Locale

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 and conventions of the user's native country, region, or culture.

The Locale class implements IETF BCP 47 which is composed of RFC 4647 "Matching of Language Tags" and RFC 5646 "Tags for Identifying Languages" with support for the LDML (UTS#35, "Unicode Locale Data Markup Language") BCP 47-compatible extensions for locale data exchange.

A Locale object logically consists of the fields described below.

language

ISO 639 alpha-2 or alpha-3 language code, or registered language subtags up to 8 alpha letters (for future enhancements). When a language has both an alpha-2 code and an alpha-3 code, the alpha-2 code must be used. You can find a full list of valid language codes in the IANA Language Subtag Registry (search for "Type: language"). The language field is case insensitive, but Locale always canonicalizes to lower case.

Well-formed language values have the form [a-zA-Z]{2,8}. Note that this is not the the full BCP47 language production, since it excludes extlang. They are not needed since modern three-letter language codes replace them.

Example: "en" (English), "ja" (Japanese), "kok" (Konkani)

script

ISO 15924 alpha-4 script code. You can find a full list of valid script codes in the IANA Language Subtag Registry (search for "Type: script"). The script field is case insensitive, but Locale always canonicalizes to title case (the first letter is upper case and the rest of the letters are lower case).

Well-formed script values have the form [a-zA-Z]{4}

Example: "Latn" (Latin), "Cyrl" (Cyrillic)

country (region)

ISO 3166 alpha-2 country code or UN M.49 numeric-3 area code. You can find a full list of valid country and region codes in the IANA Language Subtag Registry (search for "Type: region"). The country (region) field is case insensitive, but Locale always canonicalizes to upper case.

Well-formed country/region values have the form [a-zA-Z]{2} | [0-9]{3}

Example: "US" (United States), "FR" (France), "029" (Caribbean)

variant

Any arbitrary value used to indicate a variation of a Locale. Where there are two or more variant values each indicating its own semantics, these values should be ordered by importance, with most important first, separated by underscore('_'). The variant field is case sensitive.

Note: IETF BCP 47 places syntactic restrictions on variant subtags. Also BCP 47 subtags are strictly used to indicate additional variations that define a language or its dialects that are not covered by any combinations of language, script and region subtags. You can find a full list of valid variant codes in the IANA Language Subtag Registry (search for "Type: variant").

However, the variant field in Locale has historically been used for any kind of variation, not just language variations. For example, some supported variants available in Java SE Runtime Environments indicate alternative cultural behaviors such as calendar type or number script. In BCP 47 this kind of information, which does not identify the language, is supported by extension subtags or private use subtags.

Well-formed variant values have the form SUBTAG (('_'|'-') SUBTAG)* where SUBTAG = [0-9][0-9a-zA-Z]{3} | [0-9a-zA-Z]{5,8}. (Note: BCP 47 only uses hyphen ('-') as a delimiter, this is more lenient).

Example: "polyton" (Polytonic Greek), "POSIX"

extensions

A map from single character keys to string values, indicating extensions apart from language identification. The extensions in Locale implement the semantics and syntax of BCP 47 extension subtags and private use subtags. The extensions are case insensitive, but Locale canonicalizes all extension keys and values to lower case. Note that extensions cannot have empty values.

Well-formed keys are single characters from the set [0-9a-zA-Z]. Well-formed values have the form SUBTAG ('-' SUBTAG)* where for the key 'x' SUBTAG = [0-9a-zA-Z]{1,8} and for other keys SUBTAG = [0-9a-zA-Z]{2,8} (that is, 'x' allows single-character subtags).

Example: key="u"/value="ca-japanese" (Japanese Calendar), key="x"/value="java-1-7"

Note: Although BCP 47 requires field values to be registered in the IANA Language Subtag Registry, the Locale class does not provide any validation features. The Builder only checks if an individual field satisfies the syntactic requirement (is well-formed), but does not validate the value itself. See Locale.Builder for details.

Unicode locale/language extension

UTS#35, "Unicode Locale Data Markup Language" defines optional attributes and keywords to override or refine the default behavior associated with a locale. A keyword is represented by a pair of key and type. For example, "nu-thai" indicates that Thai local digits (value:"thai") should be used for formatting numbers (key:"nu").

The keywords are mapped to a BCP 47 extension value using the extension key 'u' (UNICODE_LOCALE_EXTENSION). The above example, "nu-thai", becomes the extension "u-nu-thai".code

Thus, when a Locale object contains Unicode locale attributes and keywords, getExtension(UNICODE_LOCALE_EXTENSION) will return a String representing this information, for example, "nu-thai". The Locale class also provides getUnicodeLocaleAttributes(), getUnicodeLocaleKeys(), and getUnicodeLocaleType(String) which allow you to access Unicode locale attributes and key/type pairs directly. When represented as a string, the Unicode Locale Extension lists attributes alphabetically, followed by key/type sequences with keys listed alphabetically (the order of subtags comprising a key's type is fixed when the type is defined)

A well-formed locale key has the form [0-9a-zA-Z]{2}. A well-formed locale type has the form "" | [0-9a-zA-Z]{3,8} ('-' [0-9a-zA-Z]{3,8})* (it can be empty, or a series of subtags 3-8 alphanums in length). A well-formed locale attribute has the form [0-9a-zA-Z]{3,8} (it is a single subtag with the same form as a locale type subtag).

The Unicode locale extension specifies optional behavior in locale-sensitive services. Although the LDML specification defines various keys and values, actual locale-sensitive service implementations in a Java Runtime Environment might not support any particular Unicode locale attributes or key/type pairs.

Creating a Locale

There are several different ways to create a Locale object.

Builder

Using Locale.Builder you can construct a Locale object that conforms to BCP 47 syntax.

Constructors

The Locale class provides three constructors:

     Locale(String)
     Locale(String, String)
     Locale(String, String, String)
 

These constructors allow you to create a Locale object with language, country and variant, but you cannot specify script or extensions.

Factory Methods

The method forLanguageTag(String) creates a Locale object for a well-formed BCP 47 language tag.

Locale Constants

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
 

Locale Matching

If an application or a system is internationalized and provides localized resources for multiple locales, it sometimes needs to find one or more locales (or language tags) which meet each user's specific preferences. Note that a term "language tag" is used interchangeably with "locale" in this locale matching documentation.

In order to do matching a user's preferred locales to a set of language tags, RFC 4647 Matching of Language Tags defines two mechanisms: filtering and lookup. Filtering is used to get all matching locales, whereas lookup is to choose the best matching locale. Matching is done case-insensitively. These matching mechanisms are described in the following sections.

A user's preference is called a Language Priority List and is expressed as a list of language ranges. There are syntactically two types of language ranges: basic and extended. See Locale.LanguageRange for details.

Filtering

The filtering operation returns all matching language tags. It is defined in RFC 4647 as follows: "In filtering, each language range represents the least specific language tag (that is, the language tag with fewest number of subtags) that is an acceptable match. All of the language tags in the matching set of tags will have an equal or greater number of subtags than the language range. Every non-wildcard subtag in the language range will appear in every one of the matching language tags."

There are two types of filtering: filtering for basic language ranges (called "basic filtering") and filtering for extended language ranges (called "extended filtering"). They may return different results by what kind of language ranges are included in the given Language Priority List. Locale.FilteringMode is a parameter to specify how filtering should be done.

Lookup

The lookup operation returns the best matching language tags. It is defined in RFC 4647 as follows: "By contrast with filtering, each language range represents the most specific tag that is an acceptable match. The first matching tag found, according to the user's priority, is considered the closest match and is the item returned."

For example, if a Language Priority List consists of two language ranges, "zh-Hant-TW" and "en-US", in prioritized order, lookup method progressively searches the language tags below in order to find the best matching language tag.

    1. zh-Hant-TW
    2. zh-Hant
    3. zh
    4. en-US
    5. en
 

If there is a language tag which matches completely to a language range above, the language tag is returned.

"*" is the special language range, and it is ignored in lookup.

If multiple language tags match as a result of the subtag '*' included in a language range, the first matching language tag returned by an Iterator over a Collection of language tags is treated as the best matching one.

Use of Locale

Once you've created a Locale you can query it for information about itself. Use getCountry to get the country (or region) code and getLanguage to get the 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 DISPLAY locale and one that uses the locale specified as an argument.

The Java Platform provides a number of classes that perform locale-sensitive operations. For example, the NumberFormat class formats numbers, currency, and percentages in a locale-sensitive manner. Classes such as NumberFormat have several 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()
 

Each of these methods has two variants; one with an explicit locale and one without; the latter uses the default FORMAT 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.

Compatibility

In order to maintain compatibility with existing usage, Locale's constructors retain their behavior prior to the Java Runtime Environment version 1.7. The same is largely true for the toString method. Thus Locale objects can continue to be used as they were. In particular, clients who parse the output of toString into language, country, and variant fields can continue to do so (although this is strongly discouraged), although the variant field will have additional information in it if script or extensions are present.

In addition, BCP 47 imposes syntax restrictions that are not imposed by Locale's constructors. This means that conversions between some Locales and BCP 47 language tags cannot be made without losing information. Thus toLanguageTag cannot represent the state of locales whose language, country, or variant do not conform to BCP 47.

Because of these issues, it is recommended that clients migrate away from constructing non-conforming locales and use the forLanguageTag and Locale.Builder APIs instead. Clients desiring a string representation of the complete locale can then always rely on toLanguageTag for this purpose.

Special cases

For compatibility reasons, two non-conforming locales are treated as special cases. These are ja_JP_JP and th_TH_TH. These are ill-formed in BCP 47 since the variants are too short. To ease migration to BCP 47, these are treated specially during construction. These two cases (and only these) cause a constructor to generate an extension, all other values behave exactly as they did prior to Java 7.

Java has used ja_JP_JP to represent Japanese as used in Japan together with the Japanese Imperial calendar. This is now representable using a Unicode locale extension, by specifying the Unicode locale key ca (for "calendar") and type japanese. When the Locale constructor is called with the arguments "ja", "JP", "JP", the extension "u-ca-japanese" is automatically added.

Java has used th_TH_TH to represent Thai as used in Thailand together with Thai digits. This is also now representable using a Unicode locale extension, by specifying the Unicode locale key nu (for "number") and value thai. When the Locale constructor is called with the arguments "th", "TH", "TH", the extension "u-nu-thai" is automatically added.

Serialization

During serialization, writeObject writes all fields to the output stream, including extensions.

During deserialization, readResolve adds extensions as described in Special Cases, only for the two cases th_TH_TH and ja_JP_JP.

Legacy language codes

Locale's constructor has always converted three language codes to their earlier, obsoleted forms: he maps to iw, yi maps to ji, and id maps to in. This continues to be the case, in order to not break backwards compatibility.

The APIs added in 1.7 map between the old and new language codes, maintaining the old codes internal to Locale (so that getLanguage and toString reflect the old code), but using the new codes in the BCP 47 language tag APIs (so that toLanguageTag reflects the new one). This preserves the equivalence between Locales no matter which code or API is used to construct them. Java's default resource bundle lookup mechanism also implements this mapping, so that resources can be named using either convention, see ResourceBundle.Control.

Three-letter language/country(region) codes

The Locale constructors have always specified that the language and the country param be two characters in length, although in practice they have accepted any length. The specification has now been relaxed to allow language codes of two to eight characters and country (region) codes of two to three characters, and in particular, three-letter language codes and three-digit region codes as specified in the IANA Language Subtag Registry. For compatibility, the implementation still does not impose a length constraint.

Locale data

Note that locale data comes solely from ICU. User-supplied locale service providers (using the java.text.spi or java.util.spi mechanisms) are not supported.

Here are the versions of ICU (and the corresponding CLDR and Unicode versions) used in various Android releases:

Android 1.5 (Cupcake)/Android 1.6 (Donut)/Android 2.0 (Eclair)	ICU 3.8	CLDR 1.5	Unicode 5.0
Android 2.2 (Froyo)	ICU 4.2	CLDR 1.7	Unicode 5.1
Android 2.3 (Gingerbread)/Android 3.0 (Honeycomb)	ICU 4.4	CLDR 1.8	Unicode 5.2
Android 4.0 (Ice Cream Sandwich)	ICU 4.6	CLDR 1.9	Unicode 6.0
Android 4.1 (Jelly Bean)	ICU 4.8	CLDR 2.0	Unicode 6.0
Android 4.3 (Jelly Bean MR2)	ICU 50	CLDR 22.1	Unicode 6.2
Android 4.4 (KitKat)	ICU 51	CLDR 23	Unicode 6.2
Android 5.0 (Lollipop)	ICU 53	CLDR 25	Unicode 6.3
Android 6.0 (Marshmallow)	ICU 55.1	CLDR 27.0.1	Unicode 7.0
Android 7.0 (Nougat)	ICU 56.1	CLDR 28	Unicode 8.0
Android 8.0 (Oreo)	ICU 58.2	CLDR 30.0.3	Unicode 9.0
Android 9.0 (Pie)	ICU 60.2	CLDR 32.0.1	Unicode 10.0
Android 10.0 (Q)	ICU 63.2	CLDR 34	Unicode 11.0

Be wary of the default locale

Note that there are many convenience methods that automatically use the default locale, but using them may lead to subtle bugs.

The default locale is appropriate for tasks that involve presenting data to the user. In this case, you want to use the user's date/time formats, number formats, rules for conversion to lowercase, and so on. In this case, it's safe to use the convenience methods.

The default locale is not appropriate for machine-readable output. The best choice there is usually Locale.US – this locale is guaranteed to be available on all devices, and the fact that it has no surprising special cases and is frequently used (especially for computer-computer communication) means that it tends to be the most efficient choice too.

A common mistake is to implicitly use the default locale when producing output meant to be machine-readable. This tends to work on the developer's test devices (especially because so many developers use en_US), but fails when run on a device whose user is in a more complex locale.

For example, if you're formatting integers some locales will use non-ASCII decimal digits. As another example, if you're formatting floating-point numbers some locales will use ',' as the decimal point and '.' for digit grouping. That's correct for human-readable output, but likely to cause problems if presented to another computer (Double.parseDouble(String) can't parse such a number, for example). You should also be wary of the String.toLowerCase() and String.toUpperCase() overloads that don't take a Locale: in Turkey, for example, the characters 'i' and 'I' won't be converted to 'I' and 'i'. This is the correct behavior for Turkish text (such as user input), but inappropriate for, say, HTTP headers.

See Also

• Locale.Builder
• ResourceBundle
• Format
• NumberFormat
• Collator

Nested Class Summary

class	Locale.Builder		Builder is used to build instances of Locale from values configured by the setters.
enum	Locale.Category		Enum for locale categories.
enum	Locale.FilteringMode		This enum provides constants to select a filtering mode for locale matching.
class	Locale.LanguageRange		This class expresses a Language Range defined in RFC 4647 Matching of Language Tags.

Constant Summary

char	PRIVATE_USE_EXTENSION	The key for the private use extension ('x').
char	UNICODE_LOCALE_EXTENSION	The key for Unicode locale extension ('u').

Field Summary

public static final Locale	CANADA	Useful constant for country.
public static final Locale	CANADA_FRENCH	Useful constant for country.
public static final Locale	CHINA	Useful constant for country.
public static final Locale	CHINESE	Useful constant for language.
public static final Locale	ENGLISH	Useful constant for language.
public static final Locale	FRANCE	Useful constant for country.
public static final Locale	FRENCH	Useful constant for language.
public static final Locale	GERMAN	Useful constant for language.
public static final Locale	GERMANY	Useful constant for country.
public static final Locale	ITALIAN	Useful constant for language.
public static final Locale	ITALY	Useful constant for country.
public static final Locale	JAPAN	Useful constant for country.
public static final Locale	JAPANESE	Useful constant for language.
public static final Locale	KOREA	Useful constant for country.
public static final Locale	KOREAN	Useful constant for language.
public static final Locale	PRC	Useful constant for country.
public static final Locale	ROOT	Useful constant for the root locale.
public static final Locale	SIMPLIFIED_CHINESE	Useful constant for language.
public static final Locale	TAIWAN	Useful constant for country.
public static final Locale	TRADITIONAL_CHINESE	Useful constant for language.
public static final Locale	UK	Useful constant for country.
public static final Locale	US	Useful constant for country.

Public Constructor Summary

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

Public Method Summary

Object	clone() Overrides Cloneable.
boolean	equals(Object obj) Returns true if this Locale is equal to another object.
static List<Locale>	filter(List<Locale.LanguageRange> priorityList, Collection<Locale> locales) Returns a list of matching Locale instances using the filtering mechanism defined in RFC 4647.
static List<Locale>	filter(List<Locale.LanguageRange> priorityList, Collection<Locale> locales, Locale.FilteringMode mode) Returns a list of matching Locale instances using the filtering mechanism defined in RFC 4647.
static List<String>	filterTags(List<Locale.LanguageRange> priorityList, Collection<String> tags, Locale.FilteringMode mode) Returns a list of matching languages tags using the basic filtering mechanism defined in RFC 4647.
static List<String>	filterTags(List<Locale.LanguageRange> priorityList, Collection<String> tags) Returns a list of matching languages tags using the basic filtering mechanism defined in RFC 4647.
static Locale	forLanguageTag(String languageTag) Returns a locale for the specified IETF BCP 47 language tag string.
static Locale[]	getAvailableLocales() Returns an array of all installed locales.
String	getCountry() Returns the country/region code for this locale, which should either be the empty string, an uppercase ISO 3166 2-letter code, or a UN M.49 3-digit code.
static Locale	getDefault(Locale.Category category) Gets the current value of the default locale for the specified Category for this instance of the Java Virtual Machine.
static Locale	getDefault() Gets the current value of the default locale for this instance of the Java Virtual Machine.
String	getDisplayCountry(Locale locale) Returns the name of this locale's country, localized to locale.
String	getDisplayCountry() Returns a name for the locale's country that is appropriate for display to the user.
String	getDisplayLanguage(Locale locale) Returns the name of this locale's language, localized to locale.
String	getDisplayLanguage() 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 locale) Returns this locale's language name, country name, and variant, localized to locale.
String	getDisplayScript() Returns a name for the the locale's script that is appropriate for display to the user.
String	getDisplayScript(Locale inLocale) Returns a name for the locale's script 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.
String	getDisplayVariant() Returns a name for the locale's variant code that is appropriate for display to the user.
String	getExtension(char key) Returns the extension (or private use) value associated with the specified key, or null if there is no extension associated with the key.
Set<Character>	getExtensionKeys() Returns the set of extension keys associated with this locale, or the empty set if it has no extensions.
String	getISO3Country() Returns a three-letter abbreviation for this locale's country.
String	getISO3Language() Returns a three-letter abbreviation of 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 of this Locale.
String	getScript() Returns the script for this locale, which should either be the empty string or an ISO 15924 4-letter script code.
Set<String>	getUnicodeLocaleAttributes() Returns the set of unicode locale attributes associated with this locale, or the empty set if it has no attributes.
Set<String>	getUnicodeLocaleKeys() Returns the set of Unicode locale keys defined by this locale, or the empty set if this locale has none.
String	getUnicodeLocaleType(String key) Returns the Unicode locale type associated with the specified Unicode locale key for this locale.
String	getVariant() Returns the variant code for this locale.
boolean	hasExtensions() Returns true if this Locale has any extensions.
int	hashCode() Override hashCode.
static Locale	lookup(List<Locale.LanguageRange> priorityList, Collection<Locale> locales) Returns a Locale instance for the best-matching language tag using the lookup mechanism defined in RFC 4647.
static String	lookupTag(List<Locale.LanguageRange> priorityList, Collection<String> tags) Returns the best-matching language tag using the lookup mechanism defined in RFC 4647.
synchronized static void	setDefault(Locale newLocale) Sets the default locale for this instance of the Java Virtual Machine.
synchronized static void	setDefault(Locale.Category category, Locale newLocale) Sets the default locale for the specified Category for this instance of the Java Virtual Machine.
Locale	stripExtensions() Returns a copy of this Locale with no extensions.
String	toLanguageTag() Returns a well-formed IETF BCP 47 language tag representing this locale.
String	toString() Returns a string representation of this Locale object, consisting of language, country, variant, script, and extensions as below: language + "_" + country + "_" + (variant + "_#" | "#") + script + "-" + extensions Language is always lower case, country is always upper case, script is always title case, and extensions are always lower case.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Constants

public static final char PRIVATE_USE_EXTENSION

The key for the private use extension ('x').

See Also

• getExtension(char)
• Locale.Builder.setExtension(char, String)

Constant Value: 120

public static final char UNICODE_LOCALE_EXTENSION

The key for Unicode locale extension ('u').

See Also

• getExtension(char)
• Locale.Builder.setExtension(char, String)

Constant Value: 117

Fields

public static final Locale CANADA

Useful constant for country.

public static final Locale CANADA_FRENCH

Useful constant for country.

public static final Locale CHINA

Useful constant for country.

public static final Locale CHINESE

Useful constant for language.

public static final Locale ENGLISH

Useful constant for language.

public static final Locale FRANCE

Useful constant for country.

public static final Locale FRENCH

Useful constant for language.

public static final Locale GERMAN

Useful constant for language.

public static final Locale GERMANY

Useful constant for country.

public static final Locale ITALIAN

Useful constant for language.

public static final Locale ITALY

Useful constant for country.

public static final Locale JAPAN

Useful constant for country.

public static final Locale JAPANESE

Useful constant for language.

public static final Locale KOREA

Useful constant for country.

public static final Locale KOREAN

Useful constant for language.

public static final Locale PRC

Useful constant for country.

public static final Locale ROOT

Useful constant for the root locale. The root locale is the locale whose language, country, and variant are empty ("") strings. This is regarded as the base locale of all locales, and is used as the language/country neutral locale for the locale sensitive operations.

public static final Locale SIMPLIFIED_CHINESE

Useful constant for language.

public static final Locale TAIWAN

Useful constant for country.

public static final Locale TRADITIONAL_CHINESE

Useful constant for language.

public static final Locale UK

Useful constant for country.

public static final Locale US

Useful constant for country.

Public Constructors

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

Construct a locale from language, country and variant. This constructor normalizes the language value to lowercase and the country value to uppercase.

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.
• For backward compatibility reasons, this constructor does not make any syntactic checks on the input.
• The two cases ("ja", "JP", "JP") and ("th", "TH", "TH") are handled specially, see Special Cases for more information.

Parameters

language	An ISO 639 alpha-2 or alpha-3 language code, or a language subtag up to 8 characters in length. See the Locale class description about valid language values.
country	An ISO 3166 alpha-2 country code or a UN M.49 numeric-3 area code. See the Locale class description about valid country values.
variant	Any arbitrary value used to indicate a variation of a Locale. See the Locale class description for the details.

Throws

NullPointerException	thrown if any argument is null.

public Locale (String language, String country)

Construct a locale from language and country. This constructor normalizes the language value to lowercase and the country value to uppercase.

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.
• For backward compatibility reasons, this constructor does not make any syntactic checks on the input.

Parameters

language	An ISO 639 alpha-2 or alpha-3 language code, or a language subtag up to 8 characters in length. See the Locale class description about valid language values.
country	An ISO 3166 alpha-2 country code or a UN M.49 numeric-3 area code. See the Locale class description about valid country values.

Throws

NullPointerException	thrown if either argument is null.

public Locale (String language)

Construct a locale from a language code. This constructor normalizes the language value to lowercase.

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.
• For backward compatibility reasons, this constructor does not make any syntactic checks on the input.

Parameters

language	An ISO 639 alpha-2 or alpha-3 language code, or a language subtag up to 8 characters in length. See the Locale class description about valid language values.

Throws

NullPointerException	thrown if argument is null.

Public Methods

public Object clone ()

Overrides Cloneable.

Returns

• a copy of this object.

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, script, country, variant and extensions, and unequal to all other objects.

Parameters

obj	the object to compare this instance with.

Returns

• true if this Locale is equal to the specified object.

public static List<Locale> filter (List<Locale.LanguageRange> priorityList, Collection<Locale> locales)

Returns a list of matching Locale instances using the filtering mechanism defined in RFC 4647. This is equivalent to filter(List, Collection, FilteringMode) when mode is Locale.FilteringMode.AUTOSELECT_FILTERING.

Parameters

priorityList	user's Language Priority List in which each language tag is sorted in descending order based on priority or weight
locales	Locale instances used for matching

Returns

• a list of Locale instances for matching language tags sorted in descending order based on priority or weight, or an empty list if nothing matches. The list is modifiable.

Throws

NullPointerException	if priorityList or locales is null

public static List<Locale> filter (List<Locale.LanguageRange> priorityList, Collection<Locale> locales, Locale.FilteringMode mode)

Returns a list of matching Locale instances using the filtering mechanism defined in RFC 4647.

Parameters

priorityList	user's Language Priority List in which each language tag is sorted in descending order based on priority or weight
locales	Locale instances used for matching
mode	filtering mode

Returns

• a list of Locale instances for matching language tags sorted in descending order based on priority or weight, or an empty list if nothing matches. The list is modifiable.

Throws

NullPointerException	if priorityList or locales is null
IllegalArgumentException	if one or more extended language ranges are included in the given list when Locale.FilteringMode.REJECT_EXTENDED_RANGES is specified

public static List<String> filterTags (List<Locale.LanguageRange> priorityList, Collection<String> tags, Locale.FilteringMode mode)

Returns a list of matching languages tags using the basic filtering mechanism defined in RFC 4647.

Parameters

priorityList	user's Language Priority List in which each language tag is sorted in descending order based on priority or weight
tags	language tags
mode	filtering mode

Returns

• a list of matching language tags sorted in descending order based on priority or weight, or an empty list if nothing matches. The list is modifiable.

Throws

NullPointerException	if priorityList or tags is null
IllegalArgumentException	if one or more extended language ranges are included in the given list when Locale.FilteringMode.REJECT_EXTENDED_RANGES is specified

public static List<String> filterTags (List<Locale.LanguageRange> priorityList, Collection<String> tags)

Returns a list of matching languages tags using the basic filtering mechanism defined in RFC 4647. This is equivalent to filterTags(List, Collection, FilteringMode) when mode is Locale.FilteringMode.AUTOSELECT_FILTERING.

Parameters

priorityList	user's Language Priority List in which each language tag is sorted in descending order based on priority or weight
tags	language tags

Returns

• a list of matching language tags sorted in descending order based on priority or weight, or an empty list if nothing matches. The list is modifiable.

Throws

NullPointerException	if priorityList or tags is null

public static Locale forLanguageTag (String languageTag)

Returns a locale for the specified IETF BCP 47 language tag string.

If the specified language tag contains any ill-formed subtags, the first such subtag and all following subtags are ignored. Compare to Locale.Builder.setLanguageTag(String) which throws an exception in this case.

The following conversions are performed:

• The language code "und" is mapped to language "".
• The language codes "he", "yi", and "id" are mapped to "iw", "ji", and "in" respectively. (This is the same canonicalization that's done in Locale's constructors.)
• The portion of a private use subtag prefixed by "lvariant", if any, is removed and appended to the variant field in the result locale (without case normalization). If it is then empty, the private use subtag is discarded:

       Locale loc;
       loc = Locale.forLanguageTag("en-US-x-lvariant-POSIX");
       loc.getVariant(); // returns "POSIX"
       loc.getExtension('x'); // returns null
  
       loc = Locale.forLanguageTag("de-POSIX-x-URP-lvariant-Abc-Def");
       loc.getVariant(); // returns "POSIX_Abc_Def"
       loc.getExtension('x'); // returns "urp"
   

• When the languageTag argument contains an extlang subtag, the first such subtag is used as the language, and the primary language subtag and other extlang subtags are ignored:

       Locale.forLanguageTag("ar-aao").getLanguage(); // returns "aao"
       Locale.forLanguageTag("en-abc-def-us").toString(); // returns "abc_US"
   

• Case is normalized except for variant tags, which are left unchanged. Language is normalized to lower case, script to title case, country to upper case, and extensions to lower case.
• If, after processing, the locale would exactly match either ja_JP_JP or th_TH_TH with no extensions, the appropriate extensions are added as though the constructor had been called:

      Locale.forLanguageTag("ja-JP-x-lvariant-JP").toLanguageTag();
      // returns "ja-JP-u-ca-japanese-x-lvariant-JP"
      Locale.forLanguageTag("th-TH-x-lvariant-TH").toLanguageTag();
      // returns "th-TH-u-nu-thai-x-lvariant-TH"
   

This implements the 'Language-Tag' production of BCP47, and so supports grandfathered (regular and irregular) as well as private use language tags. Stand alone private use tags are represented as empty language and extension 'x-whatever', and grandfathered tags are converted to their canonical replacements where they exist.

Grandfathered tags with canonical replacements are as follows:

grandfathered tag		modern replacement
art-lojban		jbo
i-ami		ami
i-bnn		bnn
i-hak		hak
i-klingon		tlh
i-lux		lb
i-navajo		nv
i-pwn		pwn
i-tao		tao
i-tay		tay
i-tsu		tsu
no-bok		nb
no-nyn		nn
sgn-BE-FR		sfb
sgn-BE-NL		vgt
sgn-CH-DE		sgg
zh-guoyu		cmn
zh-hakka		hak
zh-min-nan		nan
zh-xiang		hsn

Grandfathered tags with no modern replacement will be converted as follows:

grandfathered tag		converts to
cel-gaulish		xtg-x-cel-gaulish
en-GB-oed		en-GB-x-oed
i-default		en-x-i-default
i-enochian		und-x-i-enochian
i-mingo		see-x-i-mingo
zh-min		nan-x-zh-min

For a list of all grandfathered tags, see the IANA Language Subtag Registry (search for "Type: grandfathered").

Note: there is no guarantee that toLanguageTag and forLanguageTag will round-trip.

Parameters

languageTag	the language tag

Returns

• The locale that best represents the language tag.

Throws

NullPointerException	if languageTag is null

See Also

• toLanguageTag()
• Locale.Builder.setLanguageTag(String)

public static Locale[] getAvailableLocales ()

Returns an array of all installed locales.

Returns

• An array of installed locales.

public String getCountry ()

Returns the country/region code for this locale, which should either be the empty string, an uppercase ISO 3166 2-letter code, or a UN M.49 3-digit code.

Returns

• The country/region code, or the empty string if none is defined.

See Also

• getDisplayCountry()

public static Locale getDefault (Locale.Category category)

Gets the current value of the default locale for the specified Category 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(Locale.Category, Locale) method.

Parameters

category	- the specified category to get the default locale

Returns

• the default locale for the specified Category for this instance of the Java Virtual Machine

Throws

NullPointerException	- if category is null

See Also

• setDefault(Locale.Category, Locale)

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

public String getDisplayCountry (Locale locale)

Returns the name of this locale's country, localized to locale. Returns the empty string if this locale does not correspond to a specific country.

Parameters

locale

public 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 DISPLAY locale. For example, if the locale is fr_FR and the default DISPLAY locale is en_US, getDisplayCountry() will return "France"; if the locale is en_US and the default DISPLAY locale is fr_FR, getDisplayCountry() will return "Etats-Unis". If the name returned cannot be localized for the default DISPLAY 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.

Returns

• The name of the country appropriate to the locale.

public String getDisplayLanguage (Locale locale)

Returns the name of this locale's language, localized to locale. If the language name is unknown, the language code is returned.

Parameters

locale

public 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 DISPLAY locale. For example, if the locale is fr_FR and the default DISPLAY locale is en_US, getDisplayLanguage() will return "French"; if the locale is en_US and the default DISPLAY locale is fr_FR, getDisplayLanguage() will return "anglais". If the name returned cannot be localized for the default DISPLAY 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.

Returns

• The name of the display language.

public String getDisplayName ()

Returns a name for the locale that is appropriate for display to the user. This will be the values returned by getDisplayLanguage(), getDisplayScript(), getDisplayCountry(), and getDisplayVariant() assembled into a single string. The the non-empty values are used in order, with the second and subsequent names in parentheses. For example:

language (script, country, variant)
language (country)
language (variant)
script (country)
country

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

Returns

• The name of the locale appropriate to display.

public String getDisplayName (Locale locale)

Returns this locale's language name, country name, and variant, localized to locale. The exact output form depends on whether this locale corresponds to a specific language, script, country and variant.

For example:

• new Locale("en").getDisplayName(Locale.US) -> English
• new Locale("en", "US").getDisplayName(Locale.US) -> English (United States)
• new Locale("en", "US", "POSIX").getDisplayName(Locale.US) -> English (United States,Computer)
• Locale.forLanguageTag("zh-Hant-CN").getDisplayName(Locale.US) -> Chinese (Traditional Han,China)
• new Locale("en").getDisplayName(Locale.FRANCE) -> anglais
• new Locale("en", "US").getDisplayName(Locale.FRANCE) -> anglais (États-Unis)
• new Locale("en", "US", "POSIX").getDisplayName(Locale.FRANCE) -> anglais (États-Unis,informatique).

Parameters

locale

public String getDisplayScript ()

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

Returns

• the display name of the script code for the current default DISPLAY locale

public String getDisplayScript (Locale inLocale)

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

Parameters