/*
*
* @(#)ResourceBundle.java 1.74 06/10/10
*
* Portions Copyright 2000-2008 Sun Microsystems, Inc. All Rights
* Reserved. Use is subject to license terms.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
/*
* (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
* (C) Copyright IBM Corp. 1996 - 1999 - All Rights Reserved
*
* The original version of this source code and documentation
* is copyrighted and owned by Taligent, Inc., a wholly-owned
* subsidiary of IBM. These materials are provided under terms
* of a License Agreement between Taligent and Sun. This technology
* is protected by multiple US and International patents.
*
* This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
*/
package java.util;
import java.io.InputStream;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import sun.misc.SoftCache;
/**
*
* Resource bundles contain locale-specific objects.
* When your program needs a locale-specific resource,
* a <code>String</code> for example, your program can load it
* from the resource bundle that is appropriate for the
* current user's locale. In this way, you can write
* program code that is largely independent of the user's
* locale isolating most, if not all, of the locale-specific
* information in resource bundles.
*
* <p>
* This allows you to write programs that can:
* <UL type=SQUARE>
* <LI> be easily localized, or translated, into different languages
* <LI> handle multiple locales at once
* <LI> be easily modified later to support even more locales
* </UL>
*
* <P>
* Resource bundles belong to families whose members share a common base
* name, but whose names also have additional components that identify
* their locales. For example, the base name of a family of resource
* bundles might be "MyResources". The family should have a default
* resource bundle which simply has the same name as its family -
* "MyResources" - and will be used as the bundle of last resort if a
* specific locale is not supported. The family can then provide as
* many locale-specific members as needed, for example a German one
* named "MyResources_de".
*
* <P>
* Each resource bundle in a family contains the same items, but the items have
* been translated for the locale represented by that resource bundle.
* For example, both "MyResources" and "MyResources_de" may have a
* <code>String</code> that's used on a button for canceling operations.
* In "MyResources" the <code>String</code> may contain "Cancel" and in
* "MyResources_de" it may contain "Abbrechen".
*
* <P>
* If there are different resources for different countries, you
* can make specializations: for example, "MyResources_de_CH" contains objects for
* the German language (de) in Switzerland (CH). If you want to only
* modify some of the resources
* in the specialization, you can do so.
*
* <P>
* When your program needs a locale-specific object, it loads
* the <code>ResourceBundle</code> class using the
* {@link #getBundle(java.lang.String, java.util.Locale) getBundle}
* method:
* <blockquote>
* <pre>
* ResourceBundle myResources =
* ResourceBundle.getBundle("MyResources", currentLocale);
* </pre>
* </blockquote>
*
* <P>
* Resource bundles contain key/value pairs. The keys uniquely
* identify a locale-specific object in the bundle. Here's an
* example of a <code>ListResourceBundle</code> that contains
* two key/value pairs:
* <blockquote>
* <pre>
* public class MyResources extends ListResourceBundle {
* public Object[][] getContents() {
* return contents;
* }
* static final Object[][] contents = {
* // LOCALIZE THIS
* {"OkKey", "OK"},
* {"CancelKey", "Cancel"},
* // END OF MATERIAL TO LOCALIZE
* };
* }
* </pre>
* </blockquote>
* Keys are always <code>String</code>s.
* In this example, the keys are "OkKey" and "CancelKey".
* In the above example, the values
* are also <code>String</code>s--"OK" and "Cancel"--but
* they don't have to be. The values can be any type of object.
*
* <P>
* You retrieve an object from resource bundle using the appropriate
* getter method. Because "OkKey" and "CancelKey"
* are both strings, you would use <code>getString</code> to retrieve them:
* <blockquote>
* <pre>
* button1 = new Button(myResources.getString("OkKey"));
* button2 = new Button(myResources.getString("CancelKey"));
* </pre>
* </blockquote>
* The getter methods all require the key as an argument and return
* the object if found. If the object is not found, the getter method
* throws a <code>MissingResourceException</code>.
*
* <P>
* Besides <code>getString</code>, ResourceBundle also provides
* a method for getting string arrays, <code>getStringArray</code>,
* as well as a generic <code>getObject</code> method for any other
* type of object. When using <code>getObject</code>, you'll
* have to cast the result to the appropriate type. For example:
* <blockquote>
* <pre>
* int[] myIntegers = (int[]) myResources.getObject("intList");
* </pre>
* </blockquote>
*
* <P>
* The Java 2 platform provides two subclasses of <code>ResourceBundle</code>,
* <code>ListResourceBundle</code> and <code>PropertyResourceBundle</code>,
* that provide a fairly simple way to create resources.
* As you saw briefly in a previous example, <code>ListResourceBundle</code>
* manages its resource as a List of key/value pairs.
* <code>PropertyResourceBundle</code> uses a properties file to manage
* its resources.
*
* <p>
* If <code>ListResourceBundle</code> or <code>PropertyResourceBundle</code>
* do not suit your needs, you can write your own <code>ResourceBundle</code>
* subclass. Your subclasses must override two methods: <code>handleGetObject</code>
* and <code>getKeys()</code>.
*
* <P>
* The following is a very simple example of a <code>ResourceBundle</code>
* subclass, MyResources, that manages two resources (for a larger number of
* resources you would probably use a <code>Hashtable</code>).
* Notice that you don't need to supply a value if
* a "parent-level" <code>ResourceBundle</code> handles the same
* key with the same value (as for the okKey below).
* <p><strong>Example:</strong>
* <blockquote>
* <pre>
* // default (English language, United States)
* public class MyResources extends ResourceBundle {
* public Object handleGetObject(String key) {
* if (key.equals("okKey")) return "Ok";
* if (key.equals("cancelKey")) return "Cancel";
* return null;
* }
* }
*
* // German language
* public class MyResources_de extends MyResources {
* public Object handleGetObject(String key) {
* // don't need okKey, since parent level handles it.
* if (key.equals("cancelKey")) return "Abbrechen";
* return null;
* }
* }
* </pre>
* </blockquote>
* You do not have to restrict yourself to using a single family of
* <code>ResourceBundle</code>s. For example, you could have a set of bundles for
* exception messages, <code>ExceptionResources</code>
* (<code>ExceptionResources_fr</code>, <code>ExceptionResources_de</code>, ...),
* and one for widgets, <code>WidgetResource</code> (<code>WidgetResources_fr</code>,
* <code>WidgetResources_de</code>, ...); breaking up the resources however you like.
*
* @see ListResourceBundle
* @see PropertyResourceBundle
* @see MissingResourceException
* @since JDK1.1
*/
abstract public class ResourceBundle {
/**
* Static key used for resource lookups. Concurrent
* access to this object is controlled by synchronizing cacheList,
* not cacheKey. A static object is used to do cache lookups
* for performance reasons - the assumption being that synchronization
* has a lower overhead than object allocation and subsequent
* garbage collection.
*/
private static final ResourceCacheKey cacheKey = new ResourceCacheKey();
/** initial size of the bundle cache */
private static final int INITIAL_CACHE_SIZE = 25;
/** capacity of cache consumed before it should grow */
private static final float CACHE_LOAD_FACTOR = (float)1.0;
/**
* Maximum length of one branch of the resource search path tree.
* Used in getBundle.
*/
private static final int MAX_BUNDLES_SEARCHED = 3;
/**
* This Hashtable is used to keep multiple threads from loading the
* same bundle concurrently. The table entries are (cacheKey, thread)
* where cacheKey is the key for the bundle that is under construction
* and thread is the thread that is constructing the bundle.
* This list is manipulated in findBundle and putBundleInCache.
* Synchronization of this object is done through cacheList, not on
* this object.
*/
private static final Hashtable underConstruction = new Hashtable(MAX_BUNDLES_SEARCHED, CACHE_LOAD_FACTOR);
/** constant indicating that no resource bundle was found */
private static final Object NOT_FOUND = new Object();
/**
* The cache is a map from cache keys (with bundle base name,
* locale, and class loader) to either a resource bundle
* (if one has been found) or NOT_FOUND (if no bundle has
* been found).
* The cache is a SoftCache, allowing bundles to be
* removed from the cache if they are no longer
* needed. This will also allow the cache keys
* to be reclaimed along with the ClassLoaders
* they reference.
* This variable would be better named "cache", but we keep the old
* name for compatibility with some workarounds for bug 4212439.
*/
private static SoftCache cacheList = new SoftCache(INITIAL_CACHE_SIZE, CACHE_LOAD_FACTOR);
/**
* Queue for reference objects referring to class loaders.
*/
private static ReferenceQueue referenceQueue = new ReferenceQueue();
/**
* The parent bundle of this bundle.
* The parent bundle is searched by {@link #getObject getObject}
* when this bundle does not contain a particular resource.
*/
protected ResourceBundle parent = null;
/**
* The locale for this bundle.
*/
private Locale locale = null;
/**
* Sole constructor. (For invocation by subclass constructors, typically
* implicit.)
*/
public ResourceBundle() {
}
/**
* Gets a string for the given key from this resource bundle or one of its parents.
* Calling this method is equivalent to calling
* <blockquote>
* <code>(String) {@link #getObject(java.lang.String) getObject}(key)</code>.
* </blockquote>
*
* @param key the key for the desired string
* @exception NullPointerException if <code>key</code> is <code>null</code>
* @exception MissingResourceException if no object for the given key can be found
* @exception ClassCastException if the object found for the given key is not a string
* @return the string for the given key
*/
public final String getString(String key) {
return (String) getObject(key);
}
/**
* Gets a string array for the given key from this resource bundle or one of its parents.
* Calling this method is equivalent to calling
* <blockquote>
* <code>(String[]) {@link #getObject(java.lang.String) getObject}(key)</code>.
* </blockquote>
*
* @param key the key for the desired string array
* @exception NullPointerException if <code>key</code> is <code>null</code>
* @exception MissingResourceException if no object for the given key can be found
* @exception ClassCastException if the object found for the given key is not a string array
* @return the string array for the given key
*/
public final String[] getStringArray(String key) {
return (String[]) getObject(key);
}
/**
* Gets an object for the given key from this resource bundle or one of its parents.
* This method first tries to obtain the object from this resource bundle using
* {@link #handleGetObject(java.lang.String) handleGetObject}.
* If not successful, and the parent resource bundle is not null,
* it calls the parent's <code>getObject</code> method.
* If still not successful, it throws a MissingResourceException.
*
* @param key the key for the desired object
* @exception NullPointerException if <code>key</code> is <code>null</code>
* @exception MissingResourceException if no object for the given key can be found
* @return the object for the given key
*/
public final Object getObject(String key) {
Object obj = handleGetObject(key);
if (obj == null) {
if (parent != null) {
obj = parent.getObject(key);
}
if (obj == null)
throw new MissingResourceException("Can't find resource for bundle "
+this.getClass().getName()
+", key "+key,
this.getClass().getName(),
key);
}
return obj;
}
/**
* Returns the locale of this resource bundle. This method can be used after a
* call to getBundle() to determine whether the resource bundle returned really
* corresponds to the requested locale or is a fallback.
*
* @return the locale of this resource bundle
*/
public Locale getLocale() {
return locale;
}
/**
* Sets the locale for this bundle. This is the locale that this
* bundle actually represents and does not depend on how the
* bundle was found by getBundle. Ex. if the user was looking
* for fr_FR and getBundle found en_US, the bundle's locale would
* be en_US, NOT fr_FR
* @param baseName the bundle's base name
* @param bundleName the complete bundle name including locale
* extension.
*/
private void setLocale(String baseName, String bundleName) {
if (baseName.length() == bundleName.length()) {
locale = new Locale("", "");
} else if (baseName.length() < bundleName.length()) {
int pos = baseName.length();
String temp = bundleName.substring(pos + 1);
pos = temp.indexOf('_');
if (pos == -1) {
locale = new Locale(temp, "", "");
return;
}
String language = temp.substring(0, pos);
temp = temp.substring(pos + 1);
pos = temp.indexOf('_');
if (pos == -1) {
locale = new Locale(language, temp, "");
return;
}
String country = temp.substring(0, pos);
temp = temp.substring(pos + 1);
locale = new Locale(language, country, temp);
} else {
//The base name is longer than the bundle name. Something is very wrong
//with the calling code.
throw new IllegalArgumentException();
}
}
/*
* Automatic determination of the ClassLoader to be used to load
* resources on behalf of the client. N.B. The client is getLoader's
* caller's caller.
*/
private static ClassLoader getLoader() {
Class[] stack = getClassContext();
/* Magic number 2 identifies our caller's caller */
Class c = stack[2];
ClassLoader cl = (c == null) ? null : c.getClassLoader();
if (cl == null) {
cl = ClassLoader.getSystemClassLoader();
}
return cl;
}
private static native Class[] getClassContext();
/**
* Sets the parent bundle of this bundle.
* The parent bundle is searched by {@link #getObject getObject}
* when this bundle does not contain a particular resource.
*
* @param parent this bundle's parent bundle.
*/
protected void setParent( ResourceBundle parent ) {
this.parent = parent;
}
/**
* Key used for cached resource bundles. The key checks
* the resource name, the class loader, and the default
* locale to determine if the resource is a match to the
* requested one. The loader may be null, but the
* searchName and the default locale must have a non-null value.
* Note that the default locale may change over time, and
* lookup should always be based on the current default
* locale (if at all).
*/
private static final class ResourceCacheKey implements Cloneable {
private LoaderReference loaderRef;
private String searchName;
private Locale defaultLocale;
private int hashCodeCache;
public boolean equals(Object other) {
if (this == other) {
return true;
}
try {
final ResourceCacheKey otherEntry = (ResourceCacheKey)other;
//quick check to see if they are not equal
if (hashCodeCache != otherEntry.hashCodeCache) {
return false;
}
//are the names the same?
if (!searchName.equals(otherEntry.searchName)) {
return false;
}
// are the default locales the same?
if (defaultLocale == null) {
if (otherEntry.defaultLocale != null) {
return false;
}
} else {
if (!defaultLocale.equals(otherEntry.defaultLocale)) {
return false;
}
}
//are refs (both non-null) or (both null)?
if (loaderRef == null) {
return otherEntry.loaderRef == null;
} else {
Object loaderRefValue = loaderRef.get();
return (otherEntry.loaderRef != null)
// with a null reference we can no longer find
// out which class loader was referenced; so
// treat it as unequal
&& (loaderRefValue != null)
&& (loaderRefValue == otherEntry.loaderRef.get());
}
} catch (NullPointerException e) {
return false;
} catch (ClassCastException e) {
return false;
}
}
public int hashCode() {
return hashCodeCache;
}
public Object clone() {
try {
ResourceCacheKey clone = (ResourceCacheKey) super.clone();
if (loaderRef != null) {
clone.loaderRef = new LoaderReference(loaderRef.get(), referenceQueue, clone);
}
return clone;
} catch (CloneNotSupportedException e) {
//this should never happen
throw new InternalError();
}
}
public void setKeyValues(ClassLoader loader, String searchName, Locale defaultLocale) {
this.searchName = searchName;
hashCodeCache = searchName.hashCode();
this.defaultLocale = defaultLocale;
if (defaultLocale != null) {
hashCodeCache ^= defaultLocale.hashCode();
}
if (loader == null) {
this.loaderRef = null;
} else {
loaderRef = new LoaderReference(loader, referenceQueue, this);
hashCodeCache ^= loader.hashCode();
}
}
public void clear() {
setKeyValues(null, "", null);
}
}
/**
* References to class loaders are weak references, so that they can be
* garbage collected when nobody else is using them. The ResourceBundle
* class has no reason to keep class loaders alive.
*/
private static final class LoaderReference extends WeakReference {
private ResourceCacheKey cacheKey;
LoaderReference(Object referent, ReferenceQueue q, ResourceCacheKey key) {
super(referent, q);
cacheKey = key;
}
ResourceCacheKey getCacheKey() {
return cacheKey;
}
}
/**
* Gets a resource bundle using the specified base name, the default locale,
* and the caller's class loader. Calling this method is equivalent to calling
* <blockquote>
* <code>getBundle(baseName, Locale.getDefault(), this.getClass().getClassLoader())</code>,
* </blockquote>
* except that <code>getClassLoader()</code> is run with the security
* privileges of <code>ResourceBundle</code>.
* See {@link #getBundle(java.lang.String, java.util.Locale, java.lang.ClassLoader) getBundle}
* for a complete description of the search and instantiation strategy.
*
* @param baseName the base name of the resource bundle, a fully qualified class name
* @exception java.lang.NullPointerException
* if <code>baseName</code> is <code>null</code>
* @exception MissingResourceException
* if no resource bundle for the specified base name can be found
* @return a resource bundle for the given base name and the default locale
*/
public static final ResourceBundle getBundle(String baseName)
{
return getBundleImpl(baseName, Locale.getDefault(),
/* must determine loader here, else we break stack invariant */
getLoader());
}
/**
* Gets a resource bundle using the specified base name and locale,
* and the caller's class loader. Calling this method is equivalent to calling
* <blockquote>
* <code>getBundle(baseName, locale, this.getClass().getClassLoader())</code>,
* </blockquote>
* except that <code>getClassLoader()</code> is run with the security
* privileges of <code>ResourceBundle</code>.
* See {@link #getBundle(java.lang.String, java.util.Locale, java.lang.ClassLoader) getBundle}
* for a complete description of the search and instantiation strategy.
*
* @param baseName the base name of the resource bundle, a fully qualified class name
* @param locale the locale for which a resource bundle is desired
* @exception java.lang.NullPointerException
* if <code>baseName</code> or <code>locale</code> is <code>null</code>
* @exception MissingResourceException
* if no resource bundle for the specified base name can be found
* @return a resource bundle for the given base name and locale
*/
public static final ResourceBundle getBundle(String baseName,
Locale locale)
{
return getBundleImpl(baseName, locale, getLoader());
}
/**
* Gets a resource bundle using the specified base name, locale, and class loader.
*
* <p>
* Conceptually, <code>getBundle</code> uses the following strategy for locating and instantiating
* resource bundles:
* <p>
* <code>getBundle</code> uses the base name, the specified locale, and the default
* locale (obtained from {@link java.util.Locale#getDefault() Locale.getDefault})
* to generate a sequence of <em>candidate bundle names</em>.
* If the specified locale's language, country, and variant are all empty
* strings, then the base name is the only candidate bundle name.
* Otherwise, the following sequence is generated from the attribute
* values of the specified locale (language1, country1, and variant1)
* and of the default locale (language2, country2, and variant2):
* <ul>
* <li> baseName + "_" + language1 + "_" + country1 + "_" + variant1
* <li> baseName + "_" + language1 + "_" + country1
* <li> baseName + "_" + language1
* <li> baseName + "_" + language2 + "_" + country2 + "_" + variant2
* <li> baseName + "_" + language2 + "_" + country2
* <li> baseName + "_" + language2
* <li> baseName
* </ul>
* <p>
* Candidate bundle names where the final component is an empty string are omitted.
* For example, if country1 is an empty string, the second candidate bundle name is omitted.
*
* <p>
* <code>getBundle</code> then iterates over the candidate bundle names to find the first
* one for which it can <em>instantiate</em> an actual resource bundle. For each candidate
* bundle name, it attempts to create a resource bundle:
* <ul>
* <li>
* First, it attempts to load a class using the candidate bundle name.
* If such a class can be found and loaded using the specified class loader, is assignment
* compatible with ResourceBundle, is accessible from ResourceBundle, and can be instantiated,
* <code>getBundle</code> creates a new instance of this class and uses it as the <em>result
* resource bundle</em>.
* <li>
* Otherwise, <code>getBundle</code> attempts to locate a property resource file.
* It generates a path name from the candidate bundle name by replacing all "." characters
* with "/" and appending the string ".properties".
* It attempts to find a "resource" with this name using
* {@link java.lang.ClassLoader#getResource(java.lang.String) ClassLoader.getResource}.
* (Note that a "resource" in the sense of <code>getResource</code> has nothing to do with
* the contents of a resource bundle, it is just a container of data, such as a file.)
* If it finds a "resource", it attempts to create a new
* {@link PropertyResourceBundle} instance from its contents.
* If successful, this instance becomes the <em>result resource bundle</em>.
* </ul>
*
* <p>
* If no result resource bundle has been found, a <code>MissingResourceException</code>
* is thrown.
*
* <p>
* Once a result resource bundle has been found, its parent chain is instantiated.
* <code>getBundle</code> iterates over the candidate bundle names that can be
* obtained by successively removing variant, country, and language
* (each time with the preceding "_") from the bundle name of the result resource bundle.
* As above, candidate bundle names where the final component is an empty string are omitted.
* With each of the candidate bundle names it attempts to instantiate a resource bundle, as
* described above.
* Whenever it succeeds, it calls the previously instantiated resource
* bundle's {@link #setParent(java.util.ResourceBundle) setParent} method
* with the new resource bundle, unless the previously instantiated resource
* bundle already has a non-null parent.
*
* <p>
* Implementations of <code>getBundle</code> may cache instantiated resource bundles
* and return the same resource bundle instance multiple times. They may also
* vary the sequence in which resource bundles are instantiated as long as the
* selection of the result resource bundle and its parent chain are compatible with
* the description above.
*
* <p>
* The <code>baseName</code> argument should be a fully qualified class name. However, for
* compatibility with earlier versions, Sun's Java 2 runtime environments do not verify this,
* and so it is possible to access <code>PropertyResourceBundle</code>s by specifying a
* path name (using "/") instead of a fully qualified class name (using ".").
*
* <p>
* <strong>Example:</strong> The following class and property files are provided:
* MyResources.class, MyResources_fr_CH.properties, MyResources_fr_CH.class,
* MyResources_fr.properties, MyResources_en.properties, MyResources_es_ES.class.
* The contents of all files are valid (that is, public non-abstract subclasses of ResourceBundle for
* the ".class" files, syntactically correct ".properties" files).
* The default locale is <code>Locale("en", "GB")</code>.
* <p>
* Calling <code>getBundle</code> with the shown locale argument values instantiates
* resource bundles from the following sources:
* <ul>
* <li>Locale("fr", "CH"): result MyResources_fr_CH.class, parent MyResources_fr.properties, parent MyResources.class
* <li>Locale("fr", "FR"): result MyResources_fr.properties, parent MyResources.class
* <li>Locale("de", "DE"): result MyResources_en.properties, parent MyResources.class
* <li>Locale("en", "US"): result MyResources_en.properties, parent MyResources.class
* <li>Locale("es", "ES"): result MyResources_es_ES.class, parent MyResources.class
* </ul>
* The file MyResources_fr_CH.properties is never used because it is hidden by
* MyResources_fr_CH.class.
*
* <p>
*
* @param baseName the base name of the resource bundle, a fully qualified class name
* @param locale the locale for which a resource bundle is desired
* @param loader the class loader from which to load the resource bundle
* @exception java.lang.NullPointerException
* if <code>baseName</code>, <code>locale</code>, or <code>loader</code> is <code>null</code>
* @exception MissingResourceException
* if no resource bundle for the specified base name can be found
* @return a resource bundle for the given base name and locale
* @since 1.2
*/
public static ResourceBundle getBundle(String baseName, Locale locale,
ClassLoader loader)
{
if (loader == null) {
throw new NullPointerException();
}
return getBundleImpl(baseName, locale, loader);
}
private static ResourceBundle getBundleImpl(String baseName, Locale locale,
ClassLoader loader)
{
if (baseName == null) {
throw new NullPointerException();
}
//fast path the case where the bundle is cached
String bundleName = baseName;
String localeSuffix = locale.toString();
if (localeSuffix.length() > 0) {
bundleName += "_" + localeSuffix;
} else if (locale.getVariant().length() > 0) {
//This corrects some strange behavior in Locale where
//new Locale("", "", "VARIANT").toString == ""
bundleName += "___" + locale.getVariant();
}
// The default locale may influence the lookup result, and
// it may change, so we get it here once.
Locale defaultLocale = Locale.getDefault();
Object lookup = findBundleInCache(loader, bundleName, defaultLocale);
if (lookup == NOT_FOUND) {
throwMissingResourceException(baseName, locale);
} else if (lookup != null) {
return (ResourceBundle)lookup;
}
//The bundle was not cached, so start doing lookup at the root
//Resources are loaded starting at the root and working toward
//the requested bundle.
//If findBundle returns null, we become responsible for defining
//the bundle, and must call putBundleInCache to complete this
//task. This is critical because other threads may be waiting
//for us to finish.
Object parent = NOT_FOUND;
try {
//locate the root bundle and work toward the desired child
Object root = findBundle(loader, baseName, defaultLocale, baseName, null);
if (root == null) {
putBundleInCache(loader, baseName, defaultLocale, NOT_FOUND);
root = NOT_FOUND;
}
// Search the main branch of the search tree.
// We need to keep references to the bundles we find on the main path
// so they don't get garbage collected before we get to propagate().
final Vector names = calculateBundleNames(baseName, locale);
Vector bundlesFound = new Vector(MAX_BUNDLES_SEARCHED);
// if we found the root bundle and no other bundle names are needed
// we can stop here. We don't need to search or load anything further.
boolean foundInMainBranch = (root != NOT_FOUND && names.size() == 0);
if (!foundInMainBranch) {
parent = root;
for (int i = 0; i < names.size(); i++) {
bundleName = (String)names.elementAt(i);
lookup = findBundle(loader, bundleName, defaultLocale, baseName, parent);
bundlesFound.addElement(lookup);
if (lookup != null) {
parent = lookup;
foundInMainBranch = true;
}
}
}
parent = root;
if (!foundInMainBranch) {
//we didn't find anything on the main branch, so we do the fallback branch
final Vector fallbackNames = calculateBundleNames(baseName, defaultLocale);
for (int i = 0; i < fallbackNames.size(); i++) {
bundleName = (String)fallbackNames.elementAt(i);
if (names.contains(bundleName)) {
//the fallback branch intersects the main branch so we can stop now.
break;
}
lookup = findBundle(loader, bundleName, defaultLocale, baseName, parent);
if (lookup != null) {
parent = lookup;
} else {
//propagate the parent to the child. We can do this
//here because we are in the default path.
putBundleInCache(loader, bundleName, defaultLocale, parent);
}
}
}
//propagate the inheritance/fallback down through the main branch
parent = propagate(loader, names, bundlesFound, defaultLocale, parent);
} catch (Exception e) {
//We should never get here unless there has been a change
//to the code that doesn't catch it's own exceptions.
cleanUpConstructionList();
throwMissingResourceException(baseName, locale);
} catch (Error e) {
//The only Error that can currently hit this code is a ThreadDeathError
//but errors might be added in the future, so we'll play it safe and
//clean up.
cleanUpConstructionList();
throw e;
}
if (parent == NOT_FOUND) {
throwMissingResourceException(baseName, locale);
}
return (ResourceBundle)parent;
}
/**
* propagate bundles from the root down the specified branch of the search tree.
* @param loader the class loader for the bundles
* @param names the names of the bundles along search path
* @param bundlesFound the bundles corresponding to the names (some may be null)
* @param defaultLocale the default locale at the time getBundle was called
* @param parent the parent of the first bundle in the path (the root bundle)
* @return the value of the last bundle along the path
*/
private static Object propagate(ClassLoader loader, Vector names,
Vector bundlesFound, Locale defaultLocale, Object parent) {
for (int i = 0; i < names.size(); i++) {
final String bundleName = (String)names.elementAt(i);
final Object lookup = bundlesFound.elementAt(i);
if (lookup == null) {
putBundleInCache(loader, bundleName, defaultLocale, parent);
} else {
parent = lookup;
}
}
return parent;
}
/** Throw a MissingResourceException with proper message */
private static void throwMissingResourceException(String baseName, Locale locale)
throws MissingResourceException{
throw new MissingResourceException("Can't find bundle for base name "
+ baseName + ", locale " + locale,
baseName + "_" + locale,"");
}
/**
* Remove any entries this thread may have in the construction list.
* This is done as cleanup in the case where a bundle can't be
* constructed.
*/
private static void cleanUpConstructionList() {
synchronized (cacheList) {
final Collection entries = underConstruction.values();
final Thread thisThread = Thread.currentThread();
while (entries.remove(thisThread)) {
}
}
}
/**
* Find a bundle in the cache or load it via the loader or a property file.
* If the bundle isn't found, an entry is put in the constructionCache
* and null is returned. If null is returned, the caller must define the bundle
* by calling putBundleInCache. This routine also propagates NOT_FOUND values
* from parent to child bundles when the parent is NOT_FOUND.
* @param loader the loader to use when loading a bundle
* @param bundleName the complete bundle name including locale extension
* @param defaultLocale the default locale at the time getBundle was called
* @param parent the parent of the resource bundle being loaded. null if
* the bundle is a root bundle
* @return the bundle or null if the bundle could not be found in the cache
* or loaded.
*/
private static Object findBundle(ClassLoader loader, String bundleName, Locale defaultLocale,
String baseName, Object parent) {
Object result;
synchronized (cacheList) {
// Before we do the real work of this method, see
// whether we need to do some housekeeping:
// If references to class loaders have been nulled out,
// remove all related information from the cache
Reference ref = referenceQueue.poll();
while (ref != null) {
cacheList.remove(((LoaderReference) ref).getCacheKey());
ref = referenceQueue.poll();
}
//check for bundle in cache
cacheKey.setKeyValues(loader, bundleName, defaultLocale);
result = cacheList.get(cacheKey);
if (result != null) {
cacheKey.clear();
return result;
}
// check to see if some other thread is building this bundle.
// Note that there is a rare chance that this thread is already
// working on this bundle, and in the process getBundle was called
// again, in which case we can't wait (4300693)
Thread builder = (Thread) underConstruction.get(cacheKey);
boolean beingBuilt = (builder != null && builder != Thread.currentThread());
//if some other thread is building the bundle...
if (beingBuilt) {
//while some other thread is building the bundle...
while (beingBuilt) {
cacheKey.clear();
try {
//Wait until the bundle is complete
cacheList.wait();
} catch (InterruptedException e) {
}
cacheKey.setKeyValues(loader, bundleName, defaultLocale);
beingBuilt = underConstruction.containsKey(cacheKey);
}
//if someone constructed the bundle for us, return it
result = cacheList.get(cacheKey);
if (result != null) {
cacheKey.clear();
return result;
}
}
//The bundle isn't in the cache, so we are now responsible for
//loading it and adding it to the cache.
final Object key = cacheKey.clone();
underConstruction.put(key, Thread.currentThread());
//the bundle is removed from the cache by putBundleInCache
cacheKey.clear();
}
//try loading the bundle via the class loader
result = loadBundle(loader, bundleName, defaultLocale);
if (result != null) {
// check whether we're still responsible for construction -
// a recursive call to getBundle might have handled it (4300693)
boolean constructing;
synchronized (cacheList) {
cacheKey.setKeyValues(loader, bundleName, defaultLocale);
constructing = underConstruction.get(cacheKey) == Thread.currentThread();
cacheKey.clear();
}
if (constructing) {
// set the bundle's parent and put it in the cache
final ResourceBundle bundle = (ResourceBundle)result;
if (parent != NOT_FOUND && bundle.parent == null) {
bundle.setParent((ResourceBundle) parent);
}
bundle.setLocale(baseName, bundleName);
putBundleInCache(loader, bundleName, defaultLocale, result);
}
}
return result;
}
/**
* Calculate the bundles along the search path from the base bundle to the
* bundle specified by baseName and locale.
* @param baseName the base bundle name
* @param locale the locale
* @param names the vector used to return the names of the bundles along
* the search path.
*
*/
private static Vector calculateBundleNames(String baseName, Locale locale) {
final Vector result = new Vector(MAX_BUNDLES_SEARCHED);
final String language = locale.getLanguage();
final int languageLength = language.length();
final String country = locale.getCountry();
final int countryLength = country.length();
final String variant = locale.getVariant();
final int variantLength = variant.length();
if (languageLength + countryLength + variantLength == 0) {
//The locale is "", "", "".
return result;
}
final StringBuffer temp = new StringBuffer(baseName);
temp.append('_');
temp.append(language);
if (languageLength > 0) {
result.addElement(temp.toString());
}
if (countryLength + variantLength == 0) {
return result;
}
temp.append('_');
temp.append(country);
if (countryLength > 0) {
result.addElement(temp.toString());
}
if (variantLength == 0) {
return result;
}
temp.append('_');
temp.append(variant);
result.addElement(temp.toString());
return result;
}
/**
* Find a bundle in the cache.
* @param loader the class loader that is responsible for loading the bundle.
* @param bundleName the complete name of the bundle including locale extension.
* ex. sun.text.resources.LocaleElements_fr_BE
* @param defaultLocale the default locale at the time getBundle was called
* @return the cached bundle. null if the bundle is not in the cache.
*/
private static Object findBundleInCache(ClassLoader loader, String bundleName,
Locale defaultLocale) {
//Synchronize access to cacheList, cacheKey, and underConstruction
synchronized (cacheList) {
cacheKey.setKeyValues(loader, bundleName, defaultLocale);
Object result = cacheList.get(cacheKey);
cacheKey.clear();
return result;
}
}
/**
* Put a new bundle in the cache and notify waiting threads that a new
* bundle has been put in the cache.
* @param defaultLocale the default locale at the time getBundle was called
*/
private static void putBundleInCache(ClassLoader loader, String bundleName,
Locale defaultLocale, Object value) {
//we use a static shared cacheKey but we use the lock in cacheList since
//the key is only used to interact with cacheList.
synchronized (cacheList) {
cacheKey.setKeyValues(loader, bundleName, defaultLocale);
cacheList.put(cacheKey.clone(), value);
underConstruction.remove(cacheKey);
cacheKey.clear();
//notify waiters that we're done constructing the bundle
cacheList.notifyAll();
}
}
/**
* Load a bundle through either the specified ClassLoader or from a ".properties" file
* and return the loaded bundle.
* @param loader the ClassLoader to use to load the bundle. If null, the system
* ClassLoader is used.
* @param bundleName the name of the resource to load. The name should be complete
* including a qualified class name followed by the locale extension.
* ex. sun.text.resources.LocaleElements_fr_BE
* @param defaultLocale the default locale at the time getBundle was called
* @return the bundle or null if none could be found.
*/
private static Object loadBundle(final ClassLoader loader, String bundleName, Locale defaultLocale) {
// replace any '/'s with '.'s for the bug-for-bug compatible
// ClassLoader behavior. (5077272, see also 4872868)
String correctedBundleName = bundleName.replace('/', '.');
// Search for class file using class loader
try {
Class bundleClass;
if (loader != null) {
bundleClass = loader.loadClass(correctedBundleName);
} else {
bundleClass = Class.forName(correctedBundleName);
}
if (ResourceBundle.class.isAssignableFrom(bundleClass)) {
Object myBundle = bundleClass.newInstance();
// Creating the instance may have triggered a recursive call to getBundle,
// in which case the bundle created by the recursive call would be in the
// cache now (4300693). For consistency, we'd then return the bundle from the cache.
Object otherBundle = findBundleInCache(loader, bundleName, defaultLocale);
if (otherBundle != null) {
return otherBundle;
} else {
return myBundle;
}
}
} catch (Exception e) {
} catch (LinkageError e) {
}
// Next search for a Properties file.
final String resName = bundleName.replace('.', '/') + ".properties";
InputStream stream = (InputStream)java.security.AccessController.doPrivileged(
new java.security.PrivilegedAction() {
public Object run() {
if (loader != null) {
return loader.getResourceAsStream(resName);
} else {
return ClassLoader.getSystemResourceAsStream(resName);
}
}
}
);
if (stream != null) {
// make sure it is buffered
stream = new java.io.BufferedInputStream(stream);
try {
return new PropertyResourceBundle(stream);
} catch (Exception e) {
} finally {
try {
stream.close();
} catch (Exception e) {
// to avoid propagating an IOException back into the caller
// (I'm assuming this is never going to happen, and if it does,
// I'm obeying the precedent of swallowing exceptions set by the
// existing code above)
}
}
}
return null;
}
/**
* Gets an object for the given key from this resource bundle.
* Returns null if this resource bundle does not contain an
* object for the given key.
*
* @param key the key for the desired object
* @exception NullPointerException if <code>key</code> is <code>null</code>
* @return the object for the given key, or null
*/
protected abstract Object handleGetObject(String key);
/**
* Returns an enumeration of the keys.
*
*/
public abstract Enumeration getKeys();
}