A Locale object represents a specific geographical, political,
or cultural region. An operation that requires a Locale to perform
its task is called locale-sensitive and uses the Locale
to tailor information for the user. For example, displaying a number
is a locale-sensitive operation--the number should be formatted
according to the customs/conventions of the user's native country,
region, or culture.
You create a Locale object using one of the two constructors in
The second constructor requires a third argument--the Variant.
The Variant codes are vendor and browser-specific.
For example, use WIN for Windows, MAC for Macintosh, and POSIX for POSIX.
Where there are two variants, separate them with an underscore, and
put the most important one first. For
example, a Traditional Spanish collation might be referenced, with
"ES", "ES", "Traditional_WIN".
Because a Locale object is just an identifier for a region,
no validity check is performed when you construct a Locale.
If you want to see whether particular resources are available for the
Locale you construct, you must query those resources. For
example, ask the NumberFormat for the locales it supports
using its getAvailableLocales method.
Note: When you ask for a resource for a particular
locale, you get back the best available match, not necessarily
precisely what you asked for. For more information, look at
The Locale class provides a number of convenient constants
that you can use to create Locale objects for commonly used
locales. For example, the following creates a Locale object
for the United States:
Once you've created a Locale you can query it for information about
itself. Use getCountry to get the ISO Country Code and
getLanguage to get the ISO Language Code. You can
use getDisplayCountry to get the
name of the country suitable for displaying to the user. Similarly,
you can use getDisplayLanguage to get the name of
the language suitable for displaying to the user. Interestingly,
the getDisplayXXX methods are themselves locale-sensitive
and have two versions: one that uses the default locale and one
that uses the locale specified as an argument.
The JDK provides a number of classes that perform locale-sensitive
operations. For example, the NumberFormat class formats
numbers, currency, or percentages in a locale-sensitive manner. Classes
such as NumberFormat have a number of convenience methods
for creating a default object of that type. For example, the
NumberFormat class provides these three convenience methods
for creating a default NumberFormat object:
A Locale is the mechanism for identifying the kind of object
(NumberFormat) that you would like to get. The locale is
just a mechanism for identifying objects,
not a container for the objects themselves.
Each class that performs locale-sensitive operations allows you
to get all the available objects of that type. You can sift
through these objects by language, country, or variant,
and use the display names to present a menu to the user.
For example, you can create a menu of all the collation objects
suitable for a given language. Such classes must implement these
three class methods:
public static Locale getAvailableLocales()
public static String getDisplayName(Locale objectLocale,
public static final String getDisplayName(Locale objectLocale)
// getDisplayName will throw MissingResourceException if the locale
// is not one of the available locales.
Common method of getting the current default Locale.
Used for the presentation: menus, dialogs, etc.
Generally set once when your applet or application is initialized,
then never reset. (If you do reset the default locale, you
probably want to reload your GUI, so that the change is reflected
in your interface.)
More advanced programs will allow users to use different locales
for different fields, e.g. in a spreadsheet.
Note that the initial setting will match the host system.
Getter for the programmatic name of the entire locale,
with the language, country and variant separated by underbars.
If a field is missing, at most one underbar will occur.
Example: "EN", "DE_DE", "EN_US_WIN", "DE_POSIX", "FR_MAC"