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ResourceBundle.javaAPI DocJava SE 5 API48263Fri Aug 26 14:57:24 BST 2005java.util

ResourceBundle

public abstract class ResourceBundle extends Object
Resource bundles contain locale-specific objects. When your program needs a locale-specific resource, a String 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.

This allows you to write programs that can:

  • be easily localized, or translated, into different languages
  • handle multiple locales at once
  • be easily modified later to support even more locales

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".

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 String that's used on a button for canceling operations. In "MyResources" the String may contain "Cancel" and in "MyResources_de" it may contain "Abbrechen".

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.

When your program needs a locale-specific object, it loads the ResourceBundle class using the {@link #getBundle(java.lang.String, java.util.Locale) getBundle} method: 

ResourceBundle myResources =
ResourceBundle.getBundle("MyResources", currentLocale);

Resource bundles contain key/value pairs. The keys uniquely identify a locale-specific object in the bundle. Here's an example of a ListResourceBundle that contains two key/value pairs: 

public class MyResources extends ListResourceBundle {
public Object[][] getContents() {
return contents;
}
static final Object[][] contents = {
// LOCALIZE THIS
{"OkKey", "OK"},
{"CancelKey", "Cancel"},
// END OF MATERIAL TO LOCALIZE
};
}
Keys are always Strings. In this example, the keys are "OkKey" and "CancelKey". In the above example, the values are also Strings--"OK" and "Cancel"--but they don't have to be. The values can be any type of object.

You retrieve an object from resource bundle using the appropriate getter method. Because "OkKey" and "CancelKey" are both strings, you would use getString to retrieve them: 

button1 = new Button(myResources.getString("OkKey"));
button2 = new Button(myResources.getString("CancelKey"));
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 MissingResourceException.

Besides getString, ResourceBundle also provides a method for getting string arrays, getStringArray, as well as a generic getObject method for any other type of object. When using getObject, you'll have to cast the result to the appropriate type. For example: 

int[] myIntegers = (int[]) myResources.getObject("intList");

The Java 2 platform provides two subclasses of ResourceBundle, ListResourceBundle and PropertyResourceBundle, that provide a fairly simple way to create resources. As you saw briefly in a previous example, ListResourceBundle manages its resource as a List of key/value pairs. PropertyResourceBundle uses a properties file to manage its resources.

If ListResourceBundle or PropertyResourceBundle do not suit your needs, you can write your own ResourceBundle subclass. Your subclasses must override two methods: handleGetObject and getKeys().

The following is a very simple example of a ResourceBundle subclass, MyResources, that manages two resources (for a larger number of resources you would probably use a Hashtable). Notice that you don't need to supply a value if a "parent-level" ResourceBundle handles the same key with the same value (as for the okKey below).

Example: 

// default (English language, United States)
public class MyResources extends ResourceBundle {
public Object handleGetObject(String key) {
if (key.equals("okKey")) return "Ok";
if (key.equals("cancelKey")) return "Cancel";
return null;
}
}

// German language
public class MyResources_de extends MyResources {
public Object handleGetObject(String key) {
// don't need okKey, since parent level handles it.
if (key.equals("cancelKey")) return "Abbrechen";
return null;
}
}
You do not have to restrict yourself to using a single family of ResourceBundles. For example, you could have a set of bundles for exception messages, ExceptionResources (ExceptionResources_fr, ExceptionResources_de, ...), and one for widgets, WidgetResource (WidgetResources_fr, WidgetResources_de, ...); breaking up the resources however you like.
see
ListResourceBundle
see
PropertyResourceBundle
see
MissingResourceException
since
JDK1.1

Fields Summary
private static final ResourceCacheKey
cacheKey
Static key used for resource lookups. Concurrent access to this object is controlled by synchronizing cacheList, not cacheKey. A static object is used to do cache lookups for performance reasons - the assumption being that synchronization has a lower overhead than object allocation and subsequent garbage collection.
private static final int
INITIAL_CACHE_SIZE
initial size of the bundle cache
private static final float
CACHE_LOAD_FACTOR
capacity of cache consumed before it should grow
private static final int
MAX_BUNDLES_SEARCHED
Maximum length of one branch of the resource search path tree. Used in getBundle.
private static final Hashtable
underConstruction
This Hashtable is used to keep multiple threads from loading the same bundle concurrently. The table entries are (cacheKey, thread) where cacheKey is the key for the bundle that is under construction and thread is the thread that is constructing the bundle. This list is manipulated in findBundle and putBundleInCache. Synchronization of this object is done through cacheList, not on this object.
private static final Object
NOT_FOUND
constant indicating that no resource bundle was found
private static sun.misc.SoftCache
cacheList
The cache is a map from cache keys (with bundle base name, locale, and class loader) to either a resource bundle (if one has been found) or NOT_FOUND (if no bundle has been found). The cache is a SoftCache, allowing bundles to be removed from the cache if they are no longer needed. This will also allow the cache keys to be reclaimed along with the ClassLoaders they reference. This variable would be better named "cache", but we keep the old name for compatibility with some workarounds for bug 4212439.
private static ReferenceQueue
referenceQueue
Queue for reference objects referring to class loaders.
protected ResourceBundle
parent
The parent bundle of this bundle. The parent bundle is searched by {@link #getObject getObject} when this bundle does not contain a particular resource.
private Locale
locale
The locale for this bundle.
Constructors Summary
public ResourceBundle()
Sole constructor. (For invocation by subclass constructors, typically implicit.)
Methods Summary
private static java.util.VectorcalculateBundleNames(java.lang.String baseName, java.util.Locale locale)
Calculate the bundles along the search path from the base bundle to the bundle specified by baseName and locale.

param
baseName the base bundle name
param
locale the locale
param
names the vector used to return the names of the bundles along the search path.

        final Vector result = new Vector(MAX_BUNDLES_SEARCHED);
        final String language = locale.getLanguage();
        final int languageLength = language.length();
        final String country = locale.getCountry();
        final int countryLength = country.length();
        final String variant = locale.getVariant();
        final int variantLength = variant.length();

        if (languageLength + countryLength + variantLength == 0) {
            //The locale is "", "", "".
            return result;
        }
        final StringBuffer temp = new StringBuffer(baseName);
        temp.append('_");
        temp.append(language);
        if (languageLength > 0) {
            result.addElement(temp.toString());
        }

        if (countryLength + variantLength == 0) {
            return result;
        }
        temp.append('_");
        temp.append(country);
        if (countryLength > 0) {
            result.addElement(temp.toString());
        }

        if (variantLength == 0) {
            return result;
        }
        temp.append('_");
        temp.append(variant);
        result.addElement(temp.toString());

        return result;
private static voidcleanUpConstructionList()
Remove any entries this thread may have in the construction list. This is done as cleanup in the case where a bundle can't be constructed.

        synchronized (cacheList) {
            final Collection entries = underConstruction.values();
            final Thread thisThread = Thread.currentThread();
            while (entries.remove(thisThread)) {
            }
        }
private static java.lang.ObjectfindBundle(java.lang.ClassLoader loader, java.lang.String bundleName, java.util.Locale defaultLocale, java.lang.String baseName, java.lang.Object parent)
Find a bundle in the cache or load it via the loader or a property file. If the bundle isn't found, an entry is put in the constructionCache and null is returned. If null is returned, the caller must define the bundle by calling putBundleInCache. This routine also propagates NOT_FOUND values from parent to child bundles when the parent is NOT_FOUND.

param
loader the loader to use when loading a bundle
param
bundleName the complete bundle name including locale extension
param
defaultLocale the default locale at the time getBundle was called
param
parent the parent of the resource bundle being loaded. null if the bundle is a root bundle
return
the bundle or null if the bundle could not be found in the cache or loaded.

        Object result;
        synchronized (cacheList) {
            // Before we do the real work of this method, see
            // whether we need to do some housekeeping:
            // If references to class loaders have been nulled out,
            // remove all related information from the cache
            Reference ref = referenceQueue.poll();
            while (ref != null) {
                cacheList.remove(((LoaderReference) ref).getCacheKey());
                ref = referenceQueue.poll();
            }
            
            //check for bundle in cache
            cacheKey.setKeyValues(loader, bundleName, defaultLocale);
            result = cacheList.get(cacheKey);
            if (result != null) {
                cacheKey.clear();
                return result;
            }
            // check to see if some other thread is building this bundle.
            // Note that there is a rare chance that this thread is already
            // working on this bundle, and in the process getBundle was called
            // again, in which case we can't wait (4300693)
            Thread builder = (Thread) underConstruction.get(cacheKey);
            boolean beingBuilt = (builder != null && builder != Thread.currentThread());
            //if some other thread is building the bundle...
            if (beingBuilt) {
                //while some other thread is building the bundle...
                while (beingBuilt) {
                    cacheKey.clear();
                    try {
                        //Wait until the bundle is complete
                        cacheList.wait();
                    } catch (InterruptedException e) {
                    }
                    cacheKey.setKeyValues(loader, bundleName, defaultLocale);
                    beingBuilt = underConstruction.containsKey(cacheKey);
                }
                //if someone constructed the bundle for us, return it
                result = cacheList.get(cacheKey);
                if (result != null) {
                    cacheKey.clear();
                    return result;
                }
            }
            //The bundle isn't in the cache, so we are now responsible for
            //loading it and adding it to the cache.
            final Object key = cacheKey.clone();
            underConstruction.put(key, Thread.currentThread());
            //the bundle is removed from the cache by putBundleInCache
            cacheKey.clear();
        }

        //try loading the bundle via the class loader
        result = loadBundle(loader, bundleName, defaultLocale);
        if (result != null) {
            // check whether we're still responsible for construction -
            // a recursive call to getBundle might have handled it (4300693)
            boolean constructing;
            synchronized (cacheList) {
                cacheKey.setKeyValues(loader, bundleName, defaultLocale);
                constructing = underConstruction.get(cacheKey) == Thread.currentThread();
                cacheKey.clear();
            }
            if (constructing) {
                // set the bundle's parent and put it in the cache
                final ResourceBundle bundle = (ResourceBundle)result;
                if (parent != NOT_FOUND && bundle.parent == null) {
                    bundle.setParent((ResourceBundle) parent);
                }
                bundle.setLocale(baseName, bundleName);
                putBundleInCache(loader, bundleName, defaultLocale, result);
            }
        }
        return result;
private static java.lang.ObjectfindBundleInCache(java.lang.ClassLoader loader, java.lang.String bundleName, java.util.Locale defaultLocale)
Find a bundle in the cache.

param
loader the class loader that is responsible for loading the bundle.
param
bundleName the complete name of the bundle including locale extension. ex. sun.text.resources.LocaleElements_fr_BE
param
defaultLocale the default locale at the time getBundle was called
return
the cached bundle. null if the bundle is not in the cache.

        //Synchronize access to cacheList, cacheKey, and underConstruction
        synchronized (cacheList) {
            cacheKey.setKeyValues(loader, bundleName, defaultLocale);
            Object result = cacheList.get(cacheKey);
            cacheKey.clear();
            return result;
        }
public static final java.util.ResourceBundlegetBundle(java.lang.String baseName)
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
getBundle(baseName, Locale.getDefault(), this.getClass().getClassLoader()),
except that getClassLoader() is run with the security privileges of ResourceBundle. See {@link #getBundle(java.lang.String, java.util.Locale, java.lang.ClassLoader) getBundle} for a complete description of the search and instantiation strategy.

param
baseName the base name of the resource bundle, a fully qualified class name
exception
java.lang.NullPointerException if baseName is null
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

        return getBundleImpl(baseName, Locale.getDefault(),
        /* must determine loader here, else we break stack invariant */
        getLoader());
public static final java.util.ResourceBundlegetBundle(java.lang.String baseName, java.util.Locale locale)
Gets a resource bundle using the specified base name and locale, and the caller's class loader. Calling this method is equivalent to calling
getBundle(baseName, locale, this.getClass().getClassLoader()),
except that getClassLoader() is run with the security privileges of ResourceBundle. See {@link #getBundle(java.lang.String, java.util.Locale, java.lang.ClassLoader) getBundle} for a complete description of the search and instantiation strategy.

param
baseName the base name of the resource bundle, a fully qualified class name
param
locale the locale for which a resource bundle is desired
exception
java.lang.NullPointerException if baseName or locale is null
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

        return getBundleImpl(baseName, locale, getLoader());
public static java.util.ResourceBundlegetBundle(java.lang.String baseName, java.util.Locale locale, java.lang.ClassLoader loader)
Gets a resource bundle using the specified base name, locale, and class loader.

Conceptually, getBundle uses the following strategy for locating and instantiating resource bundles:

getBundle 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 candidate bundle names. 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):

  • baseName + "_" + language1 + "_" + country1 + "_" + variant1
  • baseName + "_" + language1 + "_" + country1
  • baseName + "_" + language1
  • baseName + "_" + language2 + "_" + country2 + "_" + variant2
  • baseName + "_" + language2 + "_" + country2
  • baseName + "_" + language2
  • baseName

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.

getBundle then iterates over the candidate bundle names to find the first one for which it can instantiate an actual resource bundle. For each candidate bundle name, it attempts to create a resource bundle:

  • 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, getBundle creates a new instance of this class and uses it as the result resource bundle.
  • Otherwise, getBundle 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 getResource 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 result resource bundle.

If no result resource bundle has been found, a MissingResourceException is thrown.

Once a result resource bundle has been found, its parent chain is instantiated. getBundle 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.

Implementations of getBundle may cache instantiated resource bundles and return the same resource bundle instance multiple times. They may also vary the sequence in which resource bundles are instantiated as long as the selection of the result resource bundle and its parent chain are compatible with the description above.

The baseName argument should be a fully qualified class name. However, for compatibility with earlier versions, Sun's Java 2 runtime environments do not verify this, and so it is possible to access PropertyResourceBundles by specifying a path name (using "/") instead of a fully qualified class name (using ".").

Example: The following class and property files are provided: MyResources.class, MyResources_fr_CH.properties, MyResources_fr_CH.class, MyResources_fr.properties, MyResources_en.properties, MyResources_es_ES.class. The contents of all files are valid (that is, public non-abstract subclasses of ResourceBundle for the ".class" files, syntactically correct ".properties" files). The default locale is Locale("en", "GB").

Calling getBundle with the shown locale argument values instantiates resource bundles from the following sources:

  • Locale("fr", "CH"): result MyResources_fr_CH.class, parent MyResources_fr.properties, parent MyResources.class
  • Locale("fr", "FR"): result MyResources_fr.properties, parent MyResources.class
  • Locale("de", "DE"): result MyResources_en.properties, parent MyResources.class
  • Locale("en", "US"): result MyResources_en.properties, parent MyResources.class
  • Locale("es", "ES"): result MyResources_es_ES.class, parent MyResources.class
The file MyResources_fr_CH.properties is never used because it is hidden by MyResources_fr_CH.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
exception
java.lang.NullPointerException if baseName, locale, or loader is null
exception
MissingResourceException if no resource bundle for the specified base name can be found
return
a resource bundle for the given base name and locale
since
1.2

        if (loader == null) {
            throw new NullPointerException();
        }
        return getBundleImpl(baseName, locale, loader);
private static java.util.ResourceBundlegetBundleImpl(java.lang.String baseName, java.util.Locale locale, java.lang.ClassLoader loader)

        if (baseName == null) {
            throw new NullPointerException();
        }

        //fast path the case where the bundle is cached
        String bundleName = baseName;
        String localeSuffix = locale.toString();
        if (localeSuffix.length() > 0) {
            bundleName += "_" + localeSuffix;
        } else if (locale.getVariant().length() > 0) {
            //This corrects some strange behavior in Locale where
            //new Locale("", "", "VARIANT").toString == ""
            bundleName += "___" + locale.getVariant();
        }
        
        // The default locale may influence the lookup result, and
        // it may change, so we get it here once.
        Locale defaultLocale = Locale.getDefault();

        Object lookup = findBundleInCache(loader, bundleName, defaultLocale);
        if (lookup == NOT_FOUND) {
            throwMissingResourceException(baseName, locale);
        } else if (lookup != null) {
            return (ResourceBundle)lookup;
        }

        //The bundle was not cached, so start doing lookup at the root
        //Resources are loaded starting at the root and working toward
        //the requested bundle.

        //If findBundle returns null, we become responsible for defining
        //the bundle, and must call putBundleInCache to complete this
        //task.  This is critical because other threads may be waiting
        //for us to finish.

        Object parent = NOT_FOUND;
        try {
            //locate the root bundle and work toward the desired child
            Object root = findBundle(loader, baseName, defaultLocale, baseName, null);
            if (root == null) {
                putBundleInCache(loader, baseName, defaultLocale, NOT_FOUND);
                root = NOT_FOUND;
            }

            // Search the main branch of the search tree.
            // We need to keep references to the bundles we find on the main path
            // so they don't get garbage collected before we get to propagate().
            final Vector names = calculateBundleNames(baseName, locale);
            Vector bundlesFound = new Vector(MAX_BUNDLES_SEARCHED);
	    // if we found the root bundle and no other bundle names are needed
	    // we can stop here. We don't need to search or load anything further.
            boolean foundInMainBranch = (root != NOT_FOUND && names.size() == 0);
	    
	    if (!foundInMainBranch) {
	      parent = root;
	      for (int i = 0; i < names.size(); i++) {
                bundleName = (String)names.elementAt(i);
                lookup = findBundle(loader, bundleName, defaultLocale, baseName, parent);
                bundlesFound.addElement(lookup);
                if (lookup != null) {
                    parent = lookup;
                    foundInMainBranch = true;
                }
	      }
            }
            parent = root;
            if (!foundInMainBranch) {
                //we didn't find anything on the main branch, so we do the fallback branch
                final Vector fallbackNames = calculateBundleNames(baseName, defaultLocale);
                for (int i = 0; i < fallbackNames.size(); i++) {
                    bundleName = (String)fallbackNames.elementAt(i);
                    if (names.contains(bundleName)) {
                        //the fallback branch intersects the main branch so we can stop now.
                        break;
                    }
                    lookup = findBundle(loader, bundleName, defaultLocale, baseName, parent);
                    if (lookup != null) {
                        parent = lookup;
                    } else {
                        //propagate the parent to the child.  We can do this
                        //here because we are in the default path.
                        putBundleInCache(loader, bundleName, defaultLocale, parent);
                    }
                }
            }
            //propagate the inheritance/fallback down through the main branch
            parent = propagate(loader, names, bundlesFound, defaultLocale, parent);
        } catch (Exception e) {
            //We should never get here unless there has been a change
            //to the code that doesn't catch it's own exceptions.
            cleanUpConstructionList();
            throwMissingResourceException(baseName, locale);
        } catch (Error e) {
            //The only Error that can currently hit this code is a ThreadDeathError
            //but errors might be added in the future, so we'll play it safe and
            //clean up.
            cleanUpConstructionList();
            throw e;
        }
        if (parent == NOT_FOUND) {
            throwMissingResourceException(baseName, locale);
        }
        return (ResourceBundle)parent;
private static native java.lang.Class[]getClassContext()

public abstract java.util.EnumerationgetKeys()
Returns an enumeration of the keys.
private static java.lang.ClassLoadergetLoader()
        Class[] stack = getClassContext();
        /* Magic number 2 identifies our caller's caller */
        Class c = stack[2];
        ClassLoader cl = (c == null) ? null : c.getClassLoader();
        if (cl == null) {
            cl = ClassLoader.getSystemClassLoader();
        }
        return cl;
    
public java.util.LocalegetLocale()
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
        return locale;
    
public final java.lang.ObjectgetObject(java.lang.String 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 getObject method.
If still not successful, it throws a MissingResourceException.
param
key the key for the desired object
exception
NullPointerException if key is null
exception
MissingResourceException if no object for the given key can be found
return
the object for the given 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;
    
public final java.lang.StringgetString(java.lang.String key)
Gets a string for the given key from this resource bundle or one of its parents.
Calling this method is equivalent to calling


(String) {@link #getObject(java.lang.String) getObject}(key).

param
key the key for the desired string
exception
NullPointerException if key is null
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
        return (String) getObject(key);
    
public final java.lang.String[]getStringArray(java.lang.String 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


(String[]) {@link #getObject(java.lang.String) getObject}(key).

param
key the key for the desired string array
exception
NullPointerException if key is null
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
        return (String[]) getObject(key);
    
protected abstract java.lang.ObjecthandleGetObject(java.lang.String 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 key is null
return
the object for the given key, or null
private static java.lang.ObjectloadBundle(java.lang.ClassLoader loader, java.lang.String bundleName, java.util.Locale defaultLocale)
Load a bundle through either the specified ClassLoader or from a ".properties" file
and return the loaded bundle.
param
loader the ClassLoader to use to load the bundle. If null, the system
ClassLoader is used.
param
bundleName the name of the resource to load. The name should be complete
including a qualified class name followed by the locale extension.
ex. sun.text.resources.LocaleElements_fr_BE
param
defaultLocale the default locale at the time getBundle was called
return
the bundle or null if none could be found.
        // Search for class file using class loader
        try {
            Class bundleClass;
            if (loader != null) {
                bundleClass = loader.loadClass(bundleName);
            } else {
                bundleClass = Class.forName(bundleName);
            }
            if (ResourceBundle.class.isAssignableFrom(bundleClass)) {
                Object myBundle = bundleClass.newInstance();
                // Creating the instance may have triggered a recursive call to getBundle,
                // in which case the bundle created by the recursive call would be in the
                // cache now (4300693). For consistency, we'd then return the bundle from the cache.
                Object otherBundle = findBundleInCache(loader, bundleName, defaultLocale);
                if (otherBundle != null) {
                    return otherBundle;
                } else {
                    return myBundle;
                }
            }
        } catch (Exception e) {
        } catch (LinkageError e) {
        }

        // Next search for a Properties file.
        final String resName = bundleName.replace('.", '/") + ".properties";
        InputStream stream = (InputStream)java.security.AccessController.doPrivileged(
            new java.security.PrivilegedAction() {
                public Object run() {
                    if (loader != null) {
                        return loader.getResourceAsStream(resName);
                    } else {
                        return ClassLoader.getSystemResourceAsStream(resName);
                    }
                }
            }
        );

        if (stream != null) {
            // make sure it is buffered
            stream = new java.io.BufferedInputStream(stream);
            try {
                return new PropertyResourceBundle(stream);
            } catch (Exception e) {
            } finally {
                try {
                    stream.close();
                } catch (Exception e) {
                    // to avoid propagating an IOException back into the caller
                    // (I'm assuming this is never going to happen, and if it does,
                    // I'm obeying the precedent of swallowing exceptions set by the
                    // existing code above)
                }
            }
        }
        return null;
    
private static java.lang.Objectpropagate(java.lang.ClassLoader loader, java.util.Vector names, java.util.Vector bundlesFound, java.util.Locale defaultLocale, java.lang.Object parent)
propagate bundles from the root down the specified branch of the search tree.
param
loader the class loader for the bundles
param
names the names of the bundles along search path
param
bundlesFound the bundles corresponding to the names (some may be null)
param
defaultLocale the default locale at the time getBundle was called
param
parent the parent of the first bundle in the path (the root bundle)
return
the value of the last bundle along the path
        for (int i = 0; i < names.size(); i++) {
            final String bundleName = (String)names.elementAt(i);
            final Object lookup = bundlesFound.elementAt(i);
            if (lookup == null) {
                putBundleInCache(loader, bundleName, defaultLocale, parent);
            } else {
                parent = lookup;
            }
        }
        return parent;
    
private static voidputBundleInCache(java.lang.ClassLoader loader, java.lang.String bundleName, java.util.Locale defaultLocale, java.lang.Object value)
Put a new bundle in the cache and notify waiting threads that a new
bundle has been put in the cache.
param
defaultLocale the default locale at the time getBundle was called
        //we use a static shared cacheKey but we use the lock in cacheList since
        //the key is only used to interact with cacheList.
        synchronized (cacheList) {
            cacheKey.setKeyValues(loader, bundleName, defaultLocale);
            cacheList.put(cacheKey.clone(), value);
            underConstruction.remove(cacheKey);
            cacheKey.clear();
            //notify waiters that we're done constructing the bundle
            cacheList.notifyAll();
        }
    
private voidsetLocale(java.lang.String baseName, java.lang.String bundleName)
Sets the locale for this bundle. This is the locale that this
bundle actually represents and does not depend on how the
bundle was found by getBundle. Ex. if the user was looking
for fr_FR and getBundle found en_US, the bundle's locale would
be en_US, NOT fr_FR
param
baseName the bundle's base name
param
bundleName the complete bundle name including locale
extension.
        if (baseName.length() == bundleName.length()) {
            locale = new Locale("", "");
        } else if (baseName.length() < bundleName.length()) {
            int pos = baseName.length();
            String temp = bundleName.substring(pos + 1);
            pos = temp.indexOf('_");
            if (pos == -1) {
                locale = new Locale(temp, "", "");
                return;
            }

            String language = temp.substring(0, pos);
            temp = temp.substring(pos + 1);
            pos = temp.indexOf('_");
            if (pos == -1) {
                locale = new Locale(language, temp, "");
                return;
            }

            String country = temp.substring(0, pos);
            temp = temp.substring(pos + 1);

            locale = new Locale(language, country, temp);
        } else {
            //The base name is longer than the bundle name.  Something is very wrong
            //with the calling code.
            throw new IllegalArgumentException();
        }
    
protected voidsetParent(java.util.ResourceBundle parent)
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.
        this.parent = parent;
    
private static voidthrowMissingResourceException(java.lang.String baseName, java.util.Locale locale)
Throw a MissingResourceException with proper message
        throw new MissingResourceException("Can't find bundle for base name "
                                           + baseName + ", locale " + locale,
                                           baseName + "_" + locale,"");