/*
* Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 in the LICENSE file that
* accompanied this code).
*
* 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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/*
* (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.IOException;
import java.io.InputStream;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import java.lang.ref.WeakReference;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.jar.JarEntry;
/**
*
* 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 {
* protected Object[][] getContents() {
* return new Object[][] {
* // LOCALIZE THE SECOND STRING OF EACH ARRAY (e.g., "OK")
* {"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>, <code>ResourceBundle</code> 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 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>.
*
* <h4>ResourceBundle.Control</h4>
*
* The {@link ResourceBundle.Control} class provides information necessary
* to perform the bundle loading process by the <code>getBundle</code>
* factory methods that take a <code>ResourceBundle.Control</code>
* instance. You can implement your own subclass in order to enable
* non-standard resource bundle formats, change the search strategy, or
* define caching parameters. Refer to the descriptions of the class and the
* {@link #getBundle(String, Locale, ClassLoader, Control) getBundle}
* factory method for details.
*
* <h4>Cache Management</h4>
*
* Resource bundle instances created by the <code>getBundle</code> factory
* methods are cached by default, and the factory methods return the same
* resource bundle instance multiple times if it has been
* cached. <code>getBundle</code> clients may clear the cache, manage the
* lifetime of cached resource bundle instances using time-to-live values,
* or specify not to cache resource bundle instances. Refer to the
* descriptions of the {@linkplain #getBundle(String, Locale, ClassLoader,
* Control) <code>getBundle</code> factory method}, {@link
* #clearCache(ClassLoader) clearCache}, {@link
* Control#getTimeToLive(String, Locale)
* ResourceBundle.Control.getTimeToLive}, and {@link
* Control#needsReload(String, Locale, String, ClassLoader, ResourceBundle,
* long) ResourceBundle.Control.needsReload} for details.
*
* <h4>Example</h4>
*
* The following is a very simple example of a <code>ResourceBundle</code>
* subclass, <code>MyResources</code>, that manages two resources (for a larger number of
* resources you would probably use a <code>Map</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).
* <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;
* }
*
* public Enumeration<String> getKeys() {
* return Collections.enumeration(keySet());
* }
*
* // Overrides handleKeySet() so that the getKeys() implementation
* // can rely on the keySet() value.
* protected Set<String> handleKeySet() {
* return new HashSet<String>(Arrays.asList("okKey", "cancelKey"));
* }
* }
*
* // 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;
* }
*
* protected Set<String> handleKeySet() {
* return new HashSet<String>(Arrays.asList("cancelKey"));
* }
* }
* </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
*/
public abstract class ResourceBundle {
/** initial size of the bundle cache */
private static final int INITIAL_CACHE_SIZE = 32;
/** constant indicating that no resource bundle exists */
private static final ResourceBundle NONEXISTENT_BUNDLE = new ResourceBundle() {
public Enumeration<String> getKeys() { return null; }
protected Object handleGetObject(String key) { return null; }
public String toString() { return "NONEXISTENT_BUNDLE"; }
};
/**
* The cache is a map from cache keys (with bundle base name, locale, and
* class loader) to either a resource bundle or NONEXISTENT_BUNDLE wrapped by a
* BundleReference.
*
* The cache is a ConcurrentMap, allowing the cache to be searched
* concurrently by multiple threads. 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 final ConcurrentMap<CacheKey, BundleReference> cacheList
= new ConcurrentHashMap<CacheKey, BundleReference>(INITIAL_CACHE_SIZE);
/**
* This ConcurrentMap 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 findBundleInCache and putBundleInCache.
*/
private static final ConcurrentMap<CacheKey, Thread> underConstruction
= new ConcurrentHashMap<CacheKey, Thread>();
/**
* Queue for reference objects referring to class loaders or bundles.
*/
private static final 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;
/**
* The base bundle name for this bundle.
*/
private String name;
/**
* The flag indicating this bundle has expired in the cache.
*/
private volatile boolean expired;
/**
* The back link to the cache key. null if this bundle isn't in
* the cache (yet) or has expired.
*/
private volatile CacheKey cacheKey;
/**
* A Set of the keys contained only in this ResourceBundle.
*/
private volatile Set<String> keySet;
/**
* 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;
}
/*
* 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) {
// When the caller's loader is the boot class loader, cl is null
// here. In that case, ClassLoader.getSystemClassLoader() may
// return the same class loader that the application is
// using. We therefore use a wrapper ClassLoader to create a
// separate scope for bundles loaded on behalf of the Java
// runtime so that these bundles cannot be returned from the
// cache to the application (5048280).
cl = RBClassLoader.INSTANCE;
}
return cl;
}
private static native Class[] getClassContext();
/**
* A wrapper of ClassLoader.getSystemClassLoader().
*/
private static class RBClassLoader extends ClassLoader {
private static final RBClassLoader INSTANCE = AccessController.doPrivileged(
new PrivilegedAction<RBClassLoader>() {
public RBClassLoader run() {
return new RBClassLoader();
}
});
private static final ClassLoader loader = ClassLoader.getSystemClassLoader();
private RBClassLoader() {
}
public Class<?> loadClass(String name) throws ClassNotFoundException {
if (loader != null) {
return loader.loadClass(name);
}
return Class.forName(name);
}
public URL getResource(String name) {
if (loader != null) {
return loader.getResource(name);
}
return ClassLoader.getSystemResource(name);
}
public InputStream getResourceAsStream(String name) {
if (loader != null) {
return loader.getResourceAsStream(name);
}
return ClassLoader.getSystemResourceAsStream(name);
}
}
/**
* 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) {
assert parent != NONEXISTENT_BUNDLE;
this.parent = parent;
}
/**
* Key used for cached resource bundles. The key checks the base
* name, the locale, and the class loader to determine if the
* resource is a match to the requested one. The loader may be
* null, but the base name and the locale must have a non-null
* value.
*/
private static final class CacheKey implements Cloneable {
// These three are the actual keys for lookup in Map.
private String name;
private Locale locale;
private LoaderReference loaderRef;
// bundle format which is necessary for calling
// Control.needsReload().
private String format;
// These time values are in CacheKey so that NONEXISTENT_BUNDLE
// doesn't need to be cloned for caching.
// The time when the bundle has been loaded
private volatile long loadTime;
// The time when the bundle expires in the cache, or either
// Control.TTL_DONT_CACHE or Control.TTL_NO_EXPIRATION_CONTROL.
private volatile long expirationTime;
// Placeholder for an error report by a Throwable
private Throwable cause;
// Hash code value cache to avoid recalculating the hash code
// of this instance.
private int hashCodeCache;
CacheKey(String baseName, Locale locale, ClassLoader loader) {
this.name = baseName;
this.locale = locale;
if (loader == null) {
this.loaderRef = null;
} else {
loaderRef = new LoaderReference(loader, referenceQueue, this);
}
calculateHashCode();
}
String getName() {
return name;
}
CacheKey setName(String baseName) {
if (!this.name.equals(baseName)) {
this.name = baseName;
calculateHashCode();
}
return this;
}
Locale getLocale() {
return locale;
}
CacheKey setLocale(Locale locale) {
if (!this.locale.equals(locale)) {
this.locale = locale;
calculateHashCode();
}
return this;
}
ClassLoader getLoader() {
return (loaderRef != null) ? loaderRef.get() : null;
}
public boolean equals(Object other) {
if (this == other) {
return true;
}
try {
final CacheKey otherEntry = (CacheKey)other;
//quick check to see if they are not equal
if (hashCodeCache != otherEntry.hashCodeCache) {
return false;
}
//are the names the same?
if (!name.equals(otherEntry.name)) {
return false;
}
// are the locales the same?
if (!locale.equals(otherEntry.locale)) {
return false;
}
//are refs (both non-null) or (both null)?
if (loaderRef == null) {
return otherEntry.loaderRef == null;
}
ClassLoader loader = 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
&& (loader != null)
&& (loader == otherEntry.loaderRef.get());
} catch (NullPointerException e) {
} catch (ClassCastException e) {
}
return false;
}
public int hashCode() {
return hashCodeCache;
}
private void calculateHashCode() {
hashCodeCache = name.hashCode() << 3;
hashCodeCache ^= locale.hashCode();
ClassLoader loader = getLoader();
if (loader != null) {
hashCodeCache ^= loader.hashCode();
}
}
public Object clone() {
try {
CacheKey clone = (CacheKey) super.clone();
if (loaderRef != null) {
clone.loaderRef = new LoaderReference(loaderRef.get(),
referenceQueue, clone);
}
// Clear the reference to a Throwable
clone.cause = null;
return clone;
} catch (CloneNotSupportedException e) {
//this should never happen
throw new InternalError();
}
}
String getFormat() {
return format;
}
void setFormat(String format) {
this.format = format;
}
private void setCause(Throwable cause) {
if (this.cause == null) {
this.cause = cause;
} else {
// Override the cause if the previous one is
// ClassNotFoundException.
if (this.cause instanceof ClassNotFoundException) {
this.cause = cause;
}
}
}
private Throwable getCause() {
return cause;
}
public String toString() {
String l = locale.toString();
if (l.length() == 0) {
if (locale.getVariant().length() != 0) {
l = "__" + locale.getVariant();
} else {
l = "\"\"";
}
}
return "CacheKey[" + name + ", lc=" + l + ", ldr=" + getLoader()
+ "(format=" + format + ")]";
}
}
/**
* The common interface to get a CacheKey in LoaderReference and
* BundleReference.
*/
private static interface CacheKeyReference {
public CacheKey getCacheKey();
}
/**
* 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<ClassLoader>
implements CacheKeyReference {
private CacheKey cacheKey;
LoaderReference(ClassLoader referent, ReferenceQueue q, CacheKey key) {
super(referent, q);
cacheKey = key;
}
public CacheKey getCacheKey() {
return cacheKey;
}
}
/**
* References to bundles are soft references so that they can be garbage
* collected when they have no hard references.
*/
private static final class BundleReference extends SoftReference<ResourceBundle>
implements CacheKeyReference {
private CacheKey cacheKey;
BundleReference(ResourceBundle referent, ReferenceQueue q, CacheKey key) {
super(referent, q);
cacheKey = key;
}
public CacheKey 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(String, Locale, 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(),
Control.INSTANCE);
}
/**
* Returns a resource bundle using the specified base name, the
* default locale and the specified control. Calling this method
* is equivalent to calling
* <pre>
* getBundle(baseName, Locale.getDefault(),
* this.getClass().getClassLoader(), control),
* </pre>
* except that <code>getClassLoader()</code> is run with the security
* privileges of <code>ResourceBundle</code>. See {@link
* #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
* complete description of the resource bundle loading process with a
* <code>ResourceBundle.Control</code>.
*
* @param baseName
* the base name of the resource bundle, a fully qualified class
* name
* @param control
* the control which gives information for the resource bundle
* loading process
* @return a resource bundle for the given base name and the default
* locale
* @exception NullPointerException
* if <code>baseName</code> or <code>control</code> is
* <code>null</code>
* @exception MissingResourceException
* if no resource bundle for the specified base name can be found
* @exception IllegalArgumentException
* if the given <code>control</code> doesn't perform properly
* (e.g., <code>control.getCandidateLocales</code> returns null.)
* Note that validation of <code>control</code> is performed as
* needed.
* @since 1.6
*/
public static final ResourceBundle getBundle(String baseName,
Control control) {
return getBundleImpl(baseName, Locale.getDefault(),
/* must determine loader here, else we break stack invariant */
getLoader(),
control);
}
/**
* 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(String, Locale, 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 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,
/* must determine loader here, else we break stack invariant */
getLoader(),
Control.INSTANCE);
}
/**
* Returns a resource bundle using the specified base name, target
* locale and control, and the caller's class loader. Calling this
* method is equivalent to calling
* <pre>
* getBundle(baseName, targetLocale, this.getClass().getClassLoader(),
* control),
* </pre>
* except that <code>getClassLoader()</code> is run with the security
* privileges of <code>ResourceBundle</code>. See {@link
* #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
* complete description of the resource bundle loading process with a
* <code>ResourceBundle.Control</code>.
*
* @param baseName
* the base name of the resource bundle, a fully qualified
* class name
* @param targetLocale
* the locale for which a resource bundle is desired
* @param control
* the control which gives information for the resource
* bundle loading process
* @return a resource bundle for the given base name and a
* <code>Locale</code> in <code>locales</code>
* @exception NullPointerException
* if <code>baseName</code>, <code>locales</code> or
* <code>control</code> is <code>null</code>
* @exception MissingResourceException
* if no resource bundle for the specified base name in any
* of the <code>locales</code> can be found.
* @exception IllegalArgumentException
* if the given <code>control</code> doesn't perform properly
* (e.g., <code>control.getCandidateLocales</code> returns null.)
* Note that validation of <code>control</code> is performed as
* needed.
* @since 1.6
*/
public static final ResourceBundle getBundle(String baseName, Locale targetLocale,
Control control) {
return getBundleImpl(baseName, targetLocale,
/* must determine loader here, else we break stack invariant */
getLoader(),
control);
}
/**
* Gets a resource bundle using the specified base name, locale, and class loader.
*
* <p><a name="default_behavior"/>
* 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 <a name="candidates"><em>candidate bundle names</em></a>.
* 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><a name="parent_chain"/>
* Once a result resource bundle has been found, its <em>parent chain</em> 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>
* <code>getBundle</code> caches instantiated resource bundles and
* may return the same resource bundle instance multiple
* times.
*
* <p>
* The <code>baseName</code> argument should be a fully qualified class name. However, for
* compatibility with earlier versions, Sun's Java SE 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><a name="default_behavior_example"/>
* <strong>Example:</strong><br>The following class and property files are provided:
* <pre>
* MyResources.class
* MyResources.properties
* MyResources_fr.properties
* MyResources_fr_CH.class
* MyResources_fr_CH.properties
* MyResources_en.properties
* MyResources_es_ES.class
* </pre>
* The contents of all files are valid (that is, public non-abstract subclasses of <code>ResourceBundle</code> 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>
* <p>The file MyResources_fr_CH.properties is never used because it is hidden by
* MyResources_fr_CH.class. Likewise, MyResources.properties is also hidden by
* MyResources.class.
*
* @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
* @return a resource bundle for the given base name and locale
* @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
* @since 1.2
*/
public static ResourceBundle getBundle(String baseName, Locale locale,
ClassLoader loader)
{
if (loader == null) {
throw new NullPointerException();
}
return getBundleImpl(baseName, locale, loader, Control.INSTANCE);
}
/**
* Returns a resource bundle using the specified base name, target
* locale, class loader and control. Unlike the {@linkplain
* #getBundle(String, Locale, ClassLoader) <code>getBundle</code>
* factory methods with no <code>control</code> argument}, the given
* <code>control</code> specifies how to locate and instantiate resource
* bundles. Conceptually, the bundle loading process with the given
* <code>control</code> is performed in the following steps.
*
* <p>
* <ol>
* <li>This factory method looks up the resource bundle in the cache for
* the specified <code>baseName</code>, <code>targetLocale</code> and
* <code>loader</code>. If the requested resource bundle instance is
* found in the cache and the time-to-live periods of the instance and
* all of its parent instances have not expired, the instance is returned
* to the caller. Otherwise, this factory method proceeds with the
* loading process below.</li>
*
* <li>The {@link ResourceBundle.Control#getFormats(String)
* control.getFormats} method is called to get resource bundle formats
* to produce bundle or resource names. The strings
* <code>"java.class"</code> and <code>"java.properties"</code>
* designate class-based and {@linkplain PropertyResourceBundle
* property}-based resource bundles, respectively. Other strings
* starting with <code>"java."</code> are reserved for future extensions
* and must not be used for application-defined formats. Other strings
* designate application-defined formats.</li>
*
* <li>The {@link ResourceBundle.Control#getCandidateLocales(String,
* Locale) control.getCandidateLocales} method is called with the target
* locale to get a list of <em>candidate <code>Locale</code>s</em> for
* which resource bundles are searched.</li>
*
* <li>The {@link ResourceBundle.Control#newBundle(String, Locale,
* String, ClassLoader, boolean) control.newBundle} method is called to
* instantiate a <code>ResourceBundle</code> for the base bundle name, a
* candidate locale, and a format. (Refer to the note on the cache
* lookup below.) This step is iterated over all combinations of the
* candidate locales and formats until the <code>newBundle</code> method
* returns a <code>ResourceBundle</code> instance or the iteration has
* used up all the combinations. For example, if the candidate locales
* are <code>Locale("de", "DE")</code>, <code>Locale("de")</code> and
* <code>Locale("")</code> and the formats are <code>"java.class"</code>
* and <code>"java.properties"</code>, then the following is the
* sequence of locale-format combinations to be used to call
* <code>control.newBundle</code>.
*
* <table style="width: 50%; text-align: left; margin-left: 40px;"
* border="0" cellpadding="2" cellspacing="2">
* <tbody><code>
* <tr>
* <td
* style="vertical-align: top; text-align: left; font-weight: bold; width: 50%;">Locale<br>
* </td>
* <td
* style="vertical-align: top; text-align: left; font-weight: bold; width: 50%;">format<br>
* </td>
* </tr>
* <tr>
* <td style="vertical-align: top; width: 50%;">Locale("de", "DE")<br>
* </td>
* <td style="vertical-align: top; width: 50%;">java.class<br>
* </td>
* </tr>
* <tr>
* <td style="vertical-align: top; width: 50%;">Locale("de", "DE")</td>
* <td style="vertical-align: top; width: 50%;">java.properties<br>
* </td>
* </tr>
* <tr>
* <td style="vertical-align: top; width: 50%;">Locale("de")</td>
* <td style="vertical-align: top; width: 50%;">java.class</td>
* </tr>
* <tr>
* <td style="vertical-align: top; width: 50%;">Locale("de")</td>
* <td style="vertical-align: top; width: 50%;">java.properties</td>
* </tr>
* <tr>
* <td style="vertical-align: top; width: 50%;">Locale("")<br>
* </td>
* <td style="vertical-align: top; width: 50%;">java.class</td>
* </tr>
* <tr>
* <td style="vertical-align: top; width: 50%;">Locale("")</td>
* <td style="vertical-align: top; width: 50%;">java.properties</td>
* </tr>
* </code></tbody>
* </table>
* </li>
*
* <li>If the previous step has found no resource bundle, proceed to
* Step 6. If a bundle has been found that is a base bundle (a bundle
* for <code>Locale("")</code>), and the candidate locale list only contained
* <code>Locale("")</code>, return the bundle to the caller. If a bundle
* has been found that is a base bundle, but the candidate locale list
* contained locales other than Locale(""), put the bundle on hold and
* proceed to Step 6. If a bundle has been found that is not a base
* bundle, proceed to Step 7.</li>
*
* <li>The {@link ResourceBundle.Control#getFallbackLocale(String,
* Locale) control.getFallbackLocale} method is called to get a fallback
* locale (alternative to the current target locale) to try further
* finding a resource bundle. If the method returns a non-null locale,
* it becomes the next target locale and the loading process starts over
* from Step 3. Otherwise, if a base bundle was found and put on hold in
* a previous Step 5, it is returned to the caller now. Otherwise, a
* MissingResourceException is thrown.</li>
*
* <li>At this point, we have found a resource bundle that's not the
* base bundle. If this bundle set its parent during its instantiation,
* it is returned to the caller. Otherwise, its <a
* href="./ResourceBundle.html#parent_chain">parent chain</a> is
* instantiated based on the list of candidate locales from which it was
* found. Finally, the bundle is returned to the caller.</li>
*
*
* </ol>
*
* <p>During the resource bundle loading process above, this factory
* method looks up the cache before calling the {@link
* Control#newBundle(String, Locale, String, ClassLoader, boolean)
* control.newBundle} method. If the time-to-live period of the
* resource bundle found in the cache has expired, the factory method
* calls the {@link ResourceBundle.Control#needsReload(String, Locale,
* String, ClassLoader, ResourceBundle, long) control.needsReload}
* method to determine whether the resource bundle needs to be reloaded.
* If reloading is required, the factory method calls
* <code>control.newBundle</code> to reload the resource bundle. If
* <code>control.newBundle</code> returns <code>null</code>, the factory
* method puts a dummy resource bundle in the cache as a mark of
* nonexistent resource bundles in order to avoid lookup overhead for
* subsequent requests. Such dummy resource bundles are under the same
* expiration control as specified by <code>control</code>.
*
* <p>All resource bundles loaded are cached by default. Refer to
* {@link Control#getTimeToLive(String,Locale)
* control.getTimeToLive} for details.
*
*
* <p>The following is an example of the bundle loading process with the
* default <code>ResourceBundle.Control</code> implementation.
*
* <p>Conditions:
* <ul>
* <li>Base bundle name: <code>foo.bar.Messages</code>
* <li>Requested <code>Locale</code>: {@link Locale#ITALY}</li>
* <li>Default <code>Locale</code>: {@link Locale#FRENCH}</li>
* <li>Available resource bundles:
* <code>foo/bar/Messages_fr.properties</code> and
* <code>foo/bar/Messages.properties</code></li>
*
* </ul>
*
* <p>First, <code>getBundle</code> tries loading a resource bundle in
* the following sequence.
*
* <ul>
* <li>class <code>foo.bar.Messages_it_IT</code>
* <li>file <code>foo/bar/Messages_it_IT.properties</code>
* <li>class <code>foo.bar.Messages_it</code></li>
* <li>file <code>foo/bar/Messages_it.properties</code></li>
* <li>class <code>foo.bar.Messages</code></li>
* <li>file <code>foo/bar/Messages.properties</code></li>
* </ul>
*
* <p>At this point, <code>getBundle</code> finds
* <code>foo/bar/Messages.properties</code>, which is put on hold
* because it's the base bundle. <code>getBundle</code> calls {@link
* Control#getFallbackLocale(String, Locale)
* control.getFallbackLocale("foo.bar.Messages", Locale.ITALY)} which
* returns <code>Locale.FRENCH</code>. Next, <code>getBundle</code>
* tries loading a bundle in the following sequence.
*
* <ul>
* <li>class <code>foo.bar.Messages_fr</code></li>
* <li>file <code>foo/bar/Messages_fr.properties</code></li>
* <li>class <code>foo.bar.Messages</code></li>
* <li>file <code>foo/bar/Messages.properties</code></li>
* </ul>
*
* <p><code>getBundle</code> finds
* <code>foo/bar/Messages_fr.properties</code> and creates a
* <code>ResourceBundle</code> instance. Then, <code>getBundle</code>
* sets up its parent chain from the list of the candiate locales. Only
* <code>foo/bar/Messages.properties</code> is found in the list and
* <code>getBundle</code> creates a <code>ResourceBundle</code> instance
* that becomes the parent of the instance for
* <code>foo/bar/Messages_fr.properties</code>.
*
* @param baseName
* the base name of the resource bundle, a fully qualified
* class name
* @param targetLocale
* the locale for which a resource bundle is desired
* @param loader
* the class loader from which to load the resource bundle
* @param control
* the control which gives information for the resource
* bundle loading process
* @return a resource bundle for the given base name and locale
* @exception NullPointerException
* if <code>baseName</code>, <code>targetLocale</code>,
* <code>loader</code>, or <code>control</code> is
* <code>null</code>
* @exception MissingResourceException
* if no resource bundle for the specified base name can be found
* @exception IllegalArgumentException
* if the given <code>control</code> doesn't perform properly
* (e.g., <code>control.getCandidateLocales</code> returns null.)
* Note that validation of <code>control</code> is performed as
* needed.
* @since 1.6
*/
public static ResourceBundle getBundle(String baseName, Locale targetLocale,
ClassLoader loader, Control control) {
if (loader == null || control == null) {
throw new NullPointerException();
}
return getBundleImpl(baseName, targetLocale, loader, control);
}
private static ResourceBundle getBundleImpl(String baseName, Locale locale,
ClassLoader loader, Control control) {
if (locale == null || control == null) {
throw new NullPointerException();
}
// We create a CacheKey here for use by this call. The base
// name and loader will never change during the bundle loading
// process. We have to make sure that the locale is set before
// using it as a cache key.
CacheKey cacheKey = new CacheKey(baseName, locale, loader);
ResourceBundle bundle = null;
// Quick lookup of the cache.
BundleReference bundleRef = cacheList.get(cacheKey);
if (bundleRef != null) {
bundle = bundleRef.get();
bundleRef = null;
}
// If this bundle and all of its parents are valid (not expired),
// then return this bundle. If any of the bundles is expired, we
// don't call control.needsReload here but instead drop into the
// complete loading process below.
if (isValidBundle(bundle) && hasValidParentChain(bundle)) {
return bundle;
}
// No valid bundle was found in the cache, so we need to load the
// resource bundle and its parents.
boolean isKnownControl = (control == Control.INSTANCE) ||
(control instanceof SingleFormatControl);
List<String> formats = control.getFormats(baseName);
if (!isKnownControl && !checkList(formats)) {
throw new IllegalArgumentException("Invalid Control: getFormats");
}
ResourceBundle baseBundle = null;
for (Locale targetLocale = locale;
targetLocale != null;
targetLocale = control.getFallbackLocale(baseName, targetLocale)) {
List<Locale> candidateLocales = control.getCandidateLocales(baseName, targetLocale);
if (!isKnownControl && !checkList(candidateLocales)) {
throw new IllegalArgumentException("Invalid Control: getCandidateLocales");
}
bundle = findBundle(cacheKey, candidateLocales, formats, 0, control, baseBundle);
// If the loaded bundle is the base bundle and exactly for the
// requested locale or the only candidate locale, then take the
// bundle as the resulting one. If the loaded bundle is the base
// bundle, it's put on hold until we finish processing all
// fallback locales.
if (isValidBundle(bundle)) {
boolean isBaseBundle = Locale.ROOT.equals(bundle.locale);
if (!isBaseBundle || bundle.locale.equals(locale)
|| (candidateLocales.size() == 1
&& bundle.locale.equals(candidateLocales.get(0)))) {
break;
}
// If the base bundle has been loaded, keep the reference in
// baseBundle so that we can avoid any redundant loading in case
// the control specify not to cache bundles.
if (isBaseBundle && baseBundle == null) {
baseBundle = bundle;
}
}
}
if (bundle == null) {
if (baseBundle == null) {
throwMissingResourceException(baseName, locale, cacheKey.getCause());
}
bundle = baseBundle;
}
return bundle;
}
/**
* Checks if the given <code>List</code> is not null, not empty,
* not having null in its elements.
*/
private static final boolean checkList(List a) {
boolean valid = (a != null && a.size() != 0);
if (valid) {
int size = a.size();
for (int i = 0; valid && i < size; i++) {
valid = (a.get(i) != null);
}
}
return valid;
}
private static final ResourceBundle findBundle(CacheKey cacheKey,
List<Locale> candidateLocales,
List<String> formats,
int index,
Control control,
ResourceBundle baseBundle) {
Locale targetLocale = candidateLocales.get(index);
ResourceBundle parent = null;
if (index != candidateLocales.size() - 1) {
parent = findBundle(cacheKey, candidateLocales, formats, index + 1,
control, baseBundle);
} else if (baseBundle != null && Locale.ROOT.equals(targetLocale)) {
return baseBundle;
}
// Before we do the real loading work, see whether we need to
// do some housekeeping: If references to class loaders or
// resource bundles have been nulled out, remove all related
// information from the cache.
Object ref;
while ((ref = referenceQueue.poll()) != null) {
cacheList.remove(((CacheKeyReference)ref).getCacheKey());
}
// flag indicating the resource bundle has expired in the cache
boolean expiredBundle = false;
// First, look up the cache to see if it's in the cache, without
// declaring beginLoading.
cacheKey.setLocale(targetLocale);
ResourceBundle bundle = findBundleInCache(cacheKey, control);
if (isValidBundle(bundle)) {
expiredBundle = bundle.expired;
if (!expiredBundle) {
// If its parent is the one asked for by the candidate
// locales (the runtime lookup path), we can take the cached
// one. (If it's not identical, then we'd have to check the
// parent's parents to be consistent with what's been
// requested.)
if (bundle.parent == parent) {
return bundle;
}
// Otherwise, remove the cached one since we can't keep
// the same bundles having different parents.
BundleReference bundleRef = cacheList.get(cacheKey);
if (bundleRef != null && bundleRef.get() == bundle) {
cacheList.remove(cacheKey, bundleRef);
}
}
}
if (bundle != NONEXISTENT_BUNDLE) {
CacheKey constKey = (CacheKey) cacheKey.clone();
try {
// Try declaring loading. If beginLoading() returns true,
// then we can proceed. Otherwise, we need to take a look
// at the cache again to see if someone else has loaded
// the bundle and put it in the cache while we've been
// waiting for other loading work to complete.
while (!beginLoading(constKey)) {
bundle = findBundleInCache(cacheKey, control);
if (bundle == null) {
continue;
}
if (bundle == NONEXISTENT_BUNDLE) {
// If the bundle is NONEXISTENT_BUNDLE, the bundle doesn't exist.
return parent;
}
expiredBundle = bundle.expired;
if (!expiredBundle) {
if (bundle.parent == parent) {
return bundle;
}
BundleReference bundleRef = cacheList.get(cacheKey);
if (bundleRef != null && bundleRef.get() == bundle) {
cacheList.remove(cacheKey, bundleRef);
}
}
}
try {
bundle = loadBundle(cacheKey, formats, control, expiredBundle);
if (bundle != null) {
if (bundle.parent == null) {
bundle.setParent(parent);
}
bundle.locale = targetLocale;
bundle = putBundleInCache(cacheKey, bundle, control);
return bundle;
}
// Put NONEXISTENT_BUNDLE in the cache as a mark that there's no bundle
// instance for the locale.
putBundleInCache(cacheKey, NONEXISTENT_BUNDLE, control);
} finally {
endLoading(constKey);
}
} finally {
if (constKey.getCause() instanceof InterruptedException) {
Thread.currentThread().interrupt();
}
}
}
assert underConstruction.get(cacheKey) != Thread.currentThread();
return parent;
}
private static final ResourceBundle loadBundle(CacheKey cacheKey,
List<String> formats,
Control control,
boolean reload) {
assert underConstruction.get(cacheKey) == Thread.currentThread();
// Here we actually load the bundle in the order of formats
// specified by the getFormats() value.
Locale targetLocale = cacheKey.getLocale();
ResourceBundle bundle = null;
int size = formats.size();
for (int i = 0; i < size; i++) {
String format = formats.get(i);
try {
bundle = control.newBundle(cacheKey.getName(), targetLocale, format,
cacheKey.getLoader(), reload);
} catch (LinkageError error) {
// We need to handle the LinkageError case due to
// inconsistent case-sensitivity in ClassLoader.
// See 6572242 for details.
cacheKey.setCause(error);
} catch (Exception cause) {
cacheKey.setCause(cause);
}
if (bundle != null) {
// Set the format in the cache key so that it can be
// used when calling needsReload later.
cacheKey.setFormat(format);
bundle.name = cacheKey.getName();
bundle.locale = targetLocale;
// Bundle provider might reuse instances. So we should make
// sure to clear the expired flag here.
bundle.expired = false;
break;
}
}
assert underConstruction.get(cacheKey) == Thread.currentThread();
return bundle;
}
private static final boolean isValidBundle(ResourceBundle bundle) {
return bundle != null && bundle != NONEXISTENT_BUNDLE;
}
/**
* Determines whether any of resource bundles in the parent chain,
* including the leaf, have expired.
*/
private static final boolean hasValidParentChain(ResourceBundle bundle) {
long now = System.currentTimeMillis();
while (bundle != null) {
if (bundle.expired) {
return false;
}
CacheKey key = bundle.cacheKey;
if (key != null) {
long expirationTime = key.expirationTime;
if (expirationTime >= 0 && expirationTime <= now) {
return false;
}
}
bundle = bundle.parent;
}
return true;
}
/**
* Declares the beginning of actual resource bundle loading. This method
* returns true if the declaration is successful and the current thread has
* been put in underConstruction. If someone else has already begun
* loading, this method waits until that loading work is complete and
* returns false.
*/
private static final boolean beginLoading(CacheKey constKey) {
Thread me = Thread.currentThread();
Thread worker;
// We need to declare by putting the current Thread (me) to
// underConstruction that we are working on loading the specified
// resource bundle. If we are already working the loading, it means
// that the resource loading requires a recursive call. In that case,
// we have to proceed. (4300693)
if (((worker = underConstruction.putIfAbsent(constKey, me)) == null)
|| worker == me) {
return true;
}
// If someone else is working on the loading, wait until
// the Thread finishes the bundle loading.
synchronized (worker) {
while (underConstruction.get(constKey) == worker) {
try {
worker.wait();
} catch (InterruptedException e) {
// record the interruption
constKey.setCause(e);
}
}
}
return false;
}
/**
* Declares the end of the bundle loading. This method calls notifyAll
* for those who are waiting for this completion.
*/
private static final void endLoading(CacheKey constKey) {
// Remove this Thread from the underConstruction map and wake up
// those who have been waiting for me to complete this bundle
// loading.
Thread me = Thread.currentThread();
assert (underConstruction.get(constKey) == me);
underConstruction.remove(constKey);
synchronized (me) {
me.notifyAll();
}
}
/**
* Throw a MissingResourceException with proper message
*/
private static final void throwMissingResourceException(String baseName,
Locale locale,
Throwable cause) {
// If the cause is a MissingResourceException, avoid creating
// a long chain. (6355009)
if (cause instanceof MissingResourceException) {
cause = null;
}
throw new MissingResourceException("Can't find bundle for base name "
+ baseName + ", locale " + locale,
baseName + "_" + locale, // className
"", // key
cause);
}
/**
* Finds a bundle in the cache. Any expired bundles are marked as
* `expired' and removed from the cache upon return.
*
* @param cacheKey the key to look up the cache
* @param control the Control to be used for the expiration control
* @return the cached bundle, or null if the bundle is not found in the
* cache or its parent has expired. <code>bundle.expire</code> is true
* upon return if the bundle in the cache has expired.
*/
private static final ResourceBundle findBundleInCache(CacheKey cacheKey,
Control control) {
BundleReference bundleRef = cacheList.get(cacheKey);
if (bundleRef == null) {
return null;
}
ResourceBundle bundle = bundleRef.get();
if (bundle == null) {
return null;
}
ResourceBundle p = bundle.parent;
assert p != NONEXISTENT_BUNDLE;
// If the parent has expired, then this one must also expire. We
// check only the immediate parent because the actual loading is
// done from the root (base) to leaf (child) and the purpose of
// checking is to propagate expiration towards the leaf. For
// example, if the requested locale is ja_JP_JP and there are
// bundles for all of the candidates in the cache, we have a list,
//
// base <- ja <- ja_JP <- ja_JP_JP
//
// If ja has expired, then it will reload ja and the list becomes a
// tree.
//
// base <- ja (new)
// " <- ja (expired) <- ja_JP <- ja_JP_JP
//
// When looking up ja_JP in the cache, it finds ja_JP in the cache
// which references to the expired ja. Then, ja_JP is marked as
// expired and removed from the cache. This will be propagated to
// ja_JP_JP.
//
// Now, it's possible, for example, that while loading new ja_JP,
// someone else has started loading the same bundle and finds the
// base bundle has expired. Then, what we get from the first
// getBundle call includes the expired base bundle. However, if
// someone else didn't start its loading, we wouldn't know if the
// base bundle has expired at the end of the loading process. The
// expiration control doesn't guarantee that the returned bundle and
// its parents haven't expired.
//
// We could check the entire parent chain to see if there's any in
// the chain that has expired. But this process may never end. An
// extreme case would be that getTimeToLive returns 0 and
// needsReload always returns true.
if (p != null && p.expired) {
assert bundle != NONEXISTENT_BUNDLE;
bundle.expired = true;
bundle.cacheKey = null;
cacheList.remove(cacheKey, bundleRef);
bundle = null;
} else {
CacheKey key = bundleRef.getCacheKey();
long expirationTime = key.expirationTime;
if (!bundle.expired && expirationTime >= 0 &&
expirationTime <= System.currentTimeMillis()) {
// its TTL period has expired.
if (bundle != NONEXISTENT_BUNDLE) {
// Synchronize here to call needsReload to avoid
// redundant concurrent calls for the same bundle.
synchronized (bundle) {
expirationTime = key.expirationTime;
if (!bundle.expired && expirationTime >= 0 &&
expirationTime <= System.currentTimeMillis()) {
try {
bundle.expired = control.needsReload(key.getName(),
key.getLocale(),
key.getFormat(),
key.getLoader(),
bundle,
key.loadTime);
} catch (Exception e) {
cacheKey.setCause(e);
}
if (bundle.expired) {
// If the bundle needs to be reloaded, then
// remove the bundle from the cache, but
// return the bundle with the expired flag
// on.
bundle.cacheKey = null;
cacheList.remove(cacheKey, bundleRef);
} else {
// Update the expiration control info. and reuse
// the same bundle instance
setExpirationTime(key, control);
}
}
}
} else {
// We just remove NONEXISTENT_BUNDLE from the cache.
cacheList.remove(cacheKey, bundleRef);
bundle = null;
}
}
}
return bundle;
}
/**
* Put a new bundle in the cache.
*
* @param cacheKey the key for the resource bundle
* @param bundle the resource bundle to be put in the cache
* @return the ResourceBundle for the cacheKey; if someone has put
* the bundle before this call, the one found in the cache is
* returned.
*/
private static final ResourceBundle putBundleInCache(CacheKey cacheKey,
ResourceBundle bundle,
Control control) {
setExpirationTime(cacheKey, control);
if (cacheKey.expirationTime != Control.TTL_DONT_CACHE) {
CacheKey key = (CacheKey) cacheKey.clone();
BundleReference bundleRef = new BundleReference(bundle, referenceQueue, key);
bundle.cacheKey = key;
// Put the bundle in the cache if it's not been in the cache.
BundleReference result = cacheList.putIfAbsent(key, bundleRef);
// If someone else has put the same bundle in the cache before
// us and it has not expired, we should use the one in the cache.
if (result != null) {
ResourceBundle rb = result.get();
if (rb != null && !rb.expired) {
// Clear the back link to the cache key
bundle.cacheKey = null;
bundle = rb;
// Clear the reference in the BundleReference so that
// it won't be enqueued.
bundleRef.clear();
} else {
// Replace the invalid (garbage collected or expired)
// instance with the valid one.
cacheList.put(key, bundleRef);
}
}
}
return bundle;
}
private static final void setExpirationTime(CacheKey cacheKey, Control control) {
long ttl = control.getTimeToLive(cacheKey.getName(),
cacheKey.getLocale());
if (ttl >= 0) {
// If any expiration time is specified, set the time to be
// expired in the cache.
long now = System.currentTimeMillis();
cacheKey.loadTime = now;
cacheKey.expirationTime = now + ttl;
} else if (ttl >= Control.TTL_NO_EXPIRATION_CONTROL) {
cacheKey.expirationTime = ttl;
} else {
throw new IllegalArgumentException("Invalid Control: TTL=" + ttl);
}
}
/**
* Removes all resource bundles from the cache that have been loaded
* using the caller's class loader.
*
* @since 1.6
* @see ResourceBundle.Control#getTimeToLive(String,Locale)
*/
public static final void clearCache() {
clearCache(getLoader());
}
/**
* Removes all resource bundles from the cache that have been loaded
* using the given class loader.
*
* @param loader the class loader
* @exception NullPointerException if <code>loader</code> is null
* @since 1.6
* @see ResourceBundle.Control#getTimeToLive(String,Locale)
*/
public static final void clearCache(ClassLoader loader) {
if (loader == null) {
throw new NullPointerException();
}
Set<CacheKey> set = cacheList.keySet();
for (CacheKey key : set) {
if (key.getLoader() == loader) {
set.remove(key);
}
}
}
/**
* 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.
*
* @return an <code>Enumeration</code> of the keys contained in
* this <code>ResourceBundle</code> and its parent bundles.
*/
public abstract Enumeration<String> getKeys();
/**
* Determines whether the given <code>key</code> is contained in
* this <code>ResourceBundle</code> or its parent bundles.
*
* @param key
* the resource <code>key</code>
* @return <code>true</code> if the given <code>key</code> is
* contained in this <code>ResourceBundle</code> or its
* parent bundles; <code>false</code> otherwise.
* @exception NullPointerException
* if <code>key</code> is <code>null</code>
* @since 1.6
*/
public boolean containsKey(String key) {
if (key == null) {
throw new NullPointerException();
}
for (ResourceBundle rb = this; rb != null; rb = rb.parent) {
if (rb.handleKeySet().contains(key)) {
return true;
}
}
return false;
}
/**
* Returns a <code>Set</code> of all keys contained in this
* <code>ResourceBundle</code> and its parent bundles.
*
* @return a <code>Set</code> of all keys contained in this
* <code>ResourceBundle</code> and its parent bundles.
* @since 1.6
*/
public Set<String> keySet() {
Set<String> keys = new HashSet<String>();
for (ResourceBundle rb = this; rb != null; rb = rb.parent) {
keys.addAll(rb.handleKeySet());
}
return keys;
}
/**
* Returns a <code>Set</code> of the keys contained <em>only</em>
* in this <code>ResourceBundle</code>.
*
* <p>The default implementation returns a <code>Set</code> of the
* keys returned by the {@link #getKeys() getKeys} method except
* for the ones for which the {@link #handleGetObject(String)
* handleGetObject} method returns <code>null</code>. Once the
* <code>Set</code> has been created, the value is kept in this
* <code>ResourceBundle</code> in order to avoid producing the
* same <code>Set</code> in the next calls. Override this method
* in subclass implementations for faster handling.
*
* @return a <code>Set</code> of the keys contained only in this
* <code>ResourceBundle</code>
* @since 1.6
*/
protected Set<String> handleKeySet() {
if (keySet == null) {
synchronized (this) {
if (keySet == null) {
Set<String> keys = new HashSet<String>();
Enumeration<String> enumKeys = getKeys();
while (enumKeys.hasMoreElements()) {
String key = enumKeys.nextElement();
if (handleGetObject(key) != null) {
keys.add(key);
}
}
keySet = keys;
}
}
}
return keySet;
}
/**
* <code>ResourceBundle.Control</code> defines a set of callback methods
* that are invoked by the {@link ResourceBundle#getBundle(String,
* Locale, ClassLoader, Control) ResourceBundle.getBundle} factory
* methods during the bundle loading process. In other words, a
* <code>ResourceBundle.Control</code> collaborates with the factory
* methods for loading resource bundles. The default implementation of
* the callback methods provides the information necessary for the
* factory methods to perform the <a
* href="./ResourceBundle.html#default_behavior">default behavior</a>.
*
* <p>In addition to the callback methods, the {@link
* #toBundleName(String, Locale) toBundleName} and {@link
* #toResourceName(String, String) toResourceName} methods are defined
* primarily for convenience in implementing the callback
* methods. However, the <code>toBundleName</code> method could be
* overridden to provide different conventions in the organization and
* packaging of localized resources. The <code>toResourceName</code>
* method is <code>final</code> to avoid use of wrong resource and class
* name separators.
*
* <p>Two factory methods, {@link #getControl(List)} and {@link
* #getNoFallbackControl(List)}, provide
* <code>ResourceBundle.Control</code> instances that implement common
* variations of the default bundle loading process.
*
* <p>The formats returned by the {@link Control#getFormats(String)
* getFormats} method and candidate locales returned by the {@link
* ResourceBundle.Control#getCandidateLocales(String, Locale)
* getCandidateLocales} method must be consistent in all
* <code>ResourceBundle.getBundle</code> invocations for the same base
* bundle. Otherwise, the <code>ResourceBundle.getBundle</code> methods
* may return unintended bundles. For example, if only
* <code>"java.class"</code> is returned by the <code>getFormats</code>
* method for the first call to <code>ResourceBundle.getBundle</code>
* and only <code>"java.properties"</code> for the second call, then the
* second call will return the class-based one that has been cached
* during the first call.
*
* <p>A <code>ResourceBundle.Control</code> instance must be thread-safe
* if it's simultaneously used by multiple threads.
* <code>ResourceBundle.getBundle</code> does not synchronize to call
* the <code>ResourceBundle.Control</code> methods. The default
* implementations of the methods are thread-safe.
*
* <p>Applications can specify <code>ResourceBundle.Control</code>
* instances returned by the <code>getControl</code> factory methods or
* created from a subclass of <code>ResourceBundle.Control</code> to
* customize the bundle loading process. The following are examples of
* changing the default bundle loading process.
*
* <p><b>Example 1</b>
*
* <p>The following code lets <code>ResourceBundle.getBundle</code> look
* up only properties-based resources.
*
* <pre>
* import java.util.*;
* import static java.util.ResourceBundle.Control.*;
* ...
* ResourceBundle bundle =
* ResourceBundle.getBundle("MyResources", new Locale("fr", "CH"),
* ResourceBundle.Control.getControl(FORMAT_PROPERTIES));
* </pre>
*
* Given the resource bundles in the <a
* href="./ResourceBundle.html#default_behavior_example">example</a> in
* the <code>ResourceBundle.getBundle</code> description, this
* <code>ResourceBundle.getBundle</code> call loads
* <code>MyResources_fr_CH.properties</code> whose parent is
* <code>MyResources_fr.properties</code> whose parent is
* <code>MyResources.properties</code>. (<code>MyResources_fr_CH.properties</code>
* is not hidden, but <code>MyResources_fr_CH.class</code> is.)
*
* <p><b>Example 2</b>
*
* <p>The following is an example of loading XML-based bundles
* using {@link Properties#loadFromXML(java.io.InputStream)
* Properties.loadFromXML}.
*
* <pre>
* ResourceBundle rb = ResourceBundle.getBundle("Messages",
* new ResourceBundle.Control() {
* public List<String> getFormats(String baseName) {
* if (baseName == null)
* throw new NullPointerException();
* return Arrays.asList("xml");
* }
* public ResourceBundle newBundle(String baseName,
* Locale locale,
* String format,
* ClassLoader loader,
* boolean reload)
* throws IllegalAccessException,
* InstantiationException,
* IOException {
* if (baseName == null || locale == null
* || format == null || loader == null)
* throw new NullPointerException();
* ResourceBundle bundle = null;
* if (format.equals("xml")) {
* String bundleName = toBundleName(baseName, locale);
* String resourceName = toResourceName(bundleName, format);
* InputStream stream = null;
* if (reload) {
* URL url = loader.getResource(resourceName);
* if (url != null) {
* URLConnection connection = url.openConnection();
* if (connection != null) {
* // Disable caches to get fresh data for
* // reloading.
* connection.setUseCaches(false);
* stream = connection.getInputStream();
* }
* }
* } else {
* stream = loader.getResourceAsStream(resourceName);
* }
* if (stream != null) {
* BufferedInputStream bis = new BufferedInputStream(stream);
* bundle = new XMLResourceBundle(bis);
* bis.close();
* }
* }
* return bundle;
* }
* });
*
* ...
*
* private static class XMLResourceBundle extends ResourceBundle {
* private Properties props;
* XMLResourceBundle(InputStream stream) throws IOException {
* props = new Properties();
* props.loadFromXML(stream);
* }
* protected Object handleGetObject(String key) {
* return props.getProperty(key);
* }
* public Enumeration<String> getKeys() {
* ...
* }
* }
* </pre>
*
* @since 1.6
*/
public static class Control {
/**
* The default format <code>List</code>, which contains the strings
* <code>"java.class"</code> and <code>"java.properties"</code>, in
* this order. This <code>List</code> is {@linkplain
* Collections#unmodifiableList(List) unmodifiable}.
*
* @see #getFormats(String)
*/
public static final List<String> FORMAT_DEFAULT
= Collections.unmodifiableList(Arrays.asList("java.class",
"java.properties"));
/**
* The class-only format <code>List</code> containing
* <code>"java.class"</code>. This <code>List</code> is {@linkplain
* Collections#unmodifiableList(List) unmodifiable}.
*
* @see #getFormats(String)
*/
public static final List<String> FORMAT_CLASS
= Collections.unmodifiableList(Arrays.asList("java.class"));
/**
* The properties-only format <code>List</code> containing
* <code>"java.properties"</code>. This <code>List</code> is
* {@linkplain Collections#unmodifiableList(List) unmodifiable}.
*
* @see #getFormats(String)
*/
public static final List<String> FORMAT_PROPERTIES
= Collections.unmodifiableList(Arrays.asList("java.properties"));
/**
* The time-to-live constant for not caching loaded resource bundle
* instances.
*
* @see #getTimeToLive(String, Locale)
*/
public static final long TTL_DONT_CACHE = -1;
/**
* The time-to-live constant for disabling the expiration control
* for loaded resource bundle instances in the cache.
*
* @see #getTimeToLive(String, Locale)
*/
public static final long TTL_NO_EXPIRATION_CONTROL = -2;
private static final Control INSTANCE = new Control();
/**
* Sole constructor. (For invocation by subclass constructors,
* typically implicit.)
*/
protected Control() {
}
/**
* Returns a <code>ResourceBundle.Control</code> in which the {@link
* #getFormats(String) getFormats} method returns the specified
* <code>formats</code>. The <code>formats</code> must be equal to
* one of {@link Control#FORMAT_PROPERTIES}, {@link
* Control#FORMAT_CLASS} or {@link
* Control#FORMAT_DEFAULT}. <code>ResourceBundle.Control</code>
* instances returned by this method are singletons and thread-safe.
*
* <p>Specifying {@link Control#FORMAT_DEFAULT} is equivalent to
* instantiating the <code>ResourceBundle.Control</code> class,
* except that this method returns a singleton.
*
* @param formats
* the formats to be returned by the
* <code>ResourceBundle.Control.getFormats</code> method
* @return a <code>ResourceBundle.Control</code> supporting the
* specified <code>formats</code>
* @exception NullPointerException
* if <code>formats</code> is <code>null</code>
* @exception IllegalArgumentException
* if <code>formats</code> is unknown
*/
public static final Control getControl(List<String> formats) {
if (formats.equals(Control.FORMAT_PROPERTIES)) {
return SingleFormatControl.PROPERTIES_ONLY;
}
if (formats.equals(Control.FORMAT_CLASS)) {
return SingleFormatControl.CLASS_ONLY;
}
if (formats.equals(Control.FORMAT_DEFAULT)) {
return Control.INSTANCE;
}
throw new IllegalArgumentException();
}
/**
* Returns a <code>ResourceBundle.Control</code> in which the {@link
* #getFormats(String) getFormats} method returns the specified
* <code>formats</code> and the {@link
* Control#getFallbackLocale(String, Locale) getFallbackLocale}
* method returns <code>null</code>. The <code>formats</code> must
* be equal to one of {@link Control#FORMAT_PROPERTIES}, {@link
* Control#FORMAT_CLASS} or {@link Control#FORMAT_DEFAULT}.
* <code>ResourceBundle.Control</code> instances returned by this
* method are singletons and thread-safe.
*
* @param formats
* the formats to be returned by the
* <code>ResourceBundle.Control.getFormats</code> method
* @return a <code>ResourceBundle.Control</code> supporting the
* specified <code>formats</code> with no fallback
* <code>Locale</code> support
* @exception NullPointerException
* if <code>formats</code> is <code>null</code>
* @exception IllegalArgumentException
* if <code>formats</code> is unknown
*/
public static final Control getNoFallbackControl(List<String> formats) {
if (formats.equals(Control.FORMAT_DEFAULT)) {
return NoFallbackControl.NO_FALLBACK;
}
if (formats.equals(Control.FORMAT_PROPERTIES)) {
return NoFallbackControl.PROPERTIES_ONLY_NO_FALLBACK;
}
if (formats.equals(Control.FORMAT_CLASS)) {
return NoFallbackControl.CLASS_ONLY_NO_FALLBACK;
}
throw new IllegalArgumentException();
}
/**
* Returns a <code>List</code> of <code>String</code>s containing
* formats to be used to load resource bundles for the given
* <code>baseName</code>. The <code>ResourceBundle.getBundle</code>
* factory method tries to load resource bundles with formats in the
* order specified by the list. The list returned by this method
* must have at least one <code>String</code>. The predefined
* formats are <code>"java.class"</code> for class-based resource
* bundles and <code>"java.properties"</code> for {@linkplain
* PropertyResourceBundle properties-based} ones. Strings starting
* with <code>"java."</code> are reserved for future extensions and
* must not be used by application-defined formats.
*
* <p>It is not a requirement to return an immutable (unmodifiable)
* <code>List</code>. However, the returned <code>List</code> must
* not be mutated after it has been returned by
* <code>getFormats</code>.
*
* <p>The default implementation returns {@link #FORMAT_DEFAULT} so
* that the <code>ResourceBundle.getBundle</code> factory method
* looks up first class-based resource bundles, then
* properties-based ones.
*
* @param baseName
* the base name of the resource bundle, a fully qualified class
* name
* @return a <code>List</code> of <code>String</code>s containing
* formats for loading resource bundles.
* @exception NullPointerException
* if <code>baseName</code> is null
* @see #FORMAT_DEFAULT
* @see #FORMAT_CLASS
* @see #FORMAT_PROPERTIES
*/
public List<String> getFormats(String baseName) {
if (baseName == null) {
throw new NullPointerException();
}
return FORMAT_DEFAULT;
}
/**
* Returns a <code>List</code> of <code>Locale</code>s as candidate
* locales for <code>baseName</code> and <code>locale</code>. This
* method is called by the <code>ResourceBundle.getBundle</code>
* factory method each time the factory method tries finding a
* resource bundle for a target <code>Locale</code>.
*
* <p>The sequence of the candidate locales also corresponds to the
* runtime resource lookup path (also known as the <I>parent
* chain</I>), if the corresponding resource bundles for the
* candidate locales exist and their parents are not defined by
* loaded resource bundles themselves. The last element of the list
* must be a {@linkplain Locale#ROOT root locale} if it is desired to
* have the base bundle as the terminal of the parent chain.
*
* <p>If the given locale is equal to <code>Locale.ROOT</code> (the
* root locale), a <code>List</code> containing only the root
* <code>Locale</code> must be returned. In this case, the
* <code>ResourceBundle.getBundle</code> factory method loads only
* the base bundle as the resulting resource bundle.
*
* <p>It is not a requirement to return an immutable
* (unmodifiable) <code>List</code>. However, the returned
* <code>List</code> must not be mutated after it has been
* returned by <code>getCandidateLocales</code>.
*
* <p>The default implementation returns a <code>List</code> containing
* <code>Locale</code>s in the following sequence:
* <pre>
* Locale(language, country, variant)
* Locale(language, country)
* Locale(language)
* Locale.ROOT
* </pre>
* where <code>language</code>, <code>country</code> and
* <code>variant</code> are the language, country and variant values
* of the given <code>locale</code>, respectively. Locales where the
* final component values are empty strings are omitted.
*
* <p>The default implementation uses an {@link ArrayList} that
* overriding implementations may modify before returning it to the
* caller. However, a subclass must not modify it after it has
* been returned by <code>getCandidateLocales</code>.
*
* <p>For example, if the given <code>baseName</code> is "Messages"
* and the given <code>locale</code> is
* <code>Locale("ja", "", "XX")</code>, then a
* <code>List</code> of <code>Locale</code>s:
* <pre>
* Locale("ja", "", "XX")
* Locale("ja")
* Locale.ROOT
* </pre>
* is returned. And if the resource bundles for the "ja" and
* "" <code>Locale</code>s are found, then the runtime resource
* lookup path (parent chain) is:
* <pre>
* Messages_ja -> Messages
* </pre>
*
* @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
* @return a <code>List</code> of candidate
* <code>Locale</code>s for the given <code>locale</code>
* @exception NullPointerException
* if <code>baseName</code> or <code>locale</code> is
* <code>null</code>
*/
public List<Locale> getCandidateLocales(String baseName, Locale locale) {
if (baseName == null) {
throw new NullPointerException();
}
String language = locale.getLanguage();
String country = locale.getCountry();
String variant = locale.getVariant();
List<Locale> locales = new ArrayList<Locale>(4);
if (variant.length() > 0) {
locales.add(locale);
}
if (country.length() > 0) {
locales.add((locales.size() == 0) ?
locale : Locale.getInstance(language, country, ""));
}
if (language.length() > 0) {
locales.add((locales.size() == 0) ?
locale : Locale.getInstance(language, "", ""));
}
locales.add(Locale.ROOT);
return locales;
}
/**
* Returns a <code>Locale</code> to be used as a fallback locale for
* further resource bundle searches by the
* <code>ResourceBundle.getBundle</code> factory method. This method
* is called from the factory method every time when no resulting
* resource bundle has been found for <code>baseName</code> and
* <code>locale</code>, where locale is either the parameter for
* <code>ResourceBundle.getBundle</code> or the previous fallback
* locale returned by this method.
*
* <p>The method returns <code>null</code> if no further fallback
* search is desired.
*
* <p>The default implementation returns the {@linkplain
* Locale#getDefault() default <code>Locale</code>} if the given
* <code>locale</code> isn't the default one. Otherwise,
* <code>null</code> is returned.
*
* @param baseName
* the base name of the resource bundle, a fully
* qualified class name for which
* <code>ResourceBundle.getBundle</code> has been
* unable to find any resource bundles (except for the
* base bundle)
* @param locale
* the <code>Locale</code> for which
* <code>ResourceBundle.getBundle</code> has been
* unable to find any resource bundles (except for the
* base bundle)
* @return a <code>Locale</code> for the fallback search,
* or <code>null</code> if no further fallback search
* is desired.
* @exception NullPointerException
* if <code>baseName</code> or <code>locale</code>
* is <code>null</code>
*/
public Locale getFallbackLocale(String baseName, Locale locale) {
if (baseName == null) {
throw new NullPointerException();
}
Locale defaultLocale = Locale.getDefault();
return locale.equals(defaultLocale) ? null : defaultLocale;
}
/**
* Instantiates a resource bundle for the given bundle name of the
* given format and locale, using the given class loader if
* necessary. This method returns <code>null</code> if there is no
* resource bundle available for the given parameters. If a resource
* bundle can't be instantiated due to an unexpected error, the
* error must be reported by throwing an <code>Error</code> or
* <code>Exception</code> rather than simply returning
* <code>null</code>.
*
* <p>If the <code>reload</code> flag is <code>true</code>, it
* indicates that this method is being called because the previously
* loaded resource bundle has expired.
*
* <p>The default implementation instantiates a
* <code>ResourceBundle</code> as follows.
*
* <ul>
*
* <li>The bundle name is obtained by calling {@link
* #toBundleName(String, Locale) toBundleName(baseName,
* locale)}.</li>
*
* <li>If <code>format</code> is <code>"java.class"</code>, the
* {@link Class} specified by the bundle name is loaded by calling
* {@link ClassLoader#loadClass(String)}. Then, a
* <code>ResourceBundle</code> is instantiated by calling {@link
* Class#newInstance()}. Note that the <code>reload</code> flag is
* ignored for loading class-based resource bundles in this default
* implementation.</li>
*
* <li>If <code>format</code> is <code>"java.properties"</code>,
* {@link #toResourceName(String, String) toResourceName(bundlename,
* "properties")} is called to get the resource name.
* If <code>reload</code> is <code>true</code>, {@link
* ClassLoader#getResource(String) load.getResource} is called
* to get a {@link URL} for creating a {@link
* URLConnection}. This <code>URLConnection</code> is used to
* {@linkplain URLConnection#setUseCaches(boolean) disable the
* caches} of the underlying resource loading layers,
* and to {@linkplain URLConnection#getInputStream() get an
* <code>InputStream</code>}.
* Otherwise, {@link ClassLoader#getResourceAsStream(String)
* loader.getResourceAsStream} is called to get an {@link
* InputStream}. Then, a {@link
* PropertyResourceBundle} is constructed with the
* <code>InputStream</code>.</li>
*
* <li>If <code>format</code> is neither <code>"java.class"</code>
* nor <code>"java.properties"</code>, an
* <code>IllegalArgumentException</code> is thrown.</li>
*
* </ul>
*
* @param baseName
* the base bundle name of the resource bundle, a fully
* qualified class name
* @param locale
* the locale for which the resource bundle should be
* instantiated
* @param format
* the resource bundle format to be loaded
* @param loader
* the <code>ClassLoader</code> to use to load the bundle
* @param reload
* the flag to indicate bundle reloading; <code>true</code>
* if reloading an expired resource bundle,
* <code>false</code> otherwise
* @return the resource bundle instance,
* or <code>null</code> if none could be found.
* @exception NullPointerException
* if <code>bundleName</code>, <code>locale</code>,
* <code>format</code>, or <code>loader</code> is
* <code>null</code>, or if <code>null</code> is returned by
* {@link #toBundleName(String, Locale) toBundleName}
* @exception IllegalArgumentException
* if <code>format</code> is unknown, or if the resource
* found for the given parameters contains malformed data.
* @exception ClassCastException
* if the loaded class cannot be cast to <code>ResourceBundle</code>
* @exception IllegalAccessException
* if the class or its nullary constructor is not
* accessible.
* @exception InstantiationException
* if the instantiation of a class fails for some other
* reason.
* @exception ExceptionInInitializerError
* if the initialization provoked by this method fails.
* @exception SecurityException
* If a security manager is present and creation of new
* instances is denied. See {@link Class#newInstance()}
* for details.
* @exception IOException
* if an error occurred when reading resources using
* any I/O operations
*/
public ResourceBundle newBundle(String baseName, Locale locale, String format,
ClassLoader loader, boolean reload)
throws IllegalAccessException, InstantiationException, IOException {
String bundleName = toBundleName(baseName, locale);
ResourceBundle bundle = null;
if (format.equals("java.class")) {
try {
Class<? extends ResourceBundle> bundleClass
= (Class<? extends ResourceBundle>)loader.loadClass(bundleName);
// If the class isn't a ResourceBundle subclass, throw a
// ClassCastException.
if (ResourceBundle.class.isAssignableFrom(bundleClass)) {
bundle = bundleClass.newInstance();
} else {
throw new ClassCastException(bundleClass.getName()
+ " cannot be cast to ResourceBundle");
}
} catch (ClassNotFoundException e) {
}
} else if (format.equals("java.properties")) {
final String resourceName = toResourceName(bundleName, "properties");
final ClassLoader classLoader = loader;
final boolean reloadFlag = reload;
InputStream stream = null;
try {
stream = AccessController.doPrivileged(
new PrivilegedExceptionAction<InputStream>() {
public InputStream run() throws IOException {
InputStream is = null;
if (reloadFlag) {
URL url = classLoader.getResource(resourceName);
if (url != null) {
URLConnection connection = url.openConnection();
if (connection != null) {
// Disable caches to get fresh data for
// reloading.
connection.setUseCaches(false);
is = connection.getInputStream();
}
}
} else {
is = classLoader.getResourceAsStream(resourceName);
}
return is;
}
});
} catch (PrivilegedActionException e) {
throw (IOException) e.getException();
}
if (stream != null) {
try {
bundle = new PropertyResourceBundle(stream);
} finally {
stream.close();
}
}
} else {
throw new IllegalArgumentException("unknown format: " + format);
}
return bundle;
}
/**
* Returns the time-to-live (TTL) value for resource bundles that
* are loaded under this
* <code>ResourceBundle.Control</code>. Positive time-to-live values
* specify the number of milliseconds a bundle can remain in the
* cache without being validated against the source data from which
* it was constructed. The value 0 indicates that a bundle must be
* validated each time it is retrieved from the cache. {@link
* #TTL_DONT_CACHE} specifies that loaded resource bundles are not
* put in the cache. {@link #TTL_NO_EXPIRATION_CONTROL} specifies
* that loaded resource bundles are put in the cache with no
* expiration control.
*
* <p>The expiration affects only the bundle loading process by the
* <code>ResourceBundle.getBundle</code> factory method. That is,
* if the factory method finds a resource bundle in the cache that
* has expired, the factory method calls the {@link
* #needsReload(String, Locale, String, ClassLoader, ResourceBundle,
* long) needsReload} method to determine whether the resource
* bundle needs to be reloaded. If <code>needsReload</code> returns
* <code>true</code>, the cached resource bundle instance is removed
* from the cache. Otherwise, the instance stays in the cache,
* updated with the new TTL value returned by this method.
*
* <p>All cached resource bundles are subject to removal from the
* cache due to memory constraints of the runtime environment.
* Returning a large positive value doesn't mean to lock loaded
* resource bundles in the cache.
*
* <p>The default implementation returns {@link #TTL_NO_EXPIRATION_CONTROL}.
*
* @param baseName
* the base name of the resource bundle for which the
* expiration value is specified.
* @param locale
* the locale of the resource bundle for which the
* expiration value is specified.
* @return the time (0 or a positive millisecond offset from the
* cached time) to get loaded bundles expired in the cache,
* {@link #TTL_NO_EXPIRATION_CONTROL} to disable the
* expiration control, or {@link #TTL_DONT_CACHE} to disable
* caching.
* @exception NullPointerException
* if <code>baseName</code> or <code>locale</code> is
* <code>null</code>
*/
public long getTimeToLive(String baseName, Locale locale) {
if (baseName == null || locale == null) {
throw new NullPointerException();
}
return TTL_NO_EXPIRATION_CONTROL;
}
/**
* Determines if the expired <code>bundle</code> in the cache needs
* to be reloaded based on the loading time given by
* <code>loadTime</code> or some other criteria. The method returns
* <code>true</code> if reloading is required; <code>false</code>
* otherwise. <code>loadTime</code> is a millisecond offset since
* the <a href="Calendar.html#Epoch"> <code>Calendar</code>
* Epoch</a>.
*
* The calling <code>ResourceBundle.getBundle</code> factory method
* calls this method on the <code>ResourceBundle.Control</code>
* instance used for its current invocation, not on the instance
* used in the invocation that originally loaded the resource
* bundle.
*
* <p>The default implementation compares <code>loadTime</code> and
* the last modified time of the source data of the resource
* bundle. If it's determined that the source data has been modified
* since <code>loadTime</code>, <code>true</code> is
* returned. Otherwise, <code>false</code> is returned. This
* implementation assumes that the given <code>format</code> is the
* same string as its file suffix if it's not one of the default
* formats, <code>"java.class"</code> or
* <code>"java.properties"</code>.
*
* @param baseName
* the base bundle name of the resource bundle, a
* fully qualified class name
* @param locale
* the locale for which the resource bundle
* should be instantiated
* @param format
* the resource bundle format to be loaded
* @param loader
* the <code>ClassLoader</code> to use to load the bundle
* @param bundle
* the resource bundle instance that has been expired
* in the cache
* @param loadTime
* the time when <code>bundle</code> was loaded and put
* in the cache
* @return <code>true</code> if the expired bundle needs to be
* reloaded; <code>false</code> otherwise.
* @exception NullPointerException
* if <code>baseName</code>, <code>locale</code>,
* <code>format</code>, <code>loader</code>, or
* <code>bundle</code> is <code>null</code>
*/
public boolean needsReload(String baseName, Locale locale,
String format, ClassLoader loader,
ResourceBundle bundle, long loadTime) {
if (bundle == null) {
throw new NullPointerException();
}
if (format.equals("java.class") || format.equals("java.properties")) {
format = format.substring(5);
}
boolean result = false;
try {
String resourceName = toResourceName(toBundleName(baseName, locale), format);
URL url = loader.getResource(resourceName);
if (url != null) {
long lastModified = 0;
URLConnection connection = url.openConnection();
if (connection != null) {
// disable caches to get the correct data
connection.setUseCaches(false);
if (connection instanceof JarURLConnection) {
JarEntry ent = ((JarURLConnection)connection).getJarEntry();
if (ent != null) {
lastModified = ent.getTime();
if (lastModified == -1) {
lastModified = 0;
}
}
} else {
lastModified = connection.getLastModified();
}
}
result = lastModified >= loadTime;
}
} catch (NullPointerException npe) {
throw npe;
} catch (Exception e) {
// ignore other exceptions
}
return result;
}
/**
* Converts the given <code>baseName</code> and <code>locale</code>
* to the bundle name. This method is called from the default
* implementation of the {@link #newBundle(String, Locale, String,
* ClassLoader, boolean) newBundle} and {@link #needsReload(String,
* Locale, String, ClassLoader, ResourceBundle, long) needsReload}
* methods.
*
* <p>This implementation returns the following value:
* <pre>
* baseName + "_" + language + "_" + country + "_" + variant
* </pre>
* where <code>language</code>, <code>country</code> and
* <code>variant</code> are the language, country and variant values
* of <code>locale</code>, respectively. Final component values that
* are empty Strings are omitted along with the preceding '_'. If
* all of the values are empty strings, then <code>baseName</code>
* is returned.
*
* <p>For example, if <code>baseName</code> is
* <code>"baseName"</code> and <code>locale</code> is
* <code>Locale("ja", "", "XX")</code>, then
* <code>"baseName_ja_ _XX"</code> is returned. If the given
* locale is <code>Locale("en")</code>, then
* <code>"baseName_en"</code> is returned.
*
* <p>Overriding this method allows applications to use different
* conventions in the organization and packaging of localized
* resources.
*
* @param baseName
* the base name of the resource bundle, a fully
* qualified class name
* @param locale
* the locale for which a resource bundle should be
* loaded
* @return the bundle name for the resource bundle
* @exception NullPointerException
* if <code>baseName</code> or <code>locale</code>
* is <code>null</code>
*/
public String toBundleName(String baseName, Locale locale) {
if (locale == Locale.ROOT) {
return baseName;
}
String language = locale.getLanguage();
String country = locale.getCountry();
String variant = locale.getVariant();
if (language == "" && country == "" && variant == "") {
return baseName;
}
StringBuilder sb = new StringBuilder(baseName);
sb.append('_');
if (variant != "") {
sb.append(language).append('_').append(country).append('_').append(variant);
} else if (country != "") {
sb.append(language).append('_').append(country);
} else {
sb.append(language);
}
return sb.toString();
}
/**
* Converts the given <code>bundleName</code> to the form required
* by the {@link ClassLoader#getResource ClassLoader.getResource}
* method by replacing all occurrences of <code>'.'</code> in
* <code>bundleName</code> with <code>'/'</code> and appending a
* <code>'.'</code> and the given file <code>suffix</code>. For
* example, if <code>bundleName</code> is
* <code>"foo.bar.MyResources_ja_JP"</code> and <code>suffix</code>
* is <code>"properties"</code>, then
* <code>"foo/bar/MyResources_ja_JP.properties"</code> is returned.
*
* @param bundleName
* the bundle name
* @param suffix
* the file type suffix
* @return the converted resource name
* @exception NullPointerException
* if <code>bundleName</code> or <code>suffix</code>
* is <code>null</code>
*/
public final String toResourceName(String bundleName, String suffix) {
StringBuilder sb = new StringBuilder(bundleName.length() + 1 + suffix.length());
sb.append(bundleName.replace('.', '/')).append('.').append(suffix);
return sb.toString();
}
}
private static class SingleFormatControl extends Control {
private static final Control PROPERTIES_ONLY
= new SingleFormatControl(FORMAT_PROPERTIES);
private static final Control CLASS_ONLY
= new SingleFormatControl(FORMAT_CLASS);
private final List<String> formats;
protected SingleFormatControl(List<String> formats) {
this.formats = formats;
}
public List<String> getFormats(String baseName) {
if (baseName == null) {
throw new NullPointerException();
}
return formats;
}
}
private static final class NoFallbackControl extends SingleFormatControl {
private static final Control NO_FALLBACK
= new NoFallbackControl(FORMAT_DEFAULT);
private static final Control PROPERTIES_ONLY_NO_FALLBACK
= new NoFallbackControl(FORMAT_PROPERTIES);
private static final Control CLASS_ONLY_NO_FALLBACK
= new NoFallbackControl(FORMAT_CLASS);
protected NoFallbackControl(List<String> formats) {
super(formats);
}
public Locale getFallbackLocale(String baseName, Locale locale) {
if (baseName == null || locale == null) {
throw new NullPointerException();
}
return null;
}
}
}