java.util
Class Locale

java.lang.Object
  java.util.Locale

All Implemented Interfaces:

Cloneable, Serializable

public final class Locale

extends Object

implements Cloneable, Serializable

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.

Create a Locale object using the constructors in this class:

 Locale(String language)
 Locale(String language, String country)
 Locale(String language, String country, String variant)
 

The language argument 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 country argument 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 variant argument is a vendor or browser-specific code. 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 construct a locale with parameters for language, country and variant as: "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 Java 2 platform 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.
 

Since:

1.1

Author:

Mark Davis

See Also:

ResourceBundle, Format, NumberFormat, Collator, Serialized Form

Field Summary

static Locale	CANADA Useful constant for country.
static Locale	CANADA_FRENCH Useful constant for country.
static Locale	CHINA Useful constant for country.
static Locale	CHINESE Useful constant for language.
private static String	compressedIsoCountries
private static String	compressedIsoLanguages
private String	country
private static Locale	defaultLocale
static Locale	ENGLISH Useful constant for language.
static Locale	FRANCE Useful constant for country.
static Locale	FRENCH Useful constant for language.
static Locale	GERMAN Useful constant for language.
static Locale	GERMANY Useful constant for country.
private int	hashcode Placeholder for the object's hash code.
private static String[]	isoCountries List of all 2-letter country codes currently defined in ISO 3166.
private static String[]	isoLanguages List of all 2-letter language codes currently defined in ISO 639.
static Locale	ITALIAN Useful constant for language.
static Locale	ITALY Useful constant for country.
static Locale	JAPAN Useful constant for country.
static Locale	JAPANESE Useful constant for language.
static Locale	KOREA Useful constant for country.
static Locale	KOREAN Useful constant for language.
private String	language
static Locale	PRC Useful constant for country.
(package private) static long	serialVersionUID serialization ID
static Locale	SIMPLIFIED_CHINESE Useful constant for language.
static Locale	TAIWAN Useful constant for country.
static Locale	TRADITIONAL_CHINESE Useful constant for language.
static Locale	UK Useful constant for country.
static Locale	US Useful constant for country.
private String	variant

Constructor Summary

Locale(String language)
Construct a locale from a language code.

Locale(String language, String country)
Construct a locale from language, country.

Locale(String language, String country, String variant)
Construct a locale from language, country, variant.

Method Summary

Object	clone() Overrides Cloneable
private static String[]	composeList(MessageFormat format, String[] list) Given a list of strings, return a list shortened to three elements.
private String	convertOldISOCodes(String language)
boolean	equals(Object obj) Returns true if this Locale is equal to another object.
private String	findStringMatch(String[][] languages, String desiredLanguage, String fallbackLanguage)
private static String	formatList(String[] patterns, String[] stringList) Format a list with an array of patterns.
static Locale[]	getAvailableLocales() Returns a list of all installed locales.
String	getCountry() Returns the country/region code for this locale, which will either be the empty string or an upercase ISO 3166 2-letter code.
static Locale	getDefault() Gets the current value of the default locale for this instance of the Java Virtual Machine.
String	getDisplayCountry() Returns a name for the locale's country that is appropriate for display to the user.
String	getDisplayCountry(Locale inLocale) Returns a name for the locale's country that is appropriate for display to the user.
String	getDisplayLanguage() Returns a name for the locale's language that is appropriate for display to the user.
String	getDisplayLanguage(Locale inLocale) Returns a name for the locale's language that is appropriate for display to the user.
String	getDisplayName() Returns a name for the locale that is appropriate for display to the user.
String	getDisplayName(Locale inLocale) Returns a name for the locale that is appropriate for display to the user.
String	getDisplayVariant() Returns a name for the locale's variant code that is appropriate for display to the user.
String	getDisplayVariant(Locale inLocale) Returns a name for the locale's variant code that is appropriate for display to the user.
private String[]	getDisplayVariantArray(ResourceBundle bundle) Return an array of the display names of the variant.
String	getISO3Country() Returns a three-letter abbreviation for this locale's country.
String	getISO3Language() Returns a three-letter abbreviation for this locale's language.
static String[]	getISOCountries() Returns a list of all 2-letter country codes defined in ISO 3166.
static String[]	getISOLanguages() Returns a list of all 2-letter language codes defined in ISO 639.
String	getLanguage() Returns the language code for this locale, which will either be the empty string or a lowercase ISO 639 code.
String	getVariant() Returns the variant code for this locale.
int	hashCode() Override hashCode.
private void	readObject(ObjectInputStream in)
static void	setDefault(Locale newLocale) Sets the default locale for this instance of the Java Virtual Machine.
private String	toLowerCase(String str)
String	toString() Getter for the programmatic name of the entire locale, with the language, country and variant separated by underbars.
private String	toUpperCase(String str)
private void	writeObject(ObjectOutputStream out)

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

ENGLISH

public static final Locale ENGLISH

Useful constant for language.

FRENCH

public static final Locale FRENCH

Useful constant for language.

GERMAN

public static final Locale GERMAN

Useful constant for language.

ITALIAN

public static final Locale ITALIAN

Useful constant for language.

JAPANESE

public static final Locale JAPANESE

Useful constant for language.

KOREAN

public static final Locale KOREAN

Useful constant for language.

CHINESE

public static final Locale CHINESE

Useful constant for language.

SIMPLIFIED_CHINESE

public static final Locale SIMPLIFIED_CHINESE

Useful constant for language.

TRADITIONAL_CHINESE

public static final Locale TRADITIONAL_CHINESE

Useful constant for language.

FRANCE

public static final Locale FRANCE

Useful constant for country.

GERMANY

public static final Locale GERMANY

Useful constant for country.

ITALY

public static final Locale ITALY

Useful constant for country.

JAPAN

public static final Locale JAPAN

Useful constant for country.

KOREA

public static final Locale KOREA

Useful constant for country.

CHINA

public static final Locale CHINA

Useful constant for country.

PRC

public static final Locale PRC

Useful constant for country.

TAIWAN

public static final Locale TAIWAN

Useful constant for country.

UK

public static final Locale UK

Useful constant for country.

US

public static final Locale US

Useful constant for country.

CANADA

public static final Locale CANADA

Useful constant for country.

CANADA_FRENCH

public static final Locale CANADA_FRENCH

Useful constant for country.

serialVersionUID

static final long serialVersionUID

serialization ID

See Also:

Constant Field Values

language

private String language

See Also:

getLanguage()

country

private String country

See Also:

getCountry()

variant

private String variant

See Also:

getVariant()

hashcode

private int hashcode

Placeholder for the object's hash code. Always -1.

defaultLocale

private static Locale defaultLocale

isoLanguages

private static String[] isoLanguages

List of all 2-letter language codes currently defined in ISO 639. (Because the Java VM specification turns an array constant into executable code that generates the array element by element, we keep the array in compressed form in a single string and build the array from it at run time when requested.) [We're now also using this table to store a mapping from 2-letter ISO language codes to 3-letter ISO language codes. Each group of characters consists of a comma, a 2-letter code, and a 3-letter code. We look up a 3-letter code by searching for a comma followed by a 2-letter code and then getting the three letters following the 2-letter code.]

compressedIsoLanguages

private static final String compressedIsoLanguages

See Also:

Constant Field Values

isoCountries

private static String[] isoCountries

List of all 2-letter country codes currently defined in ISO 3166. (Because the Java VM specification turns an array constant into executable code that generates the array element by element, we keep the array in compressed form in a single string and build the array from it at run time when requested.) [We're now also using this table to store a mapping from 2-letter ISO country codes to 3-letter ISO country codes. Each group of characters consists of a comma, a 2-letter code, and a 3-letter code. We look up a 3-letter code by searching for a comma followed by a 2-letter code and then getting the three letters following the 2-letter code.]

compressedIsoCountries

private static final String compressedIsoCountries

See Also:

Constant Field Values

Constructor Detail

Locale

public Locale(String language,
              String country,
              String variant)

Construct a locale from language, country, variant. NOTE: ISO 639 is not a stable standard; some of the language codes it defines (specifically iw, ji, and in) have changed. This constructor accepts both the old codes (iw, ji, and in) and the new codes (he, yi, and id), but all other API on Locale will return only the OLD codes.

Parameters:

language - lowercase two-letter ISO-639 code.

country - uppercase two-letter ISO-3166 code.

variant - vendor and browser specific code. See class description.

Throws:

NullPointerException - thrown if any argument is null.

Locale

public Locale(String language,
              String country)

Construct a locale from language, country. NOTE: ISO 639 is not a stable standard; some of the language codes it defines (specifically iw, ji, and in) have changed. This constructor accepts both the old codes (iw, ji, and in) and the new codes (he, yi, and id), but all other API on Locale will return only the OLD codes.

Parameters:

language - lowercase two-letter ISO-639 code.

country - uppercase two-letter ISO-3166 code.

Throws:

NullPointerException - thrown if either argument is null.

Locale

public Locale(String language)

Construct a locale from a language code. NOTE: ISO 639 is not a stable standard; some of the language codes it defines (specifically iw, ji, and in) have changed. This constructor accepts both the old codes (iw, ji, and in) and the new codes (he, yi, and id), but all other API on Locale will return only the OLD codes.

Parameters:

language - lowercase two-letter ISO-639 code.

Throws:

NullPointerException - thrown if argument is null.

Since:

1.4

Method Detail

getDefault

public static Locale getDefault()

Gets the current value of the default locale for this instance of the Java Virtual Machine.

The Java Virtual Machine sets the default locale during startup based on the host environment. It is used by many locale-sensitive methods if no locale is explicitly specified. It can be changed using the setDefault method.

Returns:

the default locale for this instance of the Java Virtual Machine

setDefault

public static void setDefault(Locale newLocale)

Sets the default locale for this instance of the Java Virtual Machine. This does not affect the host locale.

If there is a security manager, its checkPermission method is called with a PropertyPermission("user.language", "write") permission before the default locale is changed.

The Java Virtual Machine sets the default locale during startup based on the host environment. It is used by many locale-sensitive methods if no locale is explicitly specified.

Since changing the default locale may affect many different areas of functionality, this method should only be used if the caller is prepared to reinitialize locale-sensitive code running within the same Java Virtual Machine, such as the user interface.

Parameters:

newLocale - the new default locale

Throws:

SecurityException - if a security manager exists and its checkPermission method doesn't allow the operation.

NullPointerException - if newLocale is null

See Also:

SecurityManager.checkPermission(java.security.Permission), PropertyPermission

getAvailableLocales

public static Locale[] getAvailableLocales()

Returns a list of all installed locales.

getISOCountries

public static String[] getISOCountries()

Returns a list of all 2-letter country codes defined in ISO 3166. Can be used to create Locales.

getISOLanguages

public static String[] getISOLanguages()

Returns a list of all 2-letter language codes defined in ISO 639. Can be used to create Locales. [NOTE: ISO 639 is not a stable standard-- some languages' codes have changed. The list this function returns includes both the new and the old codes for the languages whose codes have changed.]

getLanguage

public String getLanguage()

Returns the language code for this locale, which will either be the empty string or a lowercase ISO 639 code.

NOTE: ISO 639 is not a stable standard-- some languages' codes have changed. Locale's constructor recognizes both the new and the old codes for the languages whose codes have changed, but this function always returns the old code. If you want to check for a specific language whose code has changed, don't do

 if (locale.getLanguage().equals("he")
    ...
 

Instead, do

 if (locale.getLanguage().equals(new Locale("he", "", "").getLanguage())
    ...

See Also:

getDisplayLanguage()

getCountry

public String getCountry()

Returns the country/region code for this locale, which will either be the empty string or an upercase ISO 3166 2-letter code.

See Also:

getDisplayCountry()

getVariant

public String getVariant()

Returns the variant code for this locale.

See Also:

getDisplayVariant()

toString

public final String toString()

Getter for the programmatic name of the entire locale, with the language, country and variant separated by underbars. Language is always lower case, and country is always upper case. If the language is missing, the string will begin with an underbar. If both the language and country fields are missing, this function will return the empty string, even if the variant field is filled in (you can't have a locale with just a variant-- the variant must accompany a valid language or country code). Examples: "en", "de_DE", "_GB", "en_US_WIN", "de__POSIX", "fr__MAC"

Overrides:

toString in class Object

Returns:

a string representation of the object.

See Also:

getDisplayName()

getISO3Language

public String getISO3Language()
                       throws MissingResourceException

Returns a three-letter abbreviation for this locale's language. If the locale doesn't specify a language, this will be the empty string. Otherwise, this will be a lowercase ISO 639-2/T language code. The ISO 639-2 language codes can be found on-line at ftp://dkuug.dk/i18n/iso-639-2.txt

Throws:

MissingResourceException - Throws MissingResourceException if the three-letter language abbreviation is not available for this locale.

getISO3Country

public String getISO3Country()
                      throws MissingResourceException

Returns a three-letter abbreviation for this locale's country. If the locale doesn't specify a country, this will be tbe the empty string. Otherwise, this will be an uppercase ISO 3166 3-letter country code.

Throws:

MissingResourceException - Throws MissingResourceException if the three-letter country abbreviation is not available for this locale.

getDisplayLanguage

public final String getDisplayLanguage()

Returns a name for the locale's language that is appropriate for display to the user. If possible, the name returned will be localized for the default locale. For example, if the locale is fr_FR and the default locale is en_US, getDisplayLanguage() will return "French"; if the locale is en_US and the default locale is fr_FR, getDisplayLanguage() will return "anglais". If the name returned cannot be localized for the default locale, (say, we don't have a Japanese name for Croatian), this function falls back on the English name, and uses the ISO code as a last-resort value. If the locale doesn't specify a language, this function returns the empty string.

getDisplayLanguage

public String getDisplayLanguage(Locale inLocale)

Returns a name for the locale's language that is appropriate for display to the user. If possible, the name returned will be localized according to inLocale. For example, if the locale is fr_FR and inLocale is en_US, getDisplayLanguage() will return "French"; if the locale is en_US and inLocale is fr_FR, getDisplayLanguage() will return "anglais". If the name returned cannot be localized according to inLocale, (say, we don't have a Japanese name for Croatian), this function falls back on the default locale, on the English name, and finally on the ISO code as a last-resort value. If the locale doesn't specify a language, this function returns the empty string.

getDisplayCountry

public final String getDisplayCountry()

Returns a name for the locale's country that is appropriate for display to the user. If possible, the name returned will be localized for the default locale. For example, if the locale is fr_FR and the default locale is en_US, getDisplayCountry() will return "France"; if the locale is en_US and the default locale is fr_FR, getDisplayLanguage() will return "Etats-Unis". If the name returned cannot be localized for the default locale, (say, we don't have a Japanese name for Croatia), this function falls back on the English name, and uses the ISO code as a last-resort value. If the locale doesn't specify a country, this function returns the empty string.

getDisplayCountry

public String getDisplayCountry(Locale inLocale)

Returns a name for the locale's country that is appropriate for display to the user. If possible, the name returned will be localized according to inLocale. For example, if the locale is fr_FR and inLocale is en_US, getDisplayCountry() will return "France"; if the locale is en_US and inLocale is fr_FR, getDisplayLanguage() will return "Etats-Unis". If the name returned cannot be localized according to inLocale. (say, we don't have a Japanese name for Croatia), this function falls back on the default locale, on the English name, and finally on the ISO code as a last-resort value. If the locale doesn't specify a country, this function returns the empty string.

getDisplayVariant

public final String getDisplayVariant()

Returns a name for the locale's variant code that is appropriate for display to the user. If possible, the name will be localized for the default locale. If the locale doesn't specify a variant code, this function returns the empty string.

getDisplayVariant

public String getDisplayVariant(Locale inLocale)

Returns a name for the locale's variant code that is appropriate for display to the user. If possible, the name will be localized for inLocale. If the locale doesn't specify a variant code, this function returns the empty string.

getDisplayName

public final String getDisplayName()

Returns a name for the locale that is appropriate for display to the user. This will be the values returned by getDisplayLanguage(), getDisplayCountry(), and getDisplayVariant() assembled into a single string. The display name will have one of the following forms:

language (country, variant)

language (country)

language (variant)

country (variant)

language

country

variant

depending on which fields are specified in the locale. If the language, country, and variant fields are all empty, this function returns the empty string.

getDisplayName

public String getDisplayName(Locale inLocale)

Returns a name for the locale that is appropriate for display to the user. This will be the values returned by getDisplayLanguage(), getDisplayCountry(), and getDisplayVariant() assembled into a single string. The display name will have one of the following forms:

language (country, variant)

language (country)

language (variant)

country (variant)

language

country

variant

depending on which fields are specified in the locale. If the language, country, and variant fields are all empty, this function returns the empty string.

clone

public Object clone()

Overrides Cloneable

Overrides:

clone in class Object

Returns:

a clone of this instance.

See Also:

Cloneable

hashCode

public int hashCode()

Override hashCode. Since Locales are often used in hashtables, caches the value for speed.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object.

See Also:

Object.equals(java.lang.Object), Hashtable

equals

public boolean equals(Object obj)

Returns true if this Locale is equal to another object. A Locale is deemed equal to another Locale with identical language, country, and variant, and unequal to all other objects.

Overrides:

equals in class Object

Parameters:

obj - the reference object with which to compare.

Returns:

true if this Locale is equal to the specified object.

See Also:

Object.hashCode(), Hashtable

getDisplayVariantArray

private String[] getDisplayVariantArray(ResourceBundle bundle)

Return an array of the display names of the variant.

Parameters:

bundle - the ResourceBundle to use to get the display names

Returns:

an array of display names, possible of zero length.

formatList

private static String formatList(String[] patterns,
                                 String[] stringList)

Format a list with an array of patterns.

Parameters:

patterns - an array of three patterns. The first pattern is not used. The second pattern should create a MessageFormat taking 0-3 arguments and formatting them into a list. The third pattern should take 2 arguments and is used by composeList. If patterns is null, then a the list is formatted by concatenation with the delimiter ','.

stringList - the list of strings to be formatted.

Returns:

a string representing the list.

composeList

private static String[] composeList(MessageFormat format,
                                    String[] list)

Given a list of strings, return a list shortened to three elements. Shorten it by applying the given format to the first two elements recursively.

Parameters:

format - a format which takes two arguments

list - a list of strings

Returns:

if the list is three elements or shorter, the same list; otherwise, a new list of three elements.

writeObject

private void writeObject(ObjectOutputStream out)
                  throws IOException

Throws:

IOException

readObject

private void readObject(ObjectInputStream in)
                 throws IOException,
                        ClassNotFoundException

Throws:

IOException

ClassNotFoundException

toLowerCase

private String toLowerCase(String str)

toUpperCase

private String toUpperCase(String str)

findStringMatch

private String findStringMatch(String[][] languages,
                               String desiredLanguage,
                               String fallbackLanguage)

convertOldISOCodes

private String convertOldISOCodes(String language)