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: *
* 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 {
* 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
* };
* }
* }
*
*
* 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 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().
*
*
getBundle
* factory methods that take a ResourceBundle.Control
* 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.
*
* getBundle factory
* methods are cached by default, and the factory methods return the same
* resource bundle instance multiple times if it has been
* cached. getBundle 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) getBundle 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.
*
* ResourceBundle
* subclass, MyResources, that manages two resources (for a larger number of
* resources you would probably use a Map).
* 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).
*
*
* // 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"));
* }
* }
*
*
* 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
*/
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) {@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
*/
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
*
* (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
*/
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 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
*/
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
* getBundle(baseName, Locale.getDefault(), this.getClass().getClassLoader()),
*
* except that getClassLoader() is run with the security
* privileges of ResourceBundle.
* 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 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
*/
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
*
* getBundle(baseName, Locale.getDefault(),
* this.getClass().getClassLoader(), control),
*
* except that getClassLoader() is run with the security
* privileges of ResourceBundle. See {@link
* #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
* complete description of the resource bundle loading process with a
* ResourceBundle.Control.
*
* @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 baseName or control is
* null
* @exception MissingResourceException
* if no resource bundle for the specified base name can be found
* @exception IllegalArgumentException
* if the given control doesn't perform properly
* (e.g., control.getCandidateLocales returns null.)
* Note that validation of control 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
*
* getBundle(baseName, locale, this.getClass().getClassLoader()),
*
* except that getClassLoader() is run with the security
* privileges of ResourceBundle.
* 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 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
*/
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
*
* getBundle(baseName, targetLocale, this.getClass().getClassLoader(),
* control),
*
* except that getClassLoader() is run with the security
* privileges of ResourceBundle. See {@link
* #getBundle(String, Locale, ClassLoader, Control) getBundle} for the
* complete description of the resource bundle loading process with a
* ResourceBundle.Control.
*
* @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
* Locale in locales
* @exception NullPointerException
* if baseName, locales or
* control is null
* @exception MissingResourceException
* if no resource bundle for the specified base name in any
* of the locales can be found.
* @exception IllegalArgumentException
* if the given control doesn't perform properly
* (e.g., control.getCandidateLocales returns null.)
* Note that validation of control 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.
*
* This method behaves the same as calling * {@link #getBundle(String, Locale, ClassLoader, Control)} passing a * default instance of {@link Control}. The following describes this behavior. * *
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, script, country, and variant are all empty strings,
* then the base name is the only candidate bundle name. Otherwise, a list
* of candidate locales is generated from the attribute values of the
* specified locale (language, script, country and variant) and appended to
* the base name. Typically, this will look like the following:
*
*
* baseName + "_" + language + "_" + script + "_" + country + "_" + variant
* baseName + "_" + language + "_" + script + "_" + country
* baseName + "_" + language + "_" + script
* baseName + "_" + language + "_" + country + "_" + variant
* baseName + "_" + language + "_" + country
* baseName + "_" + language
*
*
* Candidate bundle names where the final component is an empty string * are omitted, along with the underscore. For example, if country is an * empty string, the second and the fifth candidate bundle names above * would be omitted. Also, if script is an empty string, the candidate names * including script are omitted. For example, a locale with language "de" * and variant "JAVA" will produce candidate names with base name * "MyResource" below. * *
* MyResource_de__JAVA
* MyResource_de
*
*
* In the case that the variant contains one or more underscores ('_'), a
* sequence of bundle names generated by truncating the last underscore and
* the part following it is inserted after a candidate bundle name with the
* original variant. For example, for a locale with language "en", script
* "Latn, country "US" and variant "WINDOWS_VISTA", and bundle base name
* "MyResource", the list of candidate bundle names below is generated:
*
*
* MyResource_en_Latn_US_WINDOWS_VISTA
* MyResource_en_Latn_US_WINDOWS
* MyResource_en_Latn_US
* MyResource_en_Latn
* MyResource_en_US_WINDOWS_VISTA
* MyResource_en_US_WINDOWS
* MyResource_en_US
* MyResource_en
*
*
* Note: For some Locales, the list of
* candidate bundle names contains extra names, or the order of bundle names
* is slightly modified. See the description of the default implementation
* of {@link Control#getCandidateLocales(String, Locale)
* getCandidateLocales} for details.
*
* getBundle then iterates over the candidate bundle names
* to find the first one for which it can instantiate an actual
* resource bundle. It uses the default controls' {@link Control#getFormats
* getFormats} method, which generates two bundle names for each generated
* name, the first a class name and the second a properties file name. For
* each candidate bundle name, it attempts to create a resource bundle:
*
*
getBundle creates a
* new instance of this class and uses it as the result resource
* bundle.
*
* getBundle attempts to locate a property
* resource file using the generated properties file name. 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. This continues until a result resource bundle is instantiated or the * list of candidate bundle names is exhausted. If no matching resource * bundle is found, the default control's {@link Control#getFallbackLocale * getFallbackLocale} method is called, which returns the current default * locale. A new sequence of candidate locale names is generated using this * locale and and searched again, as above. * *
If still no result bundle is found, the base name alone is looked up. If
* this still fails, a MissingResourceException is thrown.
*
*
Once a result resource bundle has been found, * its parent chain is instantiated. If the result bundle already * has a parent (perhaps because it was returned from a cache) the chain is * complete. * *
Otherwise, getBundle examines the remainder of the
* candidate locale list that was used during the pass that generated the
* result resource bundle. (As before, candidate bundle names where the
* final component is an empty string are omitted.) When it comes to the
* end of the candidate list, it tries the plain bundle name. With each of the
* candidate bundle names it attempts to instantiate a resource bundle (first
* looking for a class and then a properties file, 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. This continues until the list of names * is exhausted or the current bundle already has a non-null parent. * *
Once the parent chain is complete, the bundle is returned. * *
Note: getBundle caches instantiated resource
* bundles and might return the same resource bundle instance multiple times.
*
*
Note:The baseName 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 PropertyResourceBundles by specifying a
* path name (using "/") instead of a fully qualified class name (using
* ".").
*
*
* The following class and property files are provided: *
* MyResources.class
* MyResources.properties
* MyResources_fr.properties
* MyResources_fr_CH.class
* MyResources_fr_CH.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 locale arguments below will
* instantiate resource bundles as follows:
*
*
| Locale("fr", "CH") | MyResources_fr_CH.class, parent MyResources_fr.properties, parent MyResources.class |
| Locale("fr", "FR") | MyResources_fr.properties, parent MyResources.class |
| Locale("de", "DE") | MyResources_en.properties, parent MyResources.class |
| Locale("en", "US") | MyResources_en.properties, parent MyResources.class |
| Locale("es", "ES") | MyResources_es_ES.class, parent MyResources.class |
The file MyResources_fr_CH.properties is never used because it is
* hidden by the 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 baseName, locale, or loader is null
* @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) getBundle
* factory methods with no control argument}, the given
* control specifies how to locate and instantiate resource
* bundles. Conceptually, the bundle loading process with the given
* control is performed in the following steps.
*
*
*
baseName, targetLocale and
* loader. 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."java.class" and "java.properties"
* designate class-based and {@linkplain PropertyResourceBundle
* property}-based resource bundles, respectively. Other strings
* starting with "java." are reserved for future extensions
* and must not be used for application-defined formats. Other strings
* designate application-defined formats.Locales for
* which resource bundles are searched.ResourceBundle 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 newBundle method
* returns a ResourceBundle instance or the iteration has
* used up all the combinations. For example, if the candidate locales
* are Locale("de", "DE"), Locale("de") and
* Locale("") and the formats are "java.class"
* and "java.properties", then the following is the
* sequence of locale-format combinations to be used to call
* control.newBundle.
*
* | Locale * |
* format * |
*
| Locale("de", "DE") * |
* java.class * |
*
| Locale("de", "DE") | *java.properties * |
*
| Locale("de") | *java.class | *
| Locale("de") | *java.properties | *
| Locale("") * |
* java.class | *
| Locale("") | *java.properties | *
Locale("")), and the candidate locale list only contained
* Locale(""), 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.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
* control.newBundle to reload the resource bundle. If
* control.newBundle returns null, 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 control.
*
*
All resource bundles loaded are cached by default. Refer to * {@link Control#getTimeToLive(String,Locale) * control.getTimeToLive} for details. * *
The following is an example of the bundle loading process with the
* default ResourceBundle.Control implementation.
*
*
Conditions: *
foo.bar.Messages
* Locale: {@link Locale#ITALY}Locale: {@link Locale#FRENCH}foo/bar/Messages_fr.properties and
* foo/bar/Messages.propertiesFirst, getBundle tries loading a resource bundle in
* the following sequence.
*
*
foo.bar.Messages_it_IT
* foo/bar/Messages_it_IT.properties
* foo.bar.Messages_itfoo/bar/Messages_it.propertiesfoo.bar.Messagesfoo/bar/Messages.propertiesAt this point, getBundle finds
* foo/bar/Messages.properties, which is put on hold
* because it's the base bundle. getBundle calls {@link
* Control#getFallbackLocale(String, Locale)
* control.getFallbackLocale("foo.bar.Messages", Locale.ITALY)} which
* returns Locale.FRENCH. Next, getBundle
* tries loading a bundle in the following sequence.
*
*
foo.bar.Messages_frfoo/bar/Messages_fr.propertiesfoo.bar.Messagesfoo/bar/Messages.propertiesThe default implementation returns a 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 Two factory methods, {@link #getControl(List)} and {@link
* #getNoFallbackControl(List)}, provide
* 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
* A Applications can specify Example 1
*
* The following code lets Example 2
*
* The following is an example of loading XML-based bundles
* using {@link Properties#loadFromXML(java.io.InputStream)
* Properties.loadFromXML}.
*
* Specifying {@link Control#FORMAT_DEFAULT} is equivalent to
* instantiating the It is not a requirement to return an immutable (unmodifiable)
* The default implementation returns {@link #FORMAT_DEFAULT} so
* that the The sequence of the candidate locales also corresponds to the
* runtime resource lookup path (also known as the parent
* chain), 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.
*
* If the given locale is equal to It is not a requirement to return an immutable (unmodifiable)
* The default implementation returns a Also, Java treats the language "no" as a synonym of Norwegian
* Bokmål "nb". Except for the single case 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 For example, if the given The method returns The default implementation returns the {@linkplain
* Locale#getDefault() default If the The default implementation instantiates a
* The expiration affects only the bundle loading process by the
* 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.
*
* 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 The default implementation compares This implementation returns the following value:
* For example, if 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 getBundle finds
* foo/bar/Messages_fr.properties and creates a
* ResourceBundle instance. Then, getBundle
* sets up its parent chain from the list of the candiate locales. Only
* foo/bar/Messages.properties is found in the list and
* getBundle creates a ResourceBundle instance
* that becomes the parent of the instance for
* foo/bar/Messages_fr.properties.
*
* @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 baseName, targetLocale,
* loader, or control is
* null
* @exception MissingResourceException
* if no resource bundle for the specified base name can be found
* @exception IllegalArgumentException
* if the given control doesn't perform properly
* (e.g., control.getCandidateLocales returns null.)
* Note that validation of control 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);
ListList 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,
Listbundle.expire 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 loader is null
* @since 1.6
* @see ResourceBundle.Control#getTimeToLive(String,Locale)
*/
public static final void clearCache(ClassLoader loader) {
if (loader == null) {
throw new NullPointerException();
}
Setkey is null
* @return the object for the given key, or null
*/
protected abstract Object handleGetObject(String key);
/**
* Returns an enumeration of the keys.
*
* @return an Enumeration of the keys contained in
* this ResourceBundle and its parent bundles.
*/
public abstract Enumerationkey is contained in
* this ResourceBundle or its parent bundles.
*
* @param key
* the resource key
* @return true if the given key is
* contained in this ResourceBundle or its
* parent bundles; false otherwise.
* @exception NullPointerException
* if key is null
* @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 Set of all keys contained in this
* ResourceBundle and its parent bundles.
*
* @return a Set of all keys contained in this
* ResourceBundle and its parent bundles.
* @since 1.6
*/
public SetSet of the keys contained only
* in this ResourceBundle.
*
* Set of the
* keys returned by the {@link #getKeys() getKeys} method except
* for the ones for which the {@link #handleGetObject(String)
* handleGetObject} method returns null. Once the
* Set has been created, the value is kept in this
* ResourceBundle in order to avoid producing the
* same Set in subsequent calls. Subclasses can
* override this method for faster handling.
*
* @return a Set of the keys contained only in this
* ResourceBundle
* @since 1.6
*/
protected SetResourceBundle.Control 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
* ResourceBundle.Control 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 default behavior.
*
* toBundleName method could be
* overridden to provide different conventions in the organization and
* packaging of localized resources. The toResourceName
* method is final to avoid use of wrong resource and class
* name separators.
*
* ResourceBundle.Control instances that implement common
* variations of the default bundle loading process.
*
* ResourceBundle.getBundle invocations for the same base
* bundle. Otherwise, the ResourceBundle.getBundle methods
* may return unintended bundles. For example, if only
* "java.class" is returned by the getFormats
* method for the first call to ResourceBundle.getBundle
* and only "java.properties" for the second call, then the
* second call will return the class-based one that has been cached
* during the first call.
*
* ResourceBundle.Control instance must be thread-safe
* if it's simultaneously used by multiple threads.
* ResourceBundle.getBundle does not synchronize to call
* the ResourceBundle.Control methods. The default
* implementations of the methods are thread-safe.
*
* ResourceBundle.Control
* instances returned by the getControl factory methods or
* created from a subclass of ResourceBundle.Control to
* customize the bundle loading process. The following are examples of
* changing the default bundle loading process.
*
* ResourceBundle.getBundle look
* up only properties-based resources.
*
*
* import java.util.*;
* import static java.util.ResourceBundle.Control.*;
* ...
* ResourceBundle bundle =
* ResourceBundle.getBundle("MyResources", new Locale("fr", "CH"),
* ResourceBundle.Control.getControl(FORMAT_PROPERTIES));
*
*
* Given the resource bundles in the example in
* the ResourceBundle.getBundle description, this
* ResourceBundle.getBundle call loads
* MyResources_fr_CH.properties whose parent is
* MyResources_fr.properties whose parent is
* MyResources.properties. (MyResources_fr_CH.properties
* is not hidden, but MyResources_fr_CH.class is.)
*
*
* 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() {
* ...
* }
* }
*
*
* @since 1.6
*/
public static class Control {
/**
* The default format List, which contains the strings
* "java.class" and "java.properties", in
* this order. This List is {@linkplain
* Collections#unmodifiableList(List) unmodifiable}.
*
* @see #getFormats(String)
*/
public static final ListList containing
* "java.class". This List is {@linkplain
* Collections#unmodifiableList(List) unmodifiable}.
*
* @see #getFormats(String)
*/
public static final ListList containing
* "java.properties". This List is
* {@linkplain Collections#unmodifiableList(List) unmodifiable}.
*
* @see #getFormats(String)
*/
public static final ListResourceBundle.Control in which the {@link
* #getFormats(String) getFormats} method returns the specified
* formats. The formats must be equal to
* one of {@link Control#FORMAT_PROPERTIES}, {@link
* Control#FORMAT_CLASS} or {@link
* Control#FORMAT_DEFAULT}. ResourceBundle.Control
* instances returned by this method are singletons and thread-safe.
*
* ResourceBundle.Control class,
* except that this method returns a singleton.
*
* @param formats
* the formats to be returned by the
* ResourceBundle.Control.getFormats method
* @return a ResourceBundle.Control supporting the
* specified formats
* @exception NullPointerException
* if formats is null
* @exception IllegalArgumentException
* if formats is unknown
*/
public static final Control getControl(ListResourceBundle.Control in which the {@link
* #getFormats(String) getFormats} method returns the specified
* formats and the {@link
* Control#getFallbackLocale(String, Locale) getFallbackLocale}
* method returns null. The formats must
* be equal to one of {@link Control#FORMAT_PROPERTIES}, {@link
* Control#FORMAT_CLASS} or {@link Control#FORMAT_DEFAULT}.
* ResourceBundle.Control instances returned by this
* method are singletons and thread-safe.
*
* @param formats
* the formats to be returned by the
* ResourceBundle.Control.getFormats method
* @return a ResourceBundle.Control supporting the
* specified formats with no fallback
* Locale support
* @exception NullPointerException
* if formats is null
* @exception IllegalArgumentException
* if formats is unknown
*/
public static final Control getNoFallbackControl(ListList of Strings containing
* formats to be used to load resource bundles for the given
* baseName. The ResourceBundle.getBundle
* 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 String. The predefined
* formats are "java.class" for class-based resource
* bundles and "java.properties" for {@linkplain
* PropertyResourceBundle properties-based} ones. Strings starting
* with "java." are reserved for future extensions and
* must not be used by application-defined formats.
*
* List. However, the returned List must
* not be mutated after it has been returned by
* getFormats.
*
* ResourceBundle.getBundle 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 List of Strings containing
* formats for loading resource bundles.
* @exception NullPointerException
* if baseName is null
* @see #FORMAT_DEFAULT
* @see #FORMAT_CLASS
* @see #FORMAT_PROPERTIES
*/
public ListList of Locales as candidate
* locales for baseName and locale. This
* method is called by the ResourceBundle.getBundle
* factory method each time the factory method tries finding a
* resource bundle for a target Locale.
*
* Locale.ROOT (the
* root locale), a List containing only the root
* Locale must be returned. In this case, the
* ResourceBundle.getBundle factory method loads only
* the base bundle as the resulting resource bundle.
*
* List. However, the returned List must not
* be mutated after it has been returned by
* getCandidateLocales.
*
* List containing
* Locales using the rules described below. In the
* description below, L, S, C and V
* respectively represent non-empty language, script, country, and
* variant. For example, [L, C] represents a
* Locale that has non-empty values only for language and
* country. The form L("xx") represents the (non-empty)
* language value is "xx". For all cases, Locales whose
* final component values are empty strings are omitted.
*
*
*
* Locale with an empty script value,
* append candidate Locales by omitting the final component
* one by one as below:
*
*
*
*
* Locale.ROOT
* Locale with a non-empty script value,
* append candidate Locales by omitting the final component
* up to language, then append candidates generated from the
* Locale with country and variant restored:
*
*
*
*
* Locale.ROOT
* Locale with a variant value consisting
* of multiple subtags separated by underscore, generate candidate
* Locales by omitting the variant subtags one by one, then
* insert them after every occurence of Locales with the
* full variant value in the original list. For example, if the
* the variant consists of two subtags V1 and V2:
*
*
*
*
* Locale.ROOT
* Locale has the
* language "zh" (Chinese) and an empty script value, either "Hans" (Simplified) or
* "Hant" (Traditional) might be supplied, depending on the country.
* When the country is "CN" (China) or "SG" (Singapore), "Hans" is supplied.
* When the country is "HK" (Hong Kong SAR China), "MO" (Macau SAR China),
* or "TW" (Taiwan), "Hant" is supplied. For all other countries or when the country
* is empty, no script is supplied. For example, for Locale("zh", "CN")
* , the candidate list will be:
*
*
*
* For Locale.ROOT
* Locale("zh", "TW"), the candidate list will be:
*
*
*
* Locale.ROOT
* Locale("no", "NO",
* "NY") and Locale("nn", "NO") represent Norwegian
* Nynorsk. When a locale's language is "nn", the standard candidate
* list is generated up to [L("nn")], and then the following
* candidates are added:
*
*
*
* If the locale is exactly Locale.ROOT
* Locale("no", "NO", "NY"), it is first
* converted to Locale("nn", "NO") and then the above procedure is
* followed.
*
* Locale("no",
* "NO", "NY") (handled above), when an input Locale
* has language "no" or "nb", candidate Locales with
* language code "no" and "nb" are interleaved, first using the
* requested language, then using its synonym. For example,
* Locale("nb", "NO", "POSIX") generates the following
* candidate list:
*
*
*
*
* Locale.ROOT
* Locale("no", "NO", "POSIX") would generate the same list
* except that locales with "no" would appear before the corresponding
* locales with "nb".getCandidateLocales.
*
* baseName is "Messages"
* and the given locale is
* Locale("ja", "", "XX"), then a
* List of Locales:
*
* Locale("ja", "", "XX")
* Locale("ja")
* Locale.ROOT
*
* is returned. And if the resource bundles for the "ja" and
* "" Locales are found, then the runtime resource
* lookup path (parent chain) is:
*
* Messages_ja -> Messages
*
*
* @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 List of candidate
* Locales for the given locale
* @exception NullPointerException
* if baseName or locale is
* null
*/
public ListLocale to be used as a fallback locale for
* further resource bundle searches by the
* ResourceBundle.getBundle factory method. This method
* is called from the factory method every time when no resulting
* resource bundle has been found for baseName and
* locale, where locale is either the parameter for
* ResourceBundle.getBundle or the previous fallback
* locale returned by this method.
*
* null if no further fallback
* search is desired.
*
* Locale} if the given
* locale isn't the default one. Otherwise,
* null is returned.
*
* @param baseName
* the base name of the resource bundle, a fully
* qualified class name for which
* ResourceBundle.getBundle has been
* unable to find any resource bundles (except for the
* base bundle)
* @param locale
* the Locale for which
* ResourceBundle.getBundle has been
* unable to find any resource bundles (except for the
* base bundle)
* @return a Locale for the fallback search,
* or null if no further fallback search
* is desired.
* @exception NullPointerException
* if baseName or locale
* is null
*/
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 null 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 Error or
* Exception rather than simply returning
* null.
*
* reload flag is true, it
* indicates that this method is being called because the previously
* loaded resource bundle has expired.
*
* ResourceBundle as follows.
*
*
*
*
*
* @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 format is "java.class", the
* {@link Class} specified by the bundle name is loaded by calling
* {@link ClassLoader#loadClass(String)}. Then, a
* ResourceBundle is instantiated by calling {@link
* Class#newInstance()}. Note that the reload flag is
* ignored for loading class-based resource bundles in this default
* implementation.format is "java.properties",
* {@link #toResourceName(String, String) toResourceName(bundlename,
* "properties")} is called to get the resource name.
* If reload is true, {@link
* ClassLoader#getResource(String) load.getResource} is called
* to get a {@link URL} for creating a {@link
* URLConnection}. This URLConnection is used to
* {@linkplain URLConnection#setUseCaches(boolean) disable the
* caches} of the underlying resource loading layers,
* and to {@linkplain URLConnection#getInputStream() get an
* InputStream}.
* Otherwise, {@link ClassLoader#getResourceAsStream(String)
* loader.getResourceAsStream} is called to get an {@link
* InputStream}. Then, a {@link
* PropertyResourceBundle} is constructed with the
* InputStream.format is neither "java.class"
* nor "java.properties", an
* IllegalArgumentException is thrown.ClassLoader to use to load the bundle
* @param reload
* the flag to indicate bundle reloading; true
* if reloading an expired resource bundle,
* false otherwise
* @return the resource bundle instance,
* or null if none could be found.
* @exception NullPointerException
* if bundleName, locale,
* format, or loader is
* null, or if null is returned by
* {@link #toBundleName(String, Locale) toBundleName}
* @exception IllegalArgumentException
* if format is unknown, or if the resource
* found for the given parameters contains malformed data.
* @exception ClassCastException
* if the loaded class cannot be cast to ResourceBundle
* @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 bundleClass
= (Class)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 PrivilegedExceptionActionResourceBundle.Control. 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.
*
* ResourceBundle.getBundle 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 needsReload returns
* true, 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.
*
* baseName or locale is
* null
*/
public long getTimeToLive(String baseName, Locale locale) {
if (baseName == null || locale == null) {
throw new NullPointerException();
}
return TTL_NO_EXPIRATION_CONTROL;
}
/**
* Determines if the expired bundle in the cache needs
* to be reloaded based on the loading time given by
* loadTime or some other criteria. The method returns
* true if reloading is required; false
* otherwise. loadTime is a millisecond offset since
* the Calendar
* Epoch.
*
* The calling ResourceBundle.getBundle factory method
* calls this method on the ResourceBundle.Control
* instance used for its current invocation, not on the instance
* used in the invocation that originally loaded the resource
* bundle.
*
* loadTime 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 loadTime, true is
* returned. Otherwise, false is returned. This
* implementation assumes that the given format is the
* same string as its file suffix if it's not one of the default
* formats, "java.class" or
* "java.properties".
*
* @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 ClassLoader to use to load the bundle
* @param bundle
* the resource bundle instance that has been expired
* in the cache
* @param loadTime
* the time when bundle was loaded and put
* in the cache
* @return true if the expired bundle needs to be
* reloaded; false otherwise.
* @exception NullPointerException
* if baseName, locale,
* format, loader, or
* bundle is null
*/
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 baseName and locale
* 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.
*
*
* baseName + "_" + language + "_" + script + "_" + country + "_" + variant
*
* where language, script, country,
* and variant are the language, script, country, and variant
* values of locale, respectively. Final component values that
* are empty Strings are omitted along with the preceding '_'. When the
* script is empty, the script value is ommitted along with the preceding '_'.
* If all of the values are empty strings, then baseName
* is returned.
*
* baseName is
* "baseName" and locale is
* Locale("ja", "", "XX"), then
* "baseName_ja_ _XX" is returned. If the given
* locale is Locale("en"), then
* "baseName_en" is returned.
*
* baseName or locale
* is null
*/
public String toBundleName(String baseName, Locale locale) {
if (locale == Locale.ROOT) {
return baseName;
}
String language = locale.getLanguage();
String script = locale.getScript();
String country = locale.getCountry();
String variant = locale.getVariant();
if (language == "" && country == "" && variant == "") {
return baseName;
}
StringBuilder sb = new StringBuilder(baseName);
sb.append('_');
if (script != "") {
if (variant != "") {
sb.append(language).append('_').append(script).append('_').append(country).append('_').append(variant);
} else if (country != "") {
sb.append(language).append('_').append(script).append('_').append(country);
} else {
sb.append(language).append('_').append(script);
}
} else {
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 bundleName to the form required
* by the {@link ClassLoader#getResource ClassLoader.getResource}
* method by replacing all occurrences of '.' in
* bundleName with '/' and appending a
* '.' and the given file suffix. For
* example, if bundleName is
* "foo.bar.MyResources_ja_JP" and suffix
* is "properties", then
* "foo/bar/MyResources_ja_JP.properties" is returned.
*
* @param bundleName
* the bundle name
* @param suffix
* the file type suffix
* @return the converted resource name
* @exception NullPointerException
* if bundleName or suffix
* is null
*/
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