbackControl(
2756: FORMAT_DEFAULT);
2757:
2758: private static final Control PROPERTIES_ONLY_NO_FALLBACK = new NoFallbackControl(
2759: FORMAT_PROPERTIES);
2760:
2761: private static final Control CLASS_ONLY_NO_FALLBACK = new NoFallbackControl(
2762: FORMAT_CLASS);
2763:
2764: protected NoFallbackControl(List<String> formats) {
2765: super (formats);
2766: }
2767:
2768: public Locale getFallbackLocale(String baseName, Locale locale) {
2769: if (baseName == null || locale == null) {
2770: throw new NullPointerException();
2771: }
2772: return null;
2773: }
2774: }
2775: }
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