java.util.ResourceBundle
is new.
java.lang.Object
public abstract class ResourceBundle
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:
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 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 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().
ResourceBundle.Control
The
ResourceBundle.Control
class provides information necessary to perform the bundle loading process by the 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
getBundle
factory method for details.
Cache Management
Resource bundle instances created by the 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
getBundle factory method
,
clearCache
,
ResourceBundle.Control.getTimeToLive
, and
ResourceBundle.Control.needsReload
for details.
Example
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 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;
}
}
// 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.
Since:
JDK1.1
See Also:
ListResourceBundle
,
PropertyResourceBundle
,
MissingResourceException
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Nested Class Summary
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static class
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ResourceBundle.Control
ResourceBundle.Control defines a set of callback methods that are invoked by the
ResourceBundle.getBundle
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Field Summary
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protected
ResourceBundle
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parent
The parent bundle of this bundle.
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Constructor Summary
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ResourceBundle
()
Sole constructor.
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Method Summary
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static void
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clearCache
()
Removes all resource bundles from the cache that have been loaded using the caller's class loader.
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static void
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clearCache
(
ClassLoader
Removes all resource bundles from the cache that have been loaded using the given class loader.
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boolean
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containsKey
(
String
Determines whether the given key is contained in this ResourceBundle or its parent bundles.
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static
ResourceBundle
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getBundle
(
String
Gets a resource bundle using the specified base name, the default locale, and the caller's class loader.
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static
ResourceBundle
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getBundle
(
String
baseName,
Locale
Gets a resource bundle using the specified base name and locale, and the caller's class loader.
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static
ResourceBundle
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getBundle
(
String
baseName,
Locale
locale,
ClassLoader
Gets a resource bundle using the specified base name, locale, and class loader.
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static
ResourceBundle
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getBundle
(
String
baseName,
Locale
targetLocale,
ClassLoader
loader,
ResourceBundle.Control
Returns a resource bundle using the specified base name, target locale, class loader and control.
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static
ResourceBundle
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getBundle
(
String
baseName,
Locale
targetLocale,
ResourceBundle.Control
Returns a resource bundle using the specified base name, target locale and control, and the caller's class loader.
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static
ResourceBundle
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getBundle
(
String
baseName,
ResourceBundle.Control
Returns a resource bundle using the specified base name, the default locale and the specified control.
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abstract
Enumeration
<
String
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getKeys
()
Returns an enumeration of the keys.
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Locale
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getLocale
()
Returns the locale of this resource bundle.
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Object
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getObject
(
String
Gets an object for the given key from this resource bundle or one of its parents.
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String
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getString
(
String
Gets a string for the given key from this resource bundle or one of its parents.
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String
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getStringArray
(
String
Gets a string array for the given key from this resource bundle or one of its parents.
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protected abstract
Object
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handleGetObject
(
String
Gets an object for the given key from this resource bundle.
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protected
Set
<
String
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handleKeySet
()
Returns a Set of the keys contained only in this ResourceBundle.
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Set
<
String
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keySet
()
Returns a Set of all keys contained in this ResourceBundle and its parent bundles.
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protected void
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setParent
(
ResourceBundle
Sets the parent bundle of this bundle.
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Methods inherited from class java.lang.
Object
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clone
,
equals
,
finalize
,
getClass
,
hashCode
,
notify
,
notifyAll
,
toString
,
wait
,
wait
,
wait
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Field Detail
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parent
The parent bundle of this bundle. The parent bundle is searched by
getObject
when this bundle does not contain a particular resource.
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Constructor Detail
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ResourceBundle
Sole constructor. (For invocation by subclass constructors, typically implicit.)
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Method Detail
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getString
Gets a string for the given key from this resource bundle or one of its parents. Calling this method is equivalent to calling
Parameters:
key - the key for the desired string
Returns:
the string for the given key
Throws:
NullPointerException
- if key is null
MissingResourceException
- if no object for the given key can be found
ClassCastException
- if the object found for the given key is not a string
getStringArray
Gets a string array for the given key from this resource bundle or one of its parents. Calling this method is equivalent to calling
Parameters:
key - the key for the desired string array
Returns:
the string array for the given key
Throws:
NullPointerException
- if key is null
MissingResourceException
- if no object for the given key can be found
ClassCastException
- if the object found for the given key is not a string array
getObject
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
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.
Parameters:
key - the key for the desired object
Returns:
the object for the given key
Throws:
NullPointerException
- if key is null
MissingResourceException
- if no object for the given key can be found
getLocale
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.
Returns:
the locale of this resource bundle
setParent
Sets the parent bundle of this bundle. The parent bundle is searched by
getObject
when this bundle does not contain a particular resource.
Parameters:
parent - this bundle's parent bundle.
getBundle
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
except that getClassLoader() is run with the security privileges of ResourceBundle. See
getBundle
for a complete description of the search and instantiation strategy.
Parameters:
baseName - the base name of the resource bundle, a fully qualified class name
Returns:
a resource bundle for the given base name and the default locale
Throws:
NullPointerException
- if baseName is null
MissingResourceException
- if no resource bundle for the specified base name can be found
getBundle
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
getBundle
for the complete description of the resource bundle loading process with a ResourceBundle.Control.
Parameters:
baseName - the base name of the resource bundle, a fully qualified class name
control - the control which gives information for the resource bundle loading process
Returns:
a resource bundle for the given base name and the default locale
Throws:
NullPointerException
- if baseName or control is null
MissingResourceException
- if no resource bundle for the specified base name can be found
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
getBundle
Gets a resource bundle using the specified base name and locale, and the caller's class loader. Calling this method is equivalent to calling
except that getClassLoader() is run with the security privileges of ResourceBundle. See
getBundle
for a complete description of the search and instantiation strategy.
Parameters:
baseName - the base name of the resource bundle, a fully qualified class name
locale - the locale for which a resource bundle is desired
Returns:
a resource bundle for the given base name and locale
Throws:
NullPointerException
- if baseName or locale is null
MissingResourceException
- if no resource bundle for the specified base name can be found
getBundle
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
getBundle
for the complete description of the resource bundle loading process with a ResourceBundle.Control.
Parameters:
baseName - the base name of the resource bundle, a fully qualified class name
targetLocale - the locale for which a resource bundle is desired
control - the control which gives information for the resource bundle loading process
Returns:
a resource bundle for the given base name and a Locale in locales
Throws:
NullPointerException
- if baseName, locales or control is null
MissingResourceException
- if no resource bundle for the specified base name in any of the locales can be found.
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
getBundle
Gets a resource bundle using the specified base name, locale, and class loader.
getBundle uses the base name, the specified locale, and the default locale (obtained from
Locale.getDefault
Conceptually, getBundle uses the following strategy for locating and instantiating resource bundles:
) 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
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
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
setParent
method with the new resource bundle, unless the previously instantiated resource bundle already has a non-null parent.
getBundle caches instantiated resource bundles and may return the same resource bundle instance multiple times.
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 ".").
Code assignments in ISO 639 have changed over time for a few languages. When the locale (either the specified one or the default) uses one of the languages where a new language code replaced an old one, the default implementation of getBundle instantiates resource bundles with candidate bundle names with both old and new language codes, using the locale's language code first. For example, the table below shows the candidate bundle names generated for three request locales involving Hebrew; the same pattern is used for Indonesian and Yiddish.
For Norwegian, ISO 639 added two new specialized language codes in addition to an older, more generic one. The table shows the candidate bundle names generated for the locales involving either of the language codes.
ResourceBundle myResources = ResourceBundle.getBundle("MyResources", currentLocale);
Calling getBundle with the shown locale argument values instantiates resource bundles from the following sources:
The file MyResources_fr_CH.properties is never used because it is hidden by MyResources_fr_CH.class. Likewise, MyResources.properties is also hidden by MyResources.class.
Example:
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").
- if baseName, locale, or loader is null
MissingResourceException
- if no resource bundle for the specified base name can be found
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 }; }
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"));
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; } }
1.2
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getBundle
protectedResourceBundleparent
Returns a resource bundle using the specified base name, target locale, class loader and control. Unlike the
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.
This factory method looks up the resource bundle in the cache for the specified 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.
The
control.getFormats
method is called to get resource bundle formats to produce bundle or resource names. The strings "java.class" and "java.properties" designate class-based and
property
The
control.getCandidateLocales
The
control.newBundle
|
Locale
|
format
|
|
Locale("de", "DE")
|
java.class
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Locale("de", "DE")
|
java.properties
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Locale("de")
|
java.class
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Locale("de")
|
java.properties
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Locale("")
|
java.class
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Locale("")
|
java.properties
|
If the previous step has found no resource bundle, proceed to Step 6. If a bundle has been found that is a base bundle (a bundle for 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.
The
control.getFallbackLocale
At this point, we have found a resource bundle that's not the base bundle. If this bundle set its parent during its instantiation, it is returned to the caller. Otherwise, its
parent chain
During the resource bundle loading process above, this factory method looks up the cache before calling the
control.newBundle
method. If the time-to-live period of the resource bundle found in the cache has expired, the factory method calls the
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
control.getTimeToLive
for details.
The following is an example of the bundle loading process with the default ResourceBundle.Control implementation.
Conditions:
Base bundle name: foo.bar.Messages
Requested Locale:
Locale.ITALY
Default Locale:
Locale.FRENCH
Available resource bundles: foo/bar/Messages_fr.properties and foo/bar/Messages.properties
First, getBundle tries loading a resource bundle in the following sequence.
class foo.bar.Messages_it_IT
file foo/bar/Messages_it_IT.properties
class foo.bar.Messages_it
file foo/bar/Messages_it.properties
class foo.bar.Messages
file foo/bar/Messages.properties
At this point, getBundle finds foo/bar/Messages.properties, which is put on hold because it's the base bundle. getBundle calls
control.getFallbackLocale("foo.bar.Messages", Locale.ITALY)
which returns Locale.FRENCH. Next, getBundle tries loading a bundle in the following sequence.
class foo.bar.Messages_fr
file foo/bar/Messages_fr.properties
class foo.bar.Messages
file foo/bar/Messages.properties
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.
Parameters:
baseName - the base name of the resource bundle, a fully qualified class name
targetLocale - the locale for which a resource bundle is desired
loader - the class loader from which to load the resource bundle
control - the control which gives information for the resource bundle loading process
Returns:
a resource bundle for the given base name and locale
Throws:
NullPointerException
- if baseName, targetLocale, loader, or control is null
MissingResourceException
- if no resource bundle for the specified base name can be found
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
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publicResourceBundle()
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public finalStringgetString(Stringkey)
(String)getObject(key).
clearCache
public finalString[]getStringArray(Stringkey)
Removes all resource bundles from the cache that have been loaded using the caller's class loader.
(String[])getObject(key).
Since:
1.6
See Also:
ResourceBundle.Control.getTimeToLive(String,Locale)
clearCache
publicObjectgetObject(Stringkey)
Removes all resource bundles from the cache that have been loaded using the given class loader.
loader - the class loader
Throws:
NullPointerException
- if loader is null
Since:
1.6
See Also:
ResourceBundle.Control.getTimeToLive(String,Locale)
handleGetObject
publicLocalegetLocale()
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.
Parameters:
key - the key for the desired object
the object for the given key, or null
Throws:
NullPointerException
- if key is null
getKeys
protected voidsetParent(ResourceBundleparent)
Returns an enumeration of the keys.
Returns:
an Enumeration of the keys contained in this ResourceBundle and its parent bundles.
containsKey
public static finalResourceBundlegetBundle(StringbaseName)
Determines whether the given key is contained in this ResourceBundle or its parent bundles.
getBundle(baseName, Locale.getDefault(), this.getClass().getClassLoader()),
key - the resource key
true if the given key is contained in this ResourceBundle or its parent bundles; false otherwise.
key
Since:
1.6
keySet
public static finalResourceBundlegetBundle(StringbaseName,Localelocale)
Returns a Set of all keys contained in this ResourceBundle and its parent bundles.
getBundle(baseName, locale, this.getClass().getClassLoader()),
a Set of all keys contained in this ResourceBundle and its parent bundles.
Since:
1.6
handleKeySet
public staticResourceBundlegetBundle(StringbaseName,Localelocale,ClassLoaderloader)
Returns a Set of the keys contained only in this ResourceBundle.
The default implementation returns a Set of the keys returned by the
getKeys
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
Locale.getDefault
method except for the ones for which the
handleGetObject
) 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):
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:
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
setParent
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 the next calls. Override this method in subclass implementations for faster handling.
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:
a Set of the keys contained only in this ResourceBundle
1.6
protected abstractObjecthandleGetObject(Stringkey)
public abstractEnumeration<String>getKeys()