Class Locale
- All Implemented Interfaces:
Serializable, Cloneable
public final class Locale extends Object implements Cloneable, Serializable
Locale represents a specific geographical, political, or cultural region. An API that requires a Locale to perform its task is locale-sensitive and uses the Locale to tailor information for the user. These locale-sensitive APIs are principally in the java.text and java.util packages. 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. Each Locale is associated with locale data which is provided by the Java runtime environment or any deployed LocaleServiceProvider implementations. The locale data provided by the Java runtime environment may vary by release.
Locale Composition
A Locale is composed of the bolded fields described below; note that a Locale need not have all such fields. For example, Locale.ENGLISH is only comprised of the language field. In contrast, a Locale such as the one returned by
Locale.forLanguageTag("en-Latn-US-POSIX-u-nu-latn") would be comprised of all the fields below. This particular Locale would represent English in the United States using the Latin script and numerics for use in POSIX environments.
Locale implements IETF BCP 47 and any deviations should be observed by the comments prefixed by "BCP 47 deviation:". RFC 5646 combines subtags from various ISO (639, 3166, 15924) standards which are also included in the composition of Locale. Additionally, the full list of valid codes for each field can be found in the IANA Language Subtag Registry (e.g. search for "Type: region").
- language
- ISO 639 alpha-2/alpha-3 language code or a registered language subtag 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.
- Case convention:
languageis case insensitive, butLocalealways canonicalizes to lower case. - Syntax: Well-formed
languagevalues have the form[a-zA-Z]{2,8}. - BCP 47 deviation: this is not the full BCP 47 language production, since it excludes extlang (as modern three-letter language codes are preferred).
- Example: "en" (English), "ja" (Japanese), "kok" (Konkani)
- script
- ISO 15924 alpha-4 script code.
- Case convention:
scriptis case insensitive, butLocalealways canonicalizes to title case (the first letter is upper case and the rest of the letters are lower case). - Syntax: Well-formed
scriptvalues 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.
- Case convention:
country (region)is case insensitive, butLocalealways canonicalizes to upper case. - Syntax: 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. When multiple variants exist, they should be separated by('_'|'-'). Variants of higher importance should precede the others. - BCP 47 deviation: 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. However, the variant field in
Localehas 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. - Case convention:
variantis case sensitive. BCP 47 deviation: BCP 47 treats the variant field as case insensitive. - Syntax: Well-formed
variantvalues have the formSUBTAG (('_'|'-') SUBTAG)*whereSUBTAG = [0-9][0-9a-zA-Z]{3} | [0-9a-zA-Z]{5,8}. - BCP 47 deviation: BCP 47 only uses hyphen ('-') as a delimiter,
Localeis more lenient. - Example: "polyton" (Polytonic Greek), "POSIX"
- extensions
- A map from single character keys to string values, indicating extensions apart from language identification.
- BCP 47 deviation: The
extensionsinLocaleimplement the semantics and syntax of BCP 47 extension subtags and private use subtags. Theextensionsfield cannot have empty values. - Case convention:
extensionsare case insensitive, butLocalecanonicalizes all extension keys and values to lower case. - Syntax: Well-formed keys are single characters from the set
[0-9a-zA-Z]. Well-formed values have the formSUBTAG ('-' SUBTAG)*where for the key 'x'SUBTAG = [0-9a-zA-Z]{1,8}and for other keysSUBTAG = [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"
Locale class does not validate this requirement. For example, the variant code "foobar" is well-formed since it is composed of 5 to 8 alphanumerics, but is not defined the IANA Language Subtag Registry. The Locale.Builder only checks if an individual field satisfies the syntactic requirement (is well-formed), but does not validate the value itself. Conversely, Locale::of and its overloads do not make any syntactic checks on the input. Unicode BCP 47 U 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".
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 provides access to the 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.
Default Locale
The default Locale is provided for any locale-sensitive methods if no Locale is explicitly specified as an argument, such as NumberFormat.getInstance(). The default Locale is determined at startup of the Java runtime and established in the following three phases:
- The locale-related system properties listed below are established from the host environment. Some system properties (except for
user.language) may not have values from the host environment.Locale-related System Properties Key Description user.languagelanguagefor the default Locale, such as "en" (English)user.scriptscriptfor the default Locale, such as "Latn" (Latin)user.countrycountryfor the default Locale, such as "US" (United States)user.variantvariantfor the default Locale, such as "POSIX"user.extensionsextensionsfor the default Locale, such as "u-ca-japanese" (Japanese Calendar) - The values of these system properties can be overridden by values designated at startup time. If the overriding value of the
user.extensionsproperty is unparsable, it is ignored. The overriding values of other properties are not checked for syntax or validity and are used directly in the default Locale. (Typically, system property values can be provided using the-Dcommand-line option of a launcher. For example, specifying-Duser.extensions=foobarbazresults in a default Locale with no extensions, while specifying-Duser.language=foobarbazresults in a default Locale whose language is "foobarbaz".) - The default
Localeinstance is constructed from the values of these system properties.
Altering the system property values with System.setProperties(Properties)/ System.setProperty(String, String) has no effect on the default Locale.
Once the default Locale is established, applications can query the default Locale with getDefault() and change it with setDefault(Locale). If the default Locale is changed with setDefault(Locale), the corresponding system properties are not altered. It is not recommended that applications read these system properties and parse or interpret them as their values may be out of date.
Locale Category
There are finer-grained default Locales specific for each Locale.Category. These category specific default Locales can be queried by getDefault(Category), and set by setDefault(Category, Locale). Construction of these category specific default Locales are determined by the corresponding system properties, which consist of the base system properties as listed above, suffixed by either ".display" or ".format" depending on the category. For example, the value of the user.language.display system property will be used in the language part of the default Locale for the Locale.Category.DISPLAY category. In the absence of category specific system properties, the "category-less" system properties are used, such as user.language in the previous example.
Obtaining a Locale
There are several ways to obtain a Locale object. It is advised against using the deprecated Locale constructors.
- Locale Constants
- A number of convenient constants are provided that return
Localeobjects for commonly used locales. For example,Locale.USis theLocaleobject for the United States. - Factory Methods
-
Locale::ofand its overloads obtain aLocaleobject from the givenlanguage,country, and/orvariant.forLanguageTag(String)obtains aLocaleobject for a well-formed BCP 47 language tag. - Builder
-
Locale.Builderis used to construct aLocaleobject that conforms to BCP 47 syntax. Use a builder to enforce syntactic restrictions on the input.
The following invocations produce Locale objects that are all equivalent:
Locale.US;
Locale.of("en", "US");
Locale.forLanguageTag("en-US");
new Locale.Builder().setLanguage("en").setRegion("US").build();
Usage Examples
Once a Locale is obtained, it can be queried for information about itself. For example, use getCountry() to get the country (or region) code and getLanguage() to get the language. getDisplayCountry() can be used to get the name of the country suitable for displaying to the user. Similarly, use getDisplayLanguage() to get the name of the language suitable for displaying to the user. The getDisplayXXX methods are themselves locale-sensitive and have two variants; one with an explicit locale parameter, and one without. The latter uses the default DISPLAY locale, so the following are equivalent :
Locale.getDefault().getDisplayCountry();
Locale.getDefault().getDisplayCountry(Locale.getDefault(Locale.Category.DISPLAY));
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 factory methods for creating a default object of that type. These methods generally have two variants; one with an explicit locale parameter, and one without. The latter uses the default FORMAT locale, so the following are equivalent :
NumberFormat.getCurrencyInstance();
NumberFormat.getCurrencyInstance(Locale.getDefault(Locale.Category.FORMAT));
The following example demonstrates locale-sensitive currency and date related operations under different locales :
var number = 1000;
NumberFormat.getCurrencyInstance(Locale.US).format(number); // returns "$1,000.00"
NumberFormat.getCurrencyInstance(Locale.JAPAN).format(number); // returns "Â¥1,000""
var date = LocalDate.of(2024, 1, 1);
DateTimeFormatter.ofLocalizedDate(FormatStyle.LONG).localizedBy(Locale.US).format(date); // returns "January 1, 2024"
DateTimeFormatter.ofLocalizedDate(FormatStyle.LONG).localizedBy(Locale.JAPAN).format(date); // returns "2024å¹´1æ1æ¥"
Locale Matching
If an application 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 the term "language tag" is used interchangeably with "locale" in the following locale matching documentation.
In order to match 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 select 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 the fewest number of subtags) that is an acceptable match. All 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.
If there is a language tag which matches completely to a language range above, the language tag is returned.1. zh-Hant-TW 2. zh-Hant 3. zh 4. en-US 5. en
"*" 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.
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.
- Implementation Note:
-
Compatibility
The following commentary is provided for apps that want to ensure interoperability with older releases of
Localeprovided by the reference implementation.Locale Behavior
In order to maintain compatibility, Locale's (deprecated) constructors,of(String, String, String), and its overloads retain their behavior prior to the Java Runtime Environment version 1.7. That is, a length constraint is not imposed on any of the input parameters. Similarly, the same preservation of past behavior is largely true for thetoString()method. Apps that previously parsed the output oftoString()into language, country, and variant fields can continue to do so (although this is strongly discouraged). A caveat is that 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 apps migrate away from constructing non-conforming locales and use the
forLanguageTag(String)andLocale.BuilderAPIs instead. Apps desiring a string representation of the complete locale can then always rely ontoLanguageTag()for this purpose.Special cases
For compatibility reasons, two non-conforming locales are treated as special cases. These are
ja_JP_JPandth_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_JPto 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 keyca(for "calendar") and typejapanese. 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_THto 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 keynu(for "number") and valuethai. When the Locale constructor is called with the arguments "th", "TH", "TH", the extension "u-nu-thai" is automatically added.Legacy language codes
Locale's constructors have always converted three language codes to their earlier, obsoleted forms:
hemaps toiw,yimaps toji, andidmaps toin. Since Java SE 17, this is no longer the case. Each language maps to its new form;iwmaps tohe,jimaps toyi, andinmaps toid.For backwards compatible behavior, the system property
java.locale.useOldISOCodesreverts the behavior back to that of before Java SE 17. If the system property is set totrue, those three current language codes are mapped to their backward compatible forms. The property is only read at Java runtime startup and subsequent calls toSystem.setProperty()will have no effect. As of Java SE 25, the use of thejava.locale.useOldISOCodessystem property is deprecated. This backwards compatible behavior will be removed in a future release of the JDK.The APIs added in Java SE 7 map between the old and new language codes, maintaining the mapped codes internal to Locale (so that
getLanguageandtoStringreflect the mapped code, which depends on thejava.locale.useOldISOCodessystem property), but using the new codes in the BCP 47 language tag APIs (so thattoLanguageTagreflects 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, seeResourceBundle.Control. - Since:
- 1.1
- External Specifications
- See Also:
Nested Class Summary
| Modifier and Type | Class | Description |
|---|---|---|
static final class |
Locale.Builder |
Builder is used to build instances of Locale from values configured by the setters. |
static enum |
Locale.Category |
Enum for locale categories. |
static enum |
Locale.FilteringMode |
This enum provides constants to select a filtering mode for locale matching. |
static enum |
Locale.IsoCountryCode |
Enum for specifying the type defined in ISO 3166. |
static final class |
Locale.LanguageRange |
This class expresses a Language Range defined in RFC 4647 Matching of Language Tags. |
Field Summary
| Modifier and Type | Field | Description |
|---|---|---|
static final Locale |
CANADA |
Useful constant for country. |
static final Locale |
CANADA_FRENCH |
Useful constant for country. |
static final Locale |
CHINA |
Useful constant for country. |
static final Locale |
CHINESE |
Useful constant for language. |
static final Locale |
ENGLISH |
Useful constant for language. |
static final Locale |
FRANCE |
Useful constant for country. |
static final Locale |
FRENCH |
Useful constant for language. |
static final Locale |
GERMAN |
Useful constant for language. |
static final Locale |
GERMANY |
Useful constant for country. |
static final Locale |
ITALIAN |
Useful constant for language. |
static final Locale |
ITALY |
Useful constant for country. |
static final Locale |
JAPAN |
Useful constant for country. |
static final Locale |
JAPANESE |
Useful constant for language. |
static final Locale |
KOREA |
Useful constant for country. |
static final Locale |
KOREAN |
Useful constant for language. |
static final Locale |
PRC |
Useful constant for country. |
static final char |
PRIVATE_USE_EXTENSION |
The key for the private use extension ('x'). |
static final Locale |
ROOT |
Useful constant for the root locale. |
static final Locale |
SIMPLIFIED_CHINESE |
Useful constant for language. |
static final Locale |
TAIWAN |
Useful constant for country. |
static final Locale |
TRADITIONAL_CHINESE |
Useful constant for language. |
static final Locale |
UK |
Useful constant for country. |
static final char |
UNICODE_LOCALE_EXTENSION |
The key for Unicode locale extension ('u'). |
static final Locale |
US |
Useful constant for country. |
Constructor Summary
| Constructor | Description |
|---|---|
Locale |
Deprecated. Locale constructors have been deprecated. |
Locale |
Deprecated. Locale constructors have been deprecated. |
Locale |
Deprecated. Locale constructors have been deprecated. |
Method Summary
| Modifier and Type | Method | Description |
|---|---|---|
static Stream |
availableLocales() |
Returns a stream of available locales. |
static String |
caseFoldLanguageTag |
Returns a case folded IETF BCP 47 language tag. |
Object |
clone() |
Overrides Cloneable. |
boolean |
equals |
Returns true if this Locale is equal to another object. |
static List |
filter |
Returns a list of matching Locale instances using the filtering mechanism defined in RFC 4647. |
static List |
filter |
Returns a list of matching Locale instances using the filtering mechanism defined in RFC 4647. |
static List |
filterTags |
Returns a list of matching languages tags using the basic filtering mechanism defined in RFC 4647. |
static List |
filterTags |
Returns a list of matching languages tags using the basic filtering mechanism defined in RFC 4647. |
static Locale |
forLanguageTag |
Returns a locale for the specified IETF BCP 47 language tag string. |
static Locale[] |
getAvailableLocales() |
Returns an array of available 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() |
Gets the current value of the default locale for this instance of the Java Virtual Machine. |
static Locale |
getDefault |
Gets the current value of the default locale for the specified Category for this instance of the Java Virtual Machine. |
final String |
getDisplayCountry() |
Returns a name for the locale's country that is appropriate for display to the user. |
String |
getDisplayCountry |
Returns a name for the locale's country that is appropriate for display to the user. |
final String |
getDisplayLanguage() |
Returns a name for the locale's language 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. |
final String |
getDisplayName() |
Returns a name for the locale 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 |
getDisplayScript() |
Returns a name for the locale's script that is appropriate for display to the user. |
String |
getDisplayScript |
Returns a name for the locale's script that is appropriate for display to the user. |
final String |
getDisplayVariant() |
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 |
Returns the extension (or private use) value associated with the specified key, or null if there is no extension associated with the key. |
Set |
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 of 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 Set |
getISOCountries |
Returns an unmodifiable Set of ISO3166 country codes for the specified type. |
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 |
getUnicodeLocaleAttributes() |
Returns the set of unicode locale attributes associated with this locale, or the empty set if it has no attributes. |
Set |
getUnicodeLocaleKeys() |
Returns the set of Unicode locale keys defined by this locale, or the empty set if this locale has none. |
String |
getUnicodeLocaleType |
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() |
|
int |
hashCode() |
Override hashCode. |
static Locale |
lookup |
Returns a Locale instance for the best-matching language tag using the lookup mechanism defined in RFC 4647. |
static String |
lookupTag |
Returns the best-matching language tag using the lookup mechanism defined in RFC 4647. |
static Locale |
of |
Obtains a locale from a language code. |
static Locale |
of |
Obtains a locale from language and country. |
static Locale |
of |
Obtains a locale from language, country and variant. |
static void |
setDefault |
Sets the default locale for this instance of the Java Virtual Machine. |
static void |
setDefault |
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. |
final 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. |
Field Details
ENGLISH
public static final Locale ENGLISH
FRENCH
public static final Locale FRENCH
GERMAN
public static final Locale GERMAN
ITALIAN
public static final Locale ITALIAN
JAPANESE
public static final Locale JAPANESE
KOREAN
public static final Locale KOREAN
CHINESE
public static final Locale CHINESE
SIMPLIFIED_CHINESE
public static final Locale SIMPLIFIED_CHINESE
TRADITIONAL_CHINESE
public static final Locale TRADITIONAL_CHINESE
FRANCE
public static final Locale FRANCE
GERMANY
public static final Locale GERMANY
ITALY
public static final Locale ITALY
JAPAN
public static final Locale JAPAN
KOREA
public static final Locale KOREA
UK
public static final Locale UK
US
public static final Locale US
CANADA
public static final Locale CANADA
CANADA_FRENCH
public static final Locale CANADA_FRENCH
ROOT
public static final Locale ROOT
- Since:
- 1.6
CHINA
public static final Locale CHINA
PRC
public static final Locale PRC
TAIWAN
public static final Locale TAIWAN
PRIVATE_USE_EXTENSION
public static final char PRIVATE_USE_EXTENSION
- Since:
- 1.7
- See Also:
UNICODE_LOCALE_EXTENSION
public static final char UNICODE_LOCALE_EXTENSION
- Since:
- 1.7
- See Also:
Constructor Details
Locale
@Deprecated(since="19") public Locale(String language, String country, String variant)
- Implementation Note:
- Obsolete ISO 639 codes ("iw", "ji", and "in") are mapped to their current forms. See Legacy language codes for more information.
- 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 theLocaleclass description about valid language values. -
country- An ISO 3166 alpha-2 country code or a UN M.49 numeric-3 area code. See theLocaleclass description about valid country values. -
variant- Any arbitrary value used to indicate a variation of aLocale. See theLocaleclass description for the details. - Throws:
-
NullPointerException- thrown if any argument is null.
Locale
@Deprecated(since="19") public Locale(String language, String country)
- Implementation Note:
- Obsolete ISO 639 codes ("iw", "ji", and "in") are mapped to their current forms. See Legacy language codes for more information.
- 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 theLocaleclass description about valid language values. -
country- An ISO 3166 alpha-2 country code or a UN M.49 numeric-3 area code. See theLocaleclass description about valid country values. - Throws:
-
NullPointerException- thrown if either argument is null.
Locale
@Deprecated(since="19") public Locale(String language)
- Implementation Note:
- Obsolete ISO 639 codes ("iw", "ji", and "in") are mapped to their current forms. See Legacy language codes for more information.
- 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 theLocaleclass description about valid language values. - Throws:
-
NullPointerException- thrown if argument is null. - Since:
- 1.4
Method Details
of
public static Locale of(String language, String country, String variant)
- Implementation Note:
- This method does not make any syntactic checks on the input. Use
Locale.Builderfor full syntactic checks with BCP47. - The two cases ("ja", "JP", "JP") and ("th", "TH", "TH") are handled specially, see Special Cases for more information.
- Obsolete ISO 639 codes ("iw", "ji", and "in") are mapped to their current forms. See Legacy language codes for more information.
- This method does not make any syntactic checks on the input. Use
- Parameters:
-
language- A language code. See theLocaleclass description of language values. -
country- A country code. See theLocaleclass description of country values. -
variant- Any arbitrary value used to indicate a variation of aLocale. See theLocaleclass description of variant values. - Returns:
- A
Localeobject - Throws:
-
NullPointerException- thrown if any argument is null. - Since:
- 19
of
public static Locale of(String language, String country)
- Implementation Note:
- This method does not make any syntactic checks on the input. Use
Locale.Builderfor full syntactic checks with BCP47. - Obsolete ISO 639 codes ("iw", "ji", and "in") are mapped to their current forms. See Legacy language codes for more information.
- This method does not make any syntactic checks on the input. Use
- Parameters:
-
language- A language code. See theLocaleclass description of language values. -
country- A country code. See theLocaleclass description of country values. - Returns:
- A
Localeobject - Throws:
-
NullPointerException- thrown if either argument is null. - Since:
- 19
of
public static Locale of(String language)
- Implementation Note:
- This method does not make any syntactic checks on the input. Use
Locale.Builderfor full syntactic checks with BCP47. - Obsolete ISO 639 codes ("iw", "ji", and "in") are mapped to their current forms. See Legacy language codes for more information.
- This method does not make any syntactic checks on the input. Use
- Parameters:
-
language- A language code. See theLocaleclass description of language values. - Returns:
- A
Localeobject - Throws:
-
NullPointerException- thrown if argument is null. - Since:
- 19
getDefault
public static Locale getDefault()
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(Locale) method.
- Returns:
- the default locale for this instance of the Java Virtual Machine
getDefault
public static Locale getDefault(Locale.Category category)
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 - Since:
- 1.7
- See Also:
setDefault
public static void setDefault(Locale newLocale)
default locale for this instance of the Java Virtual Machine. This does not affect the host locale. 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.
By setting the default locale with this method, all of the default locales for each Category are also set to the specified default locale.
- Parameters:
-
newLocale- the new default locale - Throws:
-
NullPointerException- ifnewLocaleis null
setDefault
public static void setDefault(Locale.Category category, Locale newLocale)
default locale for the specified Category for this instance of the Java Virtual Machine. This does not affect the host locale. 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.
- Parameters:
-
category- the specified category to set the default locale -
newLocale- the new default locale - Throws:
-
NullPointerException- if category and/or newLocale is null - Since:
- 1.7
- See Also:
getAvailableLocales
public static Locale[] getAvailableLocales()
LocaleServiceProvider implementations. At a minimum, the returned array must contain a Locale instance equal to Locale.ROOT and a Locale instance equal to Locale.US.- Returns:
- an array of available locales
availableLocales
public static Stream<Locale> availableLocales()
LocaleServiceProvider implementations. At a minimum, the returned stream must contain a Locale instance equal to Locale.ROOT and a Locale instance equal to Locale.US.- Implementation Note:
- Unlike
getAvailableLocales(), this method does not create a defensive copy of the Locale array. - Returns:
- a stream of available locales
- Since:
- 21
getISOCountries
public static String[] getISOCountries()
getISOCountries(Locale.IsoCountryCode type) with type Locale.IsoCountryCode.PART1_ALPHA2. Note: The Locale class also supports other codes for country (region), such as 3-letter numeric UN M.49 area codes. Therefore, the list returned by this method does not contain ALL valid codes that can be used to obtain Locales.
Note that this method does not return obsolete 2-letter country codes. ISO3166-3 codes which designate country codes for those obsolete codes, can be retrieved from getISOCountries(Locale.IsoCountryCode type) with type Locale.IsoCountryCode.PART3.
- Returns:
- An array of ISO 3166 two-letter country codes.
getISOCountries
public static Set<String> getISOCountries(Locale.IsoCountryCode type)
Set of ISO3166 country codes for the specified type.- Parameters:
-
type-Locale.IsoCountryCodespecified ISO code type. - Returns:
- an unmodifiable
Setof ISO3166 country codes for the specified type - Throws:
-
NullPointerException- if type is null - Since:
- 9
- See Also:
getISOLanguages
public static String[] getISOLanguages()
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.
- The
Localeclass also supports language codes up to 8 characters in length. Therefore, the list returned by this method does not contain ALL valid codes that can be used to obtain Locales.
- Returns:
- An array of ISO 639 two-letter language codes.
getLanguage
public String getLanguage()
- Implementation Note:
- This method returns the new forms for the obsolete ISO 639 codes ("iw", "ji", and "in"). See Legacy language codes for more information.
- Returns:
- The language code, or the empty string if none is defined.
- See Also:
getScript
public String getScript()
- Returns:
- The script code, or the empty string if none is defined.
- Since:
- 1.7
- See Also:
getCountry
public String getCountry()
- Returns:
- The country/region code, or the empty string if none is defined.
- See Also:
getVariant
public String getVariant()
- Returns:
- The variant code, or the empty string if none is defined.
- See Also:
hasExtensions
public boolean hasExtensions()
- Returns:
-
trueif thisLocalehas any extensions - Since:
- 1.8
stripExtensions
public Locale stripExtensions()
Locale with no extensions. If this Locale has no extensions, this Locale is returned.- Returns:
- a copy of this
Localewith no extensions, orthisifthishas no extensions - Since:
- 1.8
getExtension
public String getExtension(char key)
[0-9A-Za-z]. Keys are case-insensitive, so for example 'z' and 'Z' represent the same extension.- Parameters:
-
key- the extension key - Returns:
- The extension, or null if this locale defines no extension for the specified key.
- Throws:
-
IllegalArgumentException- if key is not well-formed - Since:
- 1.7
- See Also:
getExtensionKeys
public Set<Character> getExtensionKeys()
- Returns:
- The set of extension keys, or the empty set if this locale has no extensions.
- Since:
- 1.7
getUnicodeLocaleAttributes
public Set<String> getUnicodeLocaleAttributes()
- Returns:
- The set of attributes.
- Since:
- 1.7
getUnicodeLocaleType
public String getUnicodeLocaleType(String key)
- Parameters:
-
key- the Unicode locale key - Returns:
- The Unicode locale type associated with the key, or null if the locale does not define the key.
- Throws:
-
IllegalArgumentException- if the key is not well-formed -
NullPointerException- ifkeyis null - Since:
- 1.7
getUnicodeLocaleKeys
public Set<String> getUnicodeLocaleKeys()
- Returns:
- The set of Unicode locale keys, or the empty set if this locale has no Unicode locale keywords.
- Since:
- 1.7
toString
public final String toString()
Locale object, consisting of language, country, variant, script, and extensions as below: language + "_" + country + "_" + (variant + "_#" | "#") + script + "_" + extensionsLanguage is always lower case, country is always upper case, script is always title case, and extensions are always lower case. Extensions and private use subtags will be in canonical order as explained in
toLanguageTag(). When the locale has neither script nor extensions, the result is the same as in Java 6 and prior.
If both the language and country fields are missing, this function will return the empty string, even if the variant, script, or extensions field is present (a locale with just a variant is not allowed, the variant must accompany a well-formed language or country code).
If script or extensions are present and variant is missing, no underscore is added before the "#".
This behavior is designed to support debugging and to be compatible with previous uses of toString that expected language, country, and variant fields only. To represent a Locale as a String for interchange purposes, use toLanguageTag().
Examples:
ende_DE_GBen_US_WINde__POSIXzh_CN_#Hanszh_TW_#Hant_x-javath_TH_TH_#u-nu-thai
toLanguageTag
public String toLanguageTag()
If this Locale has a language, country, or variant that does not satisfy the IETF BCP 47 language tag syntax requirements, this method handles these fields as described below:
Language: If language is empty, or not well-formed (for example "a" or "e2"), it will be emitted as "und" (Undetermined).
Country: If country is not well-formed (for example "12" or "USA"), it will be omitted.
Variant: If variant is well-formed, each sub-segment (delimited by '-' or '_') is emitted as a subtag. Otherwise:
- if all sub-segments match
[0-9a-zA-Z]{1,8}(for example "WIN" or "Oracle_JDK_Standard_Edition"), the first ill-formed sub-segment and all following will be appended to the private use subtag. The first appended subtag will be "lvariant", followed by the sub-segments in order, separated by hyphen. For example, "x-lvariant-WIN", "Oracle-x-lvariant-JDK-Standard-Edition". - if any sub-segment does not match
[0-9a-zA-Z]{1,8}, the variant will be truncated and the problematic sub-segment and all following sub-segments will be omitted. If the remainder is non-empty, it will be emitted as a private use subtag as above (even if the remainder turns out to be well-formed). For example, "Solaris_isjustthecoolestthing" is emitted as "x-lvariant-Solaris", not as "solaris".
Special Conversions: Java supports some old locale representations, including deprecated ISO language codes, for compatibility. This method performs the following conversions:
- Deprecated ISO language codes "iw", "ji", and "in" are converted to "he", "yi", and "id", respectively.
- A locale with language "no", country "NO", and variant "NY", representing Norwegian Nynorsk (Norway), is converted to a language tag "nn-NO".
Note: Although the language tag obtained by this method is well-formed (satisfies the syntax requirements defined by the IETF BCP 47 specification), it is not necessarily a valid BCP 47 language tag. For example,
Locale.forLanguageTag("xx-YY").toLanguageTag();
- Returns:
- a BCP47 language tag representing the locale
- Since:
- 1.7
- See Also:
caseFoldLanguageTag
public static String caseFoldLanguageTag(String languageTag)
This method formats a language tag into one with case convention that adheres to section 2.1.1. Formatting of Language Tags of RFC5646. This format is defined as: All subtags, including extension and private use subtags, use lowercase letters with two exceptions: two-letter and four-letter subtags that neither appear at the start of the tag nor occur after singletons. Such two-letter subtags are all uppercase (as in the tags "en-CA-x-ca" or "sgn-BE-FR") and four- letter subtags are titlecase (as in the tag "az-Latn-x-latn"). As legacy tags, (defined as "grandfathered" in RFC5646) are not always well-formed, this method will simply case fold a legacy tag to match the exact case convention for the particular tag specified in the respective Legacy tags table.
Special Exceptions
To maintain consistency with variant which is case-sensitive, this method will neither case fold variant subtags nor case fold private use subtags prefixed by lvariant.
For example,
String tag = "ja-kana-jp-x-lvariant-Oracle-JDK-Standard-Edition";
Locale.caseFoldLanguageTag(tag); // returns "ja-Kana-JP-x-lvariant-Oracle-JDK-Standard-Edition"
String tag2 = "ja-kana-jp-x-Oracle-JDK-Standard-Edition";
Locale.caseFoldLanguageTag(tag2); // returns "ja-Kana-JP-x-oracle-jdk-standard-edition"
Excluding case folding, this method makes no modifications to the tag itself. Case convention of language tags does not carry meaning, and is simply recommended as it corresponds with various ISO standards, including: ISO639-1, ISO15924, and ISO3166-1.
As the formatting of the case convention is dependent on the positioning of certain subtags, callers of this method should ensure that the language tag is well-formed, (conforming to section 2.1. Syntax of RFC5646).
- Parameters:
-
languageTag- the IETF BCP 47 language tag. - Returns:
- a case folded IETF BCP 47 language tag
- Throws:
-
IllformedLocaleException- iflanguageTagis not well-formed -
NullPointerException- iflanguageTagisnull - Since:
- 21
- External Specifications
forLanguageTag
public static Locale forLanguageTag(String languageTag)
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 "iw", "ji", and "in" are mapped to "he", "yi", and "id" respectively. (This is the same canonicalization that's done in Locale's constructors.) See Legacy language codes for more information.
- 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" - BCP 47 language tags permit up to three extlang subtags. However, the second and third extlang subtags are always ignored. As such, the first extlang subtag in
languageTagis used as the language, and the primary language subtag and other extlang subtags are ignored. Language tags that exceed three extlang subtags are considered ill-formed starting at the offending extlang subtag.Locale.forLanguageTag("ar-aao").getLanguage(); // returns "aao" Locale.forLanguageTag("en-abc-def-us").toString(); // returns "abc_US" Locale.forLanguageTag("zh-yue-gan-cmn-czh-CN").toString(); // returns "yue"; "czh" exceeds the extlang limit, and subsequent // subtags are considered ill-formed - 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"
Legacy tags with canonical replacements are as follows:
| legacy 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 |
Legacy tags with no modern replacement will be converted as follows:
| legacy 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 legacy 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- iflanguageTagisnull - Since:
- 1.7
- See Also:
getISO3Language
public String getISO3Language() throws MissingResourceException
- Returns:
- a three-letter abbreviation of this locale's language
- Throws:
-
MissingResourceException- Throws MissingResourceException if three-letter language abbreviation is not available for this locale.
getISO3Country
public String getISO3Country() throws MissingResourceException
The ISO 3166-1 codes can be found on-line.
- Returns:
- a three-letter abbreviation of this locale's country
- Throws:
-
MissingResourceException- Throws MissingResourceException if the three-letter country abbreviation is not available for this locale.
getDisplayLanguage
public final String getDisplayLanguage()
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, 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.
getDisplayLanguage
public String getDisplayLanguage(Locale inLocale)
- Parameters:
-
inLocale- The locale for which to retrieve the display language. - Returns:
- The name of the display language appropriate to the given locale.
- Throws:
-
NullPointerException- ifinLocaleisnull
getDisplayScript
public String getDisplayScript()
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
DISPLAYlocale - Since:
- 1.7
getDisplayScript
public String getDisplayScript(Locale inLocale)
- Parameters:
-
inLocale- The locale for which to retrieve the display script. - Returns:
- the display name of the script code for the current default
DISPLAYlocale - Throws:
-
NullPointerException- ifinLocaleisnull - Since:
- 1.7
getDisplayCountry
public final String getDisplayCountry()
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, 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.
getDisplayCountry
public String getDisplayCountry(Locale inLocale)
- Parameters:
-
inLocale- The locale for which to retrieve the display country. - Returns:
- The name of the country appropriate to the given locale.
- Throws:
-
NullPointerException- ifinLocaleisnull
getDisplayVariant
public final String getDisplayVariant()
DISPLAY locale. If the locale doesn't specify a variant code, this function returns the empty string.- Returns:
- The name of the display variant code appropriate to the locale.
getDisplayVariant
public String getDisplayVariant(Locale inLocale)
- Parameters:
-
inLocale- The locale for which to retrieve the display variant code. - Returns:
- The name of the display variant code appropriate to the given locale.
- Throws:
-
NullPointerException- ifinLocaleisnull
getDisplayName
public final String getDisplayName()
language (script, country, variant(, extension)*)depending on which fields are specified in the locale. The field separator in the above parentheses, denoted as a comma character, may be localized depending on the locale. If the language, script, country, and variant fields are all empty, this function returns the empty string.
language (country(, extension)*)
language (variant(, extension)*)
script (country(, extension)*)
country (extension)*
- Returns:
- The name of the locale appropriate to display.
getDisplayName
public String getDisplayName(Locale inLocale)
language (script, country, variant(, extension)*)depending on which fields are specified in the locale. The field separator in the above parentheses, denoted as a comma character, may be localized depending on the locale. If the language, script, country, and variant fields are all empty, this function returns the empty string.
language (country(, extension)*)
language (variant(, extension)*)
script (country(, extension)*)
country (extension)*
- Parameters:
-
inLocale- The locale for which to retrieve the display name. - Returns:
- The name of the locale appropriate to display.
- Throws:
-
NullPointerException- ifinLocaleisnull
clone
hashCode
equals
public boolean equals(Object obj)
filter
public static List<Locale> filter(List<Locale.LanguageRange> priorityList, Collection<Locale> locales, Locale.FilteringMode mode)
Locale instances using the filtering mechanism defined in RFC 4647. This filter operation on the given locales ensures that only unique matching locale(s) are returned.- Parameters:
-
priorityList- user's Language Priority List in which each language tag is sorted in descending order based on priority or weight -
locales-Localeinstances used for matching -
mode- filtering mode - Returns:
- a list of
Localeinstances 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- ifpriorityListorlocalesisnull -
IllegalArgumentException- if one or more extended language ranges are included in the given list whenLocale.FilteringMode.REJECT_EXTENDED_RANGESis specified - Since:
- 1.8
filter
public static List<Locale> filter(List<Locale.LanguageRange> priorityList, Collection<Locale> locales)
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. This filter operation on the given locales ensures that only unique matching locale(s) are returned.- Parameters:
-
priorityList- user's Language Priority List in which each language tag is sorted in descending order based on priority or weight -
locales-Localeinstances used for matching - Returns:
- a list of
Localeinstances 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- ifpriorityListorlocalesisnull - Since:
- 1.8
filterTags
public static List<String> filterTags(List<Locale.LanguageRange> priorityList, Collection<String> tags, Locale.FilteringMode mode)
tags ensures that only unique matching tag(s) are returned with preserved case. In case of duplicate matching tags with the case difference, the first matching tag with preserved case is returned. For example, "de-ch" is returned out of the duplicate matching tags "de-ch" and "de-CH", if "de-ch" is checked first for matching in the given tags. Note that if the given tags is an unordered Collection, the returned matching tag out of duplicate tags is subject to change, depending on the implementation of the Collection.- 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- ifpriorityListortagsisnull -
IllegalArgumentException- if one or more extended language ranges are included in the given list whenLocale.FilteringMode.REJECT_EXTENDED_RANGESis specified - Since:
- 1.8
filterTags
public static List<String> filterTags(List<Locale.LanguageRange> priorityList, Collection<String> tags)
filterTags(List, Collection, FilteringMode) when mode is Locale.FilteringMode.AUTOSELECT_FILTERING. This filter operation on the given tags ensures that only unique matching tag(s) are returned with preserved case. In case of duplicate matching tags with the case difference, the first matching tag with preserved case is returned. For example, "de-ch" is returned out of the duplicate matching tags "de-ch" and "de-CH", if "de-ch" is checked first for matching in the given tags. Note that if the given tags is an unordered Collection, the returned matching tag out of duplicate tags is subject to change, depending on the implementation of the Collection.- 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- ifpriorityListortagsisnull - Since:
- 1.8
lookup
public static Locale lookup(List<Locale.LanguageRange> priorityList, Collection<Locale> locales)
Locale instance for the best-matching language tag using the lookup 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-Localeinstances used for matching - Returns:
- the best matching
Localeinstance chosen based on priority or weight, ornullif nothing matches. - Throws:
-
NullPointerException- ifpriorityListorlocalesisnull - Since:
- 1.8
lookupTag
public static String lookupTag(List<Locale.LanguageRange> priorityList, Collection<String> tags)
tags ensures that the first matching tag with preserved case is returned.- 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 used for matching - Returns:
- the best matching language tag chosen based on priority or weight, or
nullif nothing matches. - Throws:
-
NullPointerException- ifpriorityListortagsisnull - Since:
- 1.8
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Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/util/Locale.html