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java.lang.Object
|
+----java.util.Locale
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
this class:
Locale(String language, String country)
Locale(String language, String country, String variant)
The first argument to both constructors is a valid ISO
Language Code. These codes are the lower-case two-letter
codes as defined by ISO-639.
You can find a full list of these codes at a number of sites, such as:
http://www.ics.uci.edu/pub/ietf/http/related/iso639.txt
The second argument to both constructors is a valid ISO Country
Code. These codes are the upper-case two-letter codes
as defined by ISO-3166.
You can find a full list of these codes at a number of sites, such as:
http://www.chemie.fu-berlin.de/diverse/doc/ISO_3166.html
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
ResourceBundle
.
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:
Locale.US
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:
NumberFormat.getInstance()
NumberFormat.getCurrencyInstance()
NumberFormat.getPercentInstance()
These methods have two variants; one with an explicit locale
and one without; the latter using the default locale.
NumberFormat.getInstance(myLocale)
NumberFormat.getCurrencyInstance(myLocale)
NumberFormat.getPercentInstance(myLocale)
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,
Locale displayLocale)
public static final String getDisplayName(Locale objectLocale)
// getDisplayName will throw MissingResourceException if the locale
// is not one of the available locales.
public static final Locale ENGLISH
public static final Locale FRENCH
public static final Locale GERMAN
public static final Locale ITALIAN
public static final Locale JAPANESE
public static final Locale KOREAN
public static final Locale CHINESE
public static final Locale SIMPLIFIED_CHINESE
public static final Locale TRADITIONAL_CHINESE
public static final Locale FRANCE
public static final Locale GERMANY
public static final Locale ITALY
public static final Locale JAPAN
public static final Locale KOREA
public static final Locale CHINA
public static final Locale PRC
public static final Locale TAIWAN
public static final Locale UK
public static final Locale US
public static final Locale CANADA
public static final Locale CANADA_FRENCH
public Locale(String language,
String country,
String variant)
public Locale(String language,
String country)
public static synchronized Locale getDefault()
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.
public static synchronized void setDefault(Locale newLocale)
setDefault
does not reset the host locale.
public String getLanguage()
public String getCountry()
public String getVariant()
public final String toString()
public String getISO3Language() throws MissingResourceException
public String getISO3Country() throws MissingResourceException
public final String getDisplayLanguage()
public String getDisplayLanguage(Locale inLocale)
public final String getDisplayCountry()
public String getDisplayCountry(Locale inLocale)
public final String getDisplayVariant()
public String getDisplayVariant(Locale inLocale)
public final String getDisplayName()
public String getDisplayName(Locale inLocale)
public Object clone()
public synchronized int hashCode()
public boolean equals(Object obj)
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