The {@code 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 {@code Locale} is associated with locale data which is provided * by the Java runtime environment or any deployed {@link * java.util.spi.LocaleServiceProvider LocaleServiceProvider} implementations. * The locale data provided by the Java runtime environment may vary by release. * *
A {@code Locale} is composed of the bolded fields described below; note that a * {@code Locale} need not have all such fields. For example, {@link * Locale#ENGLISH Locale.ENGLISH} is only comprised of the language field. * In contrast, a {@code Locale} such as the one returned by {@code * Locale.forLanguageTag("en-Latn-US-POSIX-u-nu-latn")} would be comprised of all * the fields below. This particular {@code Locale} would represent English in * the United States using the Latin script and numerics for use in POSIX * environments. *
* {@code 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 {@code 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"). * *
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' ({@link #UNICODE_LOCALE_EXTENSION}). The above * example, "nu-thai", becomes the extension "u-nu-thai". * *
Thus, when a {@code Locale} object contains Unicode locale * attributes and keywords, * {@code getExtension(UNICODE_LOCALE_EXTENSION)} will return a * String representing this information, for example, "nu-thai". The * {@code Locale} class also provides {@link * #getUnicodeLocaleAttributes}, {@link #getUnicodeLocaleKeys}, and * {@link #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 * {@code [0-9a-zA-Z]{2}}. A well-formed locale type has the * form {@code "" | [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 * {@code [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. * *
The default Locale is provided for any locale-sensitive methods if no * {@code Locale} is explicitly specified as an argument, such as * {@link NumberFormat#getInstance()}. The default Locale is determined at startup * of the Java runtime and established in the following three phases: *
| Locale-related System Properties Key | *Description |
|---|---|
| {@systemProperty user.language} | *{@link ##def_language language} for the default Locale, * such as "en" (English) |
| {@systemProperty user.script} | *{@link ##def_script script} for the default Locale, * such as "Latn" (Latin) |
| {@systemProperty user.country} | *{@link ##def_region country} for the default Locale, * such as "US" (United States) |
| {@systemProperty user.variant} | *{@link ##def_variant variant} for the default Locale, * such as "POSIX" |
| {@systemProperty user.extensions} | *{@link ##def_extensions extensions} for the default Locale, * such as "u-ca-japanese" (Japanese Calendar) |
Altering the system property values with {@link System#setProperties(Properties)}/ * {@link System#setProperty(String, String)} has no effect on the default Locale. *
Once the default Locale is established, applications can query the default * Locale with {@link #getDefault()} and change it with {@link #setDefault(Locale)}. * If the default Locale is changed with {@link #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. * *
There are finer-grained default Locales specific for each {@link Locale.Category}. * These category specific default Locales can be queried by {@link #getDefault(Category)}, * and set by {@link #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 * {@code ".display"} or {@code ".format"} depending on the category. For example, * the value of the {@code user.language.display} system property will be used in the * {@code language} part of the default Locale for the {@link Locale.Category#DISPLAY} * category. In the absence of category specific system properties, the "category-less" * system properties are used, such as {@code user.language} in the previous example. * *
There are several ways to obtain a {@code Locale} object. * It is advised against using the deprecated {@code Locale} constructors. * *
The following invocations produce Locale objects that are all equivalent: * {@snippet lang=java : * Locale.US; * Locale.of("en", "US"); * Locale.forLanguageTag("en-US"); * new Locale.Builder().setLanguage("en").setRegion("US").build(); * } * *
Once a {@code Locale} is {@linkplain ##ObtainingLocale obtained}, * it can be queried for information about itself. For example, use {@link * #getCountry} to get the country (or region) code and {@link #getLanguage} to * get the language. {@link #getDisplayCountry} can be used to get the * name of the country suitable for displaying to the user. Similarly, * use {@link #getDisplayLanguage()} to get the name of * the language suitable for displaying to the user. The {@code getDisplayXXX} * methods are themselves locale-sensitive and have two variants; one with an explicit * locale parameter, and one without. The latter uses the default {@link * Locale.Category#DISPLAY DISPLAY} locale, so the following are equivalent : * {@snippet lang=java : * 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 {@code NumberFormat} class formats * numbers, currency, and percentages in a locale-sensitive manner. Classes such * as {@code 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 {@link * Locale.Category#FORMAT FORMAT} locale, so the following are equivalent : * {@snippet lang=java : * NumberFormat.getCurrencyInstance(); * NumberFormat.getCurrencyInstance(Locale.getDefault(Locale.Category.FORMAT)); * } * *
* The following example demonstrates locale-sensitive currency and * date related operations under different locales : * {@snippet lang = java: * var number = 1000; * NumberFormat.getCurrencyInstance(Locale.US).format(number); // returns "$1,000.00" * NumberFormat.getCurrencyInstance(Locale.JAPAN).format(number); // returns "\u00A51,000"" * 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 "2024\u5e741\u67081\u65e5" * } * *
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 "{@index "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 * {@link Locale.LanguageRange Locale.LanguageRange} for details. * * *
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. * {@link Locale.FilteringMode} is a parameter to specify how filtering should * be done. * *
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, * {@code "zh-Hant-TW"} and {@code "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 **
{@code "*"} is the special language range, and it is ignored in lookup. * *
If multiple language tags match as a result of the subtag {@code '*'} * included in a language range, the first matching language tag returned by * an {@link Iterator} over a {@link Collection} of language tags is treated as * the best matching one. * *
During serialization, writeObject writes all fields to the output * stream, including extensions. * *
During deserialization, readResolve adds extensions as described * in {@linkplain ##special_cases_constructor Special Cases}, only * for the two cases th_TH_TH and ja_JP_JP. * * @implNote *
The following commentary is provided for apps that want to ensure * interoperability with older releases of {@code Locale} provided by the * reference implementation. *
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 {@link #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 * {@link #forLanguageTag(String)} and {@link Locale.Builder} APIs instead. * Apps desiring a string representation of the complete locale can * then always rely on {@link #toLanguageTag} for this purpose. * *
For compatibility reasons, two * non-conforming locales are treated as special cases. These are * {@code ja_JP_JP} and {@code th_TH_TH}. These are ill-formed * in BCP 47 since the {@linkplain ##def_variant 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 {@code 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 {@code ca} (for "calendar") and type * {@code japanese}. When the Locale constructor is called with the * arguments "ja", "JP", "JP", the extension "u-ca-japanese" is * automatically added. * *
Java has used {@code 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 * {@code nu} (for "number") and value {@code thai}. When the Locale * constructor is called with the arguments "th", "TH", "TH", the * extension "u-nu-thai" is automatically added. * *
Locale's constructors have always converted three language codes to * their earlier, obsoleted forms: {@code he} maps to {@code iw}, * {@code yi} maps to {@code ji}, and {@code id} maps to * {@code in}. Since Java SE 17, this is no longer the case. Each * language maps to its new form; {@code iw} maps to {@code he}, {@code ji} * maps to {@code yi}, and {@code in} maps to {@code id}. * *
For backwards compatible behavior, the system property * {@systemProperty java.locale.useOldISOCodes} reverts the behavior * back to that of before Java SE 17. If the system property is set to * {@code true}, those three current language codes are mapped to their * backward compatible forms. The property is only read at Java runtime * startup and subsequent calls to {@code System.setProperty()} will * have no effect. * *
The APIs added in 1.7 map between the old and new language codes,
* maintaining the mapped codes internal to Locale (so that
* {@code getLanguage} and {@code toString} reflect the mapped
* code, which depends on the {@code java.locale.useOldISOCodes} system
* property), but using the new codes in the BCP 47 language tag APIs (so
* that {@code 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 {@link ResourceBundle.Control}.
*
* @spec https://www.rfc-editor.org/info/rfc4647
* RFC 4647: Matching of Language Tags
* @spec https://www.rfc-editor.org/info/rfc5646
* RFC 5646: Tags for Identifying Languages
* @spec https://unicode.org/reports/tr35/
* Unicode Locale Data Markup Language
* @see Builder
* @see ResourceBundle
* @see java.text.Format
* @see java.text.NumberFormat
* @see java.text.Collator
* @author Mark Davis
* @since 1.1
*/
public final class Locale implements Cloneable, Serializable {
/** Useful constant for language.
*/
public static final Locale ENGLISH;
/** Useful constant for language.
*/
public static final Locale FRENCH;
/** Useful constant for language.
*/
public static final Locale GERMAN;
/** Useful constant for language.
*/
public static final Locale ITALIAN;
/** Useful constant for language.
*/
public static final Locale JAPANESE;
/** Useful constant for language.
*/
public static final Locale KOREAN;
/** Useful constant for language.
*/
public static final Locale CHINESE;
/** Useful constant for language.
*/
public static final Locale SIMPLIFIED_CHINESE;
/** Useful constant for language.
*/
public static final Locale TRADITIONAL_CHINESE;
/** Useful constant for country.
*/
public static final Locale FRANCE;
/** Useful constant for country.
*/
public static final Locale GERMANY;
/** Useful constant for country.
*/
public static final Locale ITALY;
/** Useful constant for country.
*/
public static final Locale JAPAN;
/** Useful constant for country.
*/
public static final Locale KOREA;
/** Useful constant for country.
*/
public static final Locale UK;
/** Useful constant for country.
*/
public static final Locale US;
/** Useful constant for country.
*/
public static final Locale CANADA;
/** Useful constant for country.
*/
public static final Locale CANADA_FRENCH;
/**
* 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.
*
* @since 1.6
*/
public static final Locale ROOT;
private static final Map
* 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
* {@link #setDefault(Locale)} method.
*
* @return the default locale for this instance of the Java Virtual Machine
*/
public static Locale getDefault() {
// do not synchronize this method - see 4071298
return defaultLocale;
}
/**
* Gets the current value of the {@link ##default_locale 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
* {@link #setDefault(Locale.Category, Locale)} method.
*
* @param category the specified category to get the default locale
* @throws NullPointerException if category is null
* @return the default locale for the specified Category for this instance
* of the Java Virtual Machine
* @see #setDefault(Locale.Category, Locale)
* @since 1.7
*/
public static Locale getDefault(Locale.Category category) {
// do not synchronize this method - see 4071298
Objects.requireNonNull(category);
if (category == Category.DISPLAY) {
Locale loc = defaultDisplayLocale; // volatile read
if (loc == null) {
loc = getDisplayLocale();
}
return loc;
} else {
assert category == Category.FORMAT : "Unknown category";
Locale loc = defaultFormatLocale; // volatile read
if (loc == null) {
loc = getFormatLocale();
}
return loc;
}
}
private static synchronized Locale getDisplayLocale() {
Locale loc = defaultDisplayLocale;
if (loc == null) {
loc = defaultDisplayLocale = initDefault(Category.DISPLAY);
}
return loc;
}
private static synchronized Locale getFormatLocale() {
Locale loc = defaultFormatLocale;
if (loc == null) {
loc = defaultFormatLocale = initDefault(Category.FORMAT);
}
return loc;
}
private static Locale initDefault() {
return getInstance(
StaticProperty.USER_LANGUAGE,
StaticProperty.USER_SCRIPT,
StaticProperty.USER_COUNTRY,
StaticProperty.USER_VARIANT,
getDefaultExtensions(StaticProperty.USER_EXTENSIONS)
.orElse(null));
}
private static Locale initDefault(Locale.Category category) {
Locale locale = Locale.defaultLocale;
return getInstance(
category == Category.DISPLAY ? StaticProperty.USER_LANGUAGE_DISPLAY : StaticProperty.USER_LANGUAGE_FORMAT,
category == Category.DISPLAY ? StaticProperty.USER_SCRIPT_DISPLAY : StaticProperty.USER_SCRIPT_FORMAT,
category == Category.DISPLAY ? StaticProperty.USER_COUNTRY_DISPLAY : StaticProperty.USER_COUNTRY_FORMAT,
category == Category.DISPLAY ? StaticProperty.USER_VARIANT_DISPLAY : StaticProperty.USER_VARIANT_FORMAT,
getDefaultExtensions(category == Category.DISPLAY ? StaticProperty.USER_EXTENSIONS_DISPLAY : StaticProperty.USER_EXTENSIONS_FORMAT)
.orElse(locale.getLocaleExtensions()));
}
private static Optional
* 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.
*
* @throws NullPointerException if {@code newLocale} is null
* @param newLocale the new default locale
*/
public static synchronized void setDefault(Locale newLocale) {
setDefault(Category.DISPLAY, newLocale);
setDefault(Category.FORMAT, newLocale);
defaultLocale = newLocale;
}
/**
* Sets the {@link ##default_locale 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.
*
* @param category the specified category to set the default locale
* @param newLocale the new default locale
* @throws NullPointerException if category and/or newLocale is null
* @see #getDefault(Locale.Category)
* @since 1.7
*/
public static synchronized void setDefault(Locale.Category category,
Locale newLocale) {
if (category == null)
throw new NullPointerException("Category cannot be NULL");
if (newLocale == null)
throw new NullPointerException("Can't set default locale to NULL");
switch (category) {
case DISPLAY:
defaultDisplayLocale = newLocale;
break;
case FORMAT:
defaultFormatLocale = newLocale;
break;
default:
assert false: "Unknown Category";
}
}
/**
* {@return an array of available locales}
*
* The returned array represents the union of locales supported
* by the Java runtime environment and by deployed
* {@link java.util.spi.LocaleServiceProvider LocaleServiceProvider}
* implementations. At a minimum, the returned array must contain a
* {@code Locale} instance equal to {@link #ROOT Locale.ROOT} and
* a {@code Locale} instance equal to {@link #US Locale.US}.
*/
public static Locale[] getAvailableLocales() {
return LocaleServiceProviderPool.getAllAvailableLocales();
}
/**
* {@return a stream of available locales}
*
* The returned stream represents the union of locales supported
* by the Java runtime environment and by deployed
* {@link java.util.spi.LocaleServiceProvider LocaleServiceProvider}
* implementations. At a minimum, the returned stream must contain a
* {@code Locale} instance equal to {@link #ROOT Locale.ROOT} and
* a {@code Locale} instance equal to {@link #US Locale.US}.
*
* @implNote Unlike {@code getAvailableLocales()}, this method does
* not create a defensive copy of the Locale array.
* @since 21
*/
public static Stream
* Note: The {@code 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 {@link #getISOCountries(Locale.IsoCountryCode type)} with
* {@code type} {@link IsoCountryCode#PART3}.
* @return An array of ISO 3166 two-letter country codes.
*/
public static String[] getISOCountries() {
if (isoCountries == null) {
isoCountries = getISO2Table(LocaleISOData.isoCountryTable);
}
String[] result = new String[isoCountries.length];
System.arraycopy(isoCountries, 0, result, 0, isoCountries.length);
return result;
}
/**
* {@return a {@code Set} of ISO3166 country codes for the specified type}
*
* @param type {@link Locale.IsoCountryCode} specified ISO code type.
* @see java.util.Locale.IsoCountryCode
* @throws NullPointerException if type is null
* @since 9
*/
public static Set
* Note:
* 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 {@code toString} that expected language, country, and variant
* fields only. To represent a Locale as a String for interchange purposes, use
* {@link #toLanguageTag}.
*
* Examples: If this {@code 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
* {@linkplain ##def_language well-formed} (for example "a" or
* "e2"), it will be emitted as "und" (Undetermined).
*
* Country: If country is not {@linkplain ##def_region well-formed}
* (for example "12" or "USA"), it will be omitted.
*
* Variant: If variant is {@linkplain ##def_variant
* well-formed}, each sub-segment
* (delimited by '-' or '_') is emitted as a subtag. Otherwise:
* Special Conversions: Java supports some old locale
* representations, including deprecated ISO language codes,
* for compatibility. This method performs the following
* conversions:
* 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,
* {@snippet lang=java :
* Locale.forLanguageTag("xx-YY").toLanguageTag();
* }
*
* will return "xx-YY", but the language subtag "xx" and the
* region subtag "YY" are invalid because they are not registered
* in the IANA Language Subtag Registry.
*
* @return a BCP47 language tag representing the locale
* @see #forLanguageTag(String)
* @since 1.7
*/
public String toLanguageTag() {
String lTag = this.languageTag;
if (lTag != null) {
return lTag;
}
LanguageTag tag = LanguageTag.parseLocale(baseLocale, localeExtensions);
StringBuilder buf = new StringBuilder();
String subtag = tag.getLanguage();
if (!subtag.isEmpty()) {
buf.append(LanguageTag.canonicalizeLanguage(subtag));
}
subtag = tag.getScript();
if (!subtag.isEmpty()) {
buf.append(LanguageTag.SEP);
buf.append(LanguageTag.canonicalizeScript(subtag));
}
subtag = tag.getRegion();
if (!subtag.isEmpty()) {
buf.append(LanguageTag.SEP);
buf.append(LanguageTag.canonicalizeRegion(subtag));
}
List 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
* {@link ##legacy_tags Legacy tags} table.
*
* Special Exceptions
* To maintain consistency with {@link ##def_variant variant}
* which is case-sensitive, this method will neither case fold variant
* subtags nor case fold private use subtags prefixed by {@code lvariant}.
*
* For example,
* {@snippet lang=java :
* 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).
*
* @param languageTag the IETF BCP 47 language tag.
* @throws IllformedLocaleException if {@code languageTag} is not well-formed
* @throws NullPointerException if {@code languageTag} is {@code null}
* @spec https://www.rfc-editor.org/rfc/rfc5646.html#section-2.1
* RFC5646 2.1. Syntax
* @spec https://www.rfc-editor.org/rfc/rfc5646#section-2.1.1
* RFC5646 2.1.1. Formatting of Language Tags
* @since 21
*/
public static String caseFoldLanguageTag(String languageTag) {
return LanguageTag.caseFoldTag(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 {@link Locale.Builder#setLanguageTag(String)} which throws an exception
* in this case.
*
* The following conversions are performed: Legacy tags with canonical replacements are as follows:
*
* Legacy tags with no modern replacement will be
* converted as follows:
*
* For a list of all legacy tags, see the
* IANA Language Subtag Registry (search for "Type: grandfathered").
*
* Note: there is no guarantee that {@code toLanguageTag}
* and {@code forLanguageTag} will round-trip.
*
* @param languageTag the language tag
* @return The locale that best represents the language tag.
* @throws NullPointerException if {@code languageTag} is {@code null}
* @see #toLanguageTag()
* @see java.util.Locale.Builder#setLanguageTag(String)
* @since 1.7
*/
public static Locale forLanguageTag(String languageTag) {
LanguageTag tag = LanguageTag.parse(
languageTag, new ParsePosition(0), true);
InternalLocaleBuilder bldr = new InternalLocaleBuilder();
bldr.setLanguageTag(tag);
BaseLocale base = bldr.getBaseLocale();
LocaleExtensions exts = bldr.getLocaleExtensions();
if (exts == null && !base.getVariant().isEmpty()) {
exts = getCompatibilityExtensions(base.getLanguage(), base.getScript(),
base.getRegion(), base.getVariant());
}
return getInstance(base, exts);
}
/**
* {@return a three-letter abbreviation of this locale's language}
*
* If the language matches an ISO 639-1 two-letter code, the
* corresponding ISO 639-2/T three-letter lowercase code is
* returned. The ISO 639-2 language codes can be found on-line,
* see "Codes for the Representation of Names of Languages Part 2:
* Alpha-3 Code". If the locale specifies a three-letter
* language, the language is returned as is. If the locale does
* not specify a language the empty string is returned.
*
* @throws MissingResourceException Throws MissingResourceException if
* three-letter language abbreviation is not available for this locale.
*/
public String getISO3Language() throws MissingResourceException {
String lang = baseLocale.getLanguage();
if (lang.length() == 3) {
return lang;
}
String language3 = getISO3Code(lang, LocaleISOData.isoLanguageTable);
if (language3 == null) {
throw new MissingResourceException("Couldn't find 3-letter language code for "
+ lang, "FormatData_" + toString(), "ShortLanguage");
}
return language3;
}
/**
* {@return a three-letter abbreviation of this locale's country}
*
* If the country matches an ISO 3166-1 alpha-2 code, the
* corresponding ISO 3166-1 alpha-3 uppercase code is returned.
* If the locale doesn't specify a country, this will be the empty
* string.
*
* The ISO 3166-1 codes can be found on-line.
*
* @throws MissingResourceException Throws MissingResourceException if the
* three-letter country abbreviation is not available for this locale.
*/
public String getISO3Country() throws MissingResourceException {
String country3 = getISO3Code(baseLocale.getRegion(), LocaleISOData.isoCountryTable);
if (country3 == null) {
throw new MissingResourceException("Couldn't find 3-letter country code for "
+ baseLocale.getRegion(), "FormatData_" + toString(), "ShortCountry");
}
return country3;
}
private static String getISO3Code(String iso2Code, String table) {
int codeLength = iso2Code.length();
if (codeLength == 0) {
return "";
}
int tableLength = table.length();
int index = tableLength;
if (codeLength == 2) {
char c1 = iso2Code.charAt(0);
char c2 = iso2Code.charAt(1);
for (index = 0; index < tableLength; index += 5) {
if (table.charAt(index) == c1
&& table.charAt(index + 1) == c2) {
break;
}
}
}
return index < tableLength ? table.substring(index + 2, index + 5) : null;
}
/**
* 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
* {@link Locale.Category#DISPLAY DISPLAY} locale.
* For example, if the locale is fr_FR and the default
* {@link Locale.Category#DISPLAY DISPLAY} locale
* is en_US, getDisplayLanguage() will return "French"; if the locale is en_US and
* the default {@link Locale.Category#DISPLAY DISPLAY} locale is fr_FR,
* getDisplayLanguage() will return "anglais".
* If the name returned cannot be localized for the default
* {@link Locale.Category#DISPLAY 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.
*
* @return The name of the display language.
*/
public final String getDisplayLanguage() {
return getDisplayLanguage(getDefault(Category.DISPLAY));
}
/**
* Returns a name for the locale's language that is appropriate for display to the
* user.
* If possible, the name returned will be localized according to inLocale.
* For example, if the locale is fr_FR and inLocale
* is en_US, getDisplayLanguage() will return "French"; if the locale is en_US and
* inLocale is fr_FR, getDisplayLanguage() will return "anglais".
* If the name returned cannot be localized according to inLocale,
* this function falls back on the English name, and finally
* on the ISO code as a last-resort value. If the locale doesn't specify a language,
* this function returns the empty string.
*
* @param inLocale The locale for which to retrieve the display language.
* @return The name of the display language appropriate to the given locale.
* @throws NullPointerException if {@code inLocale} is {@code null}
*/
public String getDisplayLanguage(Locale inLocale) {
return getDisplayString(baseLocale.getLanguage(), null, inLocale, DISPLAY_LANGUAGE);
}
/**
* 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 default
* {@link Locale.Category#DISPLAY DISPLAY} locale. Returns
* the empty string if this locale doesn't specify a script code.
*
* @return the display name of the script code for the current default
* {@link Locale.Category#DISPLAY DISPLAY} locale
* @since 1.7
*/
public String getDisplayScript() {
return getDisplayScript(getDefault(Category.DISPLAY));
}
/**
* 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.
*
* @param inLocale The locale for which to retrieve the display script.
* @return the display name of the script code for the current default
* {@link Locale.Category#DISPLAY DISPLAY} locale
* @throws NullPointerException if {@code inLocale} is {@code null}
* @since 1.7
*/
public String getDisplayScript(Locale inLocale) {
return getDisplayString(baseLocale.getScript(), null, inLocale, DISPLAY_SCRIPT);
}
/**
* 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
* {@link Locale.Category#DISPLAY DISPLAY} locale.
* For example, if the locale is fr_FR and the default
* {@link Locale.Category#DISPLAY DISPLAY} locale
* is en_US, getDisplayCountry() will return "France"; if the locale is en_US and
* the default {@link Locale.Category#DISPLAY DISPLAY} locale is fr_FR,
* getDisplayCountry() will return "Etats-Unis".
* If the name returned cannot be localized for the default
* {@link Locale.Category#DISPLAY 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.
*
* @return The name of the country appropriate to the locale.
*/
public final String getDisplayCountry() {
return getDisplayCountry(getDefault(Category.DISPLAY));
}
/**
* Returns a name for the locale's country that is appropriate for display to the
* user.
* If possible, the name returned will be localized according to inLocale.
* For example, if the locale is fr_FR and inLocale
* is en_US, getDisplayCountry() will return "France"; if the locale is en_US and
* inLocale is fr_FR, getDisplayCountry() will return "Etats-Unis".
* If the name returned cannot be localized according to inLocale,
* this function falls back on the English name, and finally
* on the ISO code as a last-resort value. If the locale doesn't specify a country,
* this function returns the empty string.
*
* @param inLocale The locale for which to retrieve the display country.
* @return The name of the country appropriate to the given locale.
* @throws NullPointerException if {@code inLocale} is {@code null}
*/
public String getDisplayCountry(Locale inLocale) {
return getDisplayString(baseLocale.getRegion(), null, inLocale, DISPLAY_COUNTRY);
}
private String getDisplayString(String code, String cat, Locale inLocale, int type) {
Objects.requireNonNull(inLocale);
Objects.requireNonNull(code);
if (code.isEmpty()) {
return "";
}
LocaleServiceProviderPool pool =
LocaleServiceProviderPool.getPool(LocaleNameProvider.class);
String rbKey = (type == DISPLAY_VARIANT ? "%%"+code : code);
String result = pool.getLocalizedObject(
LocaleNameGetter.INSTANCE,
inLocale, rbKey, type, code, cat);
return result != null ? result : code;
}
/**
* Returns a name for the locale's variant code that is appropriate for display to the
* user. If possible, the name will be localized for the default
* {@link Locale.Category#DISPLAY DISPLAY} locale. If the locale
* doesn't specify a variant code, this function returns the empty string.
*
* @return The name of the display variant code appropriate to the locale.
*/
public final String getDisplayVariant() {
return getDisplayVariant(getDefault(Category.DISPLAY));
}
/**
* Returns a name for the locale's variant code that is appropriate for display to the
* user. If possible, the name will be localized for inLocale. If the locale
* doesn't specify a variant code, this function returns the empty string.
*
* @param inLocale The locale for which to retrieve the display variant code.
* @return The name of the display variant code appropriate to the given locale.
* @throws NullPointerException if {@code inLocale} is {@code null}
*/
public String getDisplayVariant(Locale inLocale) {
if (baseLocale.getVariant().isEmpty())
return "";
LocaleResources lr = LocaleProviderAdapter
.getResourceBundleBased()
.getLocaleResources(inLocale);
String names[] = getDisplayVariantArray(inLocale);
// Get the localized patterns for formatting a list, and use
// them to format the list.
return formatList(names,
lr.getLocaleName("ListCompositionPattern"));
}
/**
* Returns a name for the locale that is appropriate for display to the
* user. This will be the values returned by getDisplayLanguage(),
* getDisplayScript(), getDisplayCountry(), getDisplayVariant() and
* optional {@linkplain ##def_locale_extension Unicode extensions}
* assembled into a single string. The non-empty values are used in order, with
* the second and subsequent names in parentheses. For example:
* The following example shows how to obtain a {@code Locale} object
* using a {@code Builder}.
* {@snippet lang=java :
* Locale aLocale = new Locale.Builder().setLanguage("sr").setScript("Latn").setRegion("RS").build();
* }
*
* Builders can be reused; {@code clear()} resets all
* fields to their default values.
*
* @see Locale#forLanguageTag(String)
* @see Locale#of(String, String, String)
* @since 1.7
*/
public static final class Builder {
private final InternalLocaleBuilder localeBuilder;
/**
* Constructs an empty Builder. The default value of all
* fields, extensions, and private use information is the
* empty string.
*/
public Builder() {
localeBuilder = new InternalLocaleBuilder();
}
/**
* Resets the {@code Builder} to match the provided
* {@code locale}. Existing state is discarded.
*
* All fields of the locale must be well-formed, see {@link Locale}.
*
* Locales with any ill-formed fields cause
* {@code IllformedLocaleException} to be thrown, except for the
* following three cases which are accepted for compatibility
* reasons: The typical language value is a two or three-letter language
* code as defined in ISO639.
*
* @param language the language
* @return This builder.
* @throws IllformedLocaleException if {@code language} is ill-formed
*/
public Builder setLanguage(String language) {
try {
localeBuilder.setLanguage(language);
} catch (LocaleSyntaxException e) {
throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
}
return this;
}
/**
* Sets the script. If {@code script} is null or the empty string,
* the script in this {@code Builder} is removed.
* Otherwise, the script must be {@linkplain Locale##def_script well-formed} or an
* exception is thrown.
*
* The typical script value is a four-letter script code as defined by ISO 15924.
*
* @param script the script
* @return This builder.
* @throws IllformedLocaleException if {@code script} is ill-formed
*/
public Builder setScript(String script) {
try {
localeBuilder.setScript(script);
} catch (LocaleSyntaxException e) {
throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
}
return this;
}
/**
* Sets the region. If region is null or the empty string, the region
* in this {@code Builder} is removed. Otherwise,
* the region must be {@linkplain Locale##def_region well-formed} or an
* exception is thrown.
*
* The typical region value is a two-letter ISO 3166 code or a
* three-digit UN M.49 area code.
*
* The country value in the {@code Locale} obtained from a
* {@code Builder} is always normalized to upper case.
*
* @param region the region
* @return This builder.
* @throws IllformedLocaleException if {@code region} is ill-formed
*/
public Builder setRegion(String region) {
try {
localeBuilder.setRegion(region);
} catch (LocaleSyntaxException e) {
throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
}
return this;
}
/**
* Sets the variant. If variant is null or the empty string, the
* variant in this {@code Builder} is removed. Otherwise, it
* must consist of one or more {@linkplain Locale##def_variant well-formed}
* subtags, or an exception is thrown.
*
* Note: This method checks if {@code variant}
* satisfies the IETF BCP 47 variant subtag's syntax requirements,
* and normalizes the value to lowercase letters. However,
* the {@code Locale} class does not impose any syntactic
* restriction on variant, and the variant value in
* {@code Locale} is case sensitive. To set such a variant,
* use {@link #of(String, String, String)}.
*
* @param variant the variant
* @return This builder.
* @throws IllformedLocaleException if {@code variant} is ill-formed
* @see Locale#of(String, String, String)
*/
public Builder setVariant(String variant) {
try {
localeBuilder.setVariant(variant);
} catch (LocaleSyntaxException e) {
throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
}
return this;
}
/**
* Sets the extension for the given key. If the value is null or the
* empty string, the extension is removed. Otherwise, the extension
* must be {@linkplain Locale##def_extensions well-formed} or an exception
* is thrown.
*
* Note: The key {@link #UNICODE_LOCALE_EXTENSION
* UNICODE_LOCALE_EXTENSION} ('u') is used for the Unicode locale extension.
* Setting a value for this key replaces any existing Unicode locale key/type
* pairs with those defined in the extension.
*
* Note: The key {@link #PRIVATE_USE_EXTENSION
* PRIVATE_USE_EXTENSION} ('x') is used for the private use code. To be
* well-formed, the value for this key needs only to have subtags of one to
* eight alphanumeric characters, not two to eight as in the general case.
*
* @param key the extension key
* @param value the extension value
* @return This builder.
* @throws IllformedLocaleException if {@code key} is illegal
* or {@code value} is ill-formed
* @see #setUnicodeLocaleKeyword(String, String)
*/
public Builder setExtension(char key, String value) {
try {
localeBuilder.setExtension(key, value);
} catch (LocaleSyntaxException e) {
throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
}
return this;
}
/**
* Sets the Unicode locale keyword type for the given key. If the type
* is null, the Unicode keyword is removed. Otherwise, the key must be
* non-null and both key and type must be {@linkplain
* Locale##def_locale_extension well-formed} or an exception is thrown.
*
* Keys and types are converted to lower case.
*
* Note:Setting the 'u' extension via {@link #setExtension(char, String)}
* replaces all Unicode locale keywords with those defined in the
* extension.
*
* @param key the Unicode locale key
* @param type the Unicode locale type
* @return This builder.
* @throws IllformedLocaleException if {@code key} or {@code type}
* is ill-formed
* @throws NullPointerException if {@code key} is null
* @see #setExtension(char, String)
*/
public Builder setUnicodeLocaleKeyword(String key, String type) {
try {
localeBuilder.setUnicodeLocaleKeyword(key, type);
} catch (LocaleSyntaxException e) {
throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
}
return this;
}
/**
* Adds a unicode locale attribute, if not already present, otherwise
* has no effect. The attribute must not be null and must be
* {@linkplain Locale##def_locale_extension well-formed} or an exception
* is thrown.
*
* @param attribute the attribute
* @return This builder.
* @throws NullPointerException if {@code attribute} is null
* @throws IllformedLocaleException if {@code attribute} is ill-formed
* @see #setExtension(char, String)
*/
public Builder addUnicodeLocaleAttribute(String attribute) {
try {
localeBuilder.addUnicodeLocaleAttribute(attribute);
} catch (LocaleSyntaxException e) {
throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
}
return this;
}
/**
* Removes a unicode locale attribute, if present, otherwise has no
* effect. The attribute must not be null and must be
* {@linkplain Locale##def_locale_extension well-formed} or an exception
* is thrown.
*
* Attribute comparison for removal is case-insensitive.
*
* @param attribute the attribute
* @return This builder.
* @throws NullPointerException if {@code attribute} is null
* @throws IllformedLocaleException if {@code attribute} is ill-formed
* @see #setExtension(char, String)
*/
public Builder removeUnicodeLocaleAttribute(String attribute) {
Objects.requireNonNull(attribute);
try {
localeBuilder.removeUnicodeLocaleAttribute(attribute);
} catch (LocaleSyntaxException e) {
throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
}
return this;
}
/**
* Resets the builder to its initial, empty state.
*
* @return This builder.
*/
public Builder clear() {
localeBuilder.clear();
return this;
}
/**
* Resets the extensions to their initial, empty state.
* Language, script, region and variant are unchanged.
*
* @return This builder.
* @see #setExtension(char, String)
*/
public Builder clearExtensions() {
localeBuilder.clearExtensions();
return this;
}
/**
* Returns an instance of {@code Locale} obtained from the fields set
* on this builder.
*
* This applies the conversions listed in {@link #forLanguageTag(String)}
* when constructing a Locale. (Legacy tags are handled in
* {@link #setLanguageTag(String)}.)
*
* @return A Locale.
*/
public Locale build() {
BaseLocale baseloc = localeBuilder.getBaseLocale();
LocaleExtensions extensions = localeBuilder.getLocaleExtensions();
if (extensions == null && !baseloc.getVariant().isEmpty()) {
extensions = getCompatibilityExtensions(baseloc.getLanguage(), baseloc.getScript(),
baseloc.getRegion(), baseloc.getVariant());
}
return Locale.getInstance(baseloc, extensions);
}
}
/**
* This enum provides constants to select a filtering mode for locale
* matching. Refer to RFC 4647
* Matching of Language Tags for details.
*
* As an example, think of two Language Priority Lists each of which
* includes only one language range and a set of following language tags:
*
* There are two types of language ranges: basic and extended. In RFC
* 4647, the syntax of language ranges is expressed in
* ABNF as follows:
* This is equivalent to {@code LanguageRange(range, MAX_WEIGHT)}.
*
* @param range a language range
* @throws NullPointerException if the given {@code range} is
* {@code null}
* @throws IllegalArgumentException if the given {@code range} does not
* comply with the syntax of the language range mentioned in RFC 4647
*/
public LanguageRange(String range) {
this(range, MAX_WEIGHT);
}
/**
* Constructs a {@code LanguageRange} using the given {@code range} and
* {@code weight}. Note that no validation is done against the IANA
* Language Subtag Registry at time of construction.
*
* @param range a language range
* @param weight a weight value between {@code MIN_WEIGHT} and
* {@code MAX_WEIGHT}
* @throws NullPointerException if the given {@code range} is
* {@code null}
* @throws IllegalArgumentException if the given {@code range} does not
* comply with the syntax of the language range mentioned in RFC 4647
* or if the given {@code weight} is less than {@code MIN_WEIGHT}
* or greater than {@code MAX_WEIGHT}
*/
public LanguageRange(String range, double weight) {
Objects.requireNonNull(range);
if (weight < MIN_WEIGHT || weight > MAX_WEIGHT) {
throw new IllegalArgumentException("weight=" + weight);
}
range = range.toLowerCase(Locale.ROOT);
// Do syntax check.
boolean isIllFormed = false;
String[] subtags = range.split("-");
if (range.endsWith("-") ||
isSubtagIllFormed(subtags[0], true)) {
isIllFormed = true;
} else {
for (int i = 1; i < subtags.length; i++) {
if (isSubtagIllFormed(subtags[i], false)) {
isIllFormed = true;
break;
}
}
}
if (isIllFormed) {
throw new IllegalArgumentException("range=" + range);
}
this.range = range;
this.weight = weight;
}
private static boolean isSubtagIllFormed(String subtag,
boolean isFirstSubtag) {
if (subtag.isEmpty() || subtag.length() > 8) {
return true;
} else if (subtag.equals("*")) {
return false;
}
char[] charArray = subtag.toCharArray();
if (isFirstSubtag) { // ALPHA
for (char c : charArray) {
if (c < 'a' || c > 'z') {
return true;
}
}
} else { // ALPHA / DIGIT
for (char c : charArray) {
if (c < '0' || (c > '9' && c < 'a') || c > 'z') {
return true;
}
}
}
return false;
}
/**
* Returns the language range of this {@code LanguageRange}.
*
* @return the language range.
*/
public String getRange() {
return range;
}
/**
* Returns the weight of this {@code LanguageRange}.
*
* @return the weight value.
*/
public double getWeight() {
return weight;
}
/**
* Parses the given {@code ranges} to generate a Language Priority List.
*
* This method performs a syntactic check for each language range in
* the given {@code ranges} but doesn't do validation using the IANA
* Language Subtag Registry.
*
* The {@code ranges} to be given can take one of the following
* forms:
*
* Unlike a weighted list, language ranges in a prioritized list
* are sorted in the descending order based on its priority. The first
* language range has the highest priority and meets the user's
* preference most.
*
* In either case, language ranges are sorted in descending order in
* the Language Priority List based on priority or weight. If a
* language range appears in the given {@code ranges} more than once,
* only the first one is included on the Language Priority List.
*
* The returned list consists of language ranges from the given
* {@code ranges} and their equivalents found in the IANA Language
* Subtag Registry. For example, if the given {@code ranges} is
* {@code "Accept-Language: iw,en-us;q=0.7,en;q=0.3"}, the elements in
* the list to be returned are:
*
* In the map, a key represents a language range whereas a value is
* a list of equivalents of it. {@code '*'} cannot be used in the map.
* Each equivalent language range has the same weight value as its
* original language range.
*
* For example, if a user's Language Priority List consists of five
* language ranges ({@code "zh"}, {@code "zh-CN"}, {@code "en"},
* {@code "zh-TW"}, and {@code "zh-HK"}), the newly generated Language
* Priority List which is customized using the above map example will
* consists of {@code "zh"}, {@code "zh-Hans"}, {@code "zh-CN"},
* {@code "zh-Hans-CN"}, {@code "en"}, {@code "zh-TW"}, and
* {@code "zh-HK"}.
*
* {@code "zh-HK"} and {@code "zh-TW"} aren't converted to
* {@code "zh-Hans-HK"} nor {@code "zh-Hans-TW"} even if they are
* included in the Language Priority List. In this example, mapping
* is used to clearly distinguish Simplified Chinese and Traditional
* Chinese.
*
* If the {@code "zh"}-to-{@code "zh"} mapping isn't included in the
* map, a simple replacement will be performed and the customized list
* won't include {@code "zh"} and {@code "zh-CN"}.
*
* @param priorityList user's Language Priority List
* @param map a map containing information to customize language ranges
* @return a new Language Priority List with customization. The list is
* modifiable.
* @throws NullPointerException if {@code priorityList} is {@code null}
* @see #parse(String, Map)
*/
public static List
*
*
* @deprecated Locale constructors have been deprecated. See {@linkplain ##ObtainingLocale
* Obtaining a Locale} for other options.
*
* @param language An ISO 639 alpha-2 or alpha-3 language code, or a language subtag
* up to 8 characters in length. See the {@code Locale} class description about
* valid language values.
* @param country An ISO 3166 alpha-2 country code or a UN M.49 numeric-3 area code.
* See the {@code Locale} class description about valid country values.
* @param variant Any arbitrary value used to indicate a variation of a {@code Locale}.
* See the {@code Locale} class description for the details.
* @throws NullPointerException thrown if any argument is null.
*/
@Deprecated(since="19")
public Locale(String language, String country, String variant) {
if (language == null || country == null || variant == null) {
throw new NullPointerException();
}
baseLocale = BaseLocale.getInstance(convertOldISOCodes(language), "", country, variant);
localeExtensions = getCompatibilityExtensions(language, "", country, variant);
}
/**
* Construct a locale from language and country.
* This constructor normalizes the language value to lowercase and
* the country value to uppercase.
* @implNote
*
*
*
* @deprecated Locale constructors have been deprecated. See {@linkplain
* ##ObtainingLocale Obtaining a Locale} for other options.
*
* @param language An ISO 639 alpha-2 or alpha-3 language code, or a language subtag
* up to 8 characters in length. See the {@code Locale} class description about
* valid language values.
* @param country An ISO 3166 alpha-2 country code or a UN M.49 numeric-3 area code.
* See the {@code Locale} class description about valid country values.
* @throws NullPointerException thrown if either argument is null.
*/
@Deprecated(since="19")
public Locale(String language, String country) {
this(language, country, "");
}
/**
* Construct a locale from a language code.
* This constructor normalizes the language value to lowercase.
* @implNote
*
*
*
* @deprecated Locale constructors have been deprecated. See {@linkplain
* ##ObtainingLocale Obtaining a Locale} for other options.
*
* @param language An ISO 639 alpha-2 or alpha-3 language code, or a language subtag
* up to 8 characters in length. See the {@code Locale} class description about
* valid language values.
* @throws NullPointerException thrown if argument is null.
* @since 1.4
*/
@Deprecated(since="19")
public Locale(String language) {
this(language, "", "");
}
/**
* Obtains a locale from language, country and variant.
* This method normalizes the language value to lowercase and
* the country value to uppercase.
* @implNote
*
*
*
* @param language A language code. See the {@code Locale} class description of
* {@linkplain ##def_language language} values.
* @param country A country code. See the {@code Locale} class description of
* {@linkplain ##def_region country} values.
* @param variant Any arbitrary value used to indicate a variation of a {@code Locale}.
* See the {@code Locale} class description of {@linkplain ##def_variant
* variant} values.
* @throws NullPointerException thrown if any argument is null.
* @return A {@code Locale} object
* @since 19
*/
public static Locale of(String language, String country, String variant) {
return getInstance(language, "", country, variant, null);
}
/**
* Obtains a locale from language and country.
* This method normalizes the language value to lowercase and
* the country value to uppercase.
* @implNote
*
*
*
* @param language A language code. See the {@code Locale} class description of
* {@linkplain ##def_language language} values.
* @param country A country code. See the {@code Locale} class description of
* {@linkplain ##def_region country} values.
* @throws NullPointerException thrown if either argument is null.
* @return A {@code Locale} object
* @since 19
*/
public static Locale of(String language, String country) {
return getInstance(language, "", country, "", null);
}
/**
* Obtains a locale from a language code.
* This method normalizes the language value to lowercase.
* @implNote
*
*
*
* @param language A language code. See the {@code Locale} class description of
* {@linkplain ##def_language language} values.
* @throws NullPointerException thrown if argument is null.
* @return A {@code Locale} object
* @since 19
*/
public static Locale of(String language) {
return getInstance(language, "", "", "", null);
}
/**
* Returns a {@code Locale} constructed from the given
* {@code language}, {@code country} and
* {@code variant}. If the same {@code Locale} instance
* is available in the cache, then that instance is
* returned. Otherwise, a new {@code Locale} instance is
* created and cached.
*
* @param language lowercase 2 to 8 language code.
* @param country uppercase two-letter ISO-3166 code and numeric-3 UN M.49 area code.
* @param variant vendor and browser specific code. See class description.
* @return the {@code Locale} instance requested
* @throws NullPointerException if any argument is null.
*/
static Locale getInstance(String language, String country, String variant) {
return getInstance(language, "", country, variant, null);
}
static Locale getInstance(String language, String script, String country,
String variant, LocaleExtensions extensions) {
if (language== null || script == null || country == null || variant == null) {
throw new NullPointerException();
}
if (extensions == null) {
extensions = getCompatibilityExtensions(language, script, country, variant);
}
BaseLocale baseloc = BaseLocale.getInstance(convertOldISOCodes(language), script, country, variant);
return getInstance(baseloc, extensions);
}
static Locale getInstance(BaseLocale baseloc, LocaleExtensions extensions) {
if (extensions == null) {
Locale locale = CONSTANT_LOCALES.get(baseloc);
if (locale != null) {
return locale;
}
return LocaleCache.cache(baseloc);
} else {
LocaleKey key = new LocaleKey(baseloc, extensions);
return LocaleCache.cache(key);
}
}
private static final class LocaleCache implements Function
*
*
* @return An array of ISO 639 two-letter language codes.
*/
public static String[] getISOLanguages() {
String[] languages = Locale.isoLanguages;
if (languages == null) {
Locale.isoLanguages = languages = getISO2Table(LocaleISOData.isoLanguageTable);
}
String[] result = new String[languages.length];
System.arraycopy(languages, 0, result, 0, languages.length);
return result;
}
private static String[] getISO2Table(String table) {
int len = table.length() / 5;
String[] isoTable = new String[len];
for (int i = 0, j = 0; i < len; i++, j += 5) {
isoTable[i] = table.substring(j, j + 2);
}
return isoTable;
}
/**
* Returns the language code of this Locale.
*
* @implNote This method returns the new forms for the obsolete ISO 639
* codes ("iw", "ji", and "in"). See {@linkplain ##legacy_language_codes
* Legacy language codes} for more information.
*
* @return The language code, or the empty string if none is defined.
* @see #getDisplayLanguage
*/
public String getLanguage() {
return baseLocale.getLanguage();
}
/**
* Returns the script for this locale, which should
* either be the empty string or an ISO 15924 4-letter script
* code. The first letter is uppercase and the rest are
* lowercase, for example, 'Latn', 'Cyrl'.
*
* @return The script code, or the empty string if none is defined.
* @see #getDisplayScript
* @since 1.7
*/
public String getScript() {
return baseLocale.getScript();
}
/**
* 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.
*
* @return The country/region code, or the empty string if none is defined.
* @see #getDisplayCountry
*/
public String getCountry() {
return baseLocale.getRegion();
}
/**
* Returns the variant code for this locale.
*
* @return The variant code, or the empty string if none is defined.
* @see #getDisplayVariant
*/
public String getVariant() {
return baseLocale.getVariant();
}
/**
* Returns {@code true} if this {@code Locale} has any {@linkplain ##def_extensions
* extensions}.
*
* @return {@code true} if this {@code Locale} has any extensions
* @since 1.8
*/
public boolean hasExtensions() {
return localeExtensions != null;
}
/**
* Returns a copy of this {@code Locale} with no {@linkplain ##def_extensions
* extensions}. If this {@code Locale} has no extensions, this {@code Locale}
* is returned.
*
* @return a copy of this {@code Locale} with no extensions, or {@code this}
* if {@code this} has no extensions
* @since 1.8
*/
public Locale stripExtensions() {
return hasExtensions() ? Locale.getInstance(baseLocale, null) : this;
}
/**
* Returns the extension (or private use) value associated with
* the specified key, or null if there is no extension
* associated with the key. To be well-formed, the key must be one
* of {@code [0-9A-Za-z]}. Keys are case-insensitive, so
* for example 'z' and 'Z' represent the same extension.
*
* @param key the extension key
* @return The extension, or null if this locale defines no
* extension for the specified key.
* @throws IllegalArgumentException if key is not well-formed
* @see #PRIVATE_USE_EXTENSION
* @see #UNICODE_LOCALE_EXTENSION
* @since 1.7
*/
public String getExtension(char key) {
if (!LocaleExtensions.isValidKey(key)) {
throw new IllegalArgumentException("Ill-formed extension key: " + key);
}
return hasExtensions() ? localeExtensions.getExtensionValue(key) : null;
}
/**
* Returns the set of extension keys associated with this locale, or the
* empty set if it has no extensions. The returned set is unmodifiable.
* The keys will all be lower-case.
*
* @return The set of extension keys, or the empty set if this locale has
* no extensions.
* @since 1.7
*/
public Set
* 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. Extensions and private use subtags
* will be in canonical order as explained in {@link #toLanguageTag}.
*
*
*
*
* @return A string representation of the Locale, for debugging.
* @see #getDisplayName
* @see #toLanguageTag
*/
@Override
public final String toString() {
boolean l = !baseLocale.getLanguage().isEmpty();
boolean s = !baseLocale.getScript().isEmpty();
boolean r = !baseLocale.getRegion().isEmpty();
boolean v = !baseLocale.getVariant().isEmpty();
boolean e = localeExtensions != null && !localeExtensions.getID().isEmpty();
StringBuilder result = new StringBuilder(baseLocale.getLanguage());
if (r || (l && (v || s || e))) {
result.append('_')
.append(baseLocale.getRegion()); // This may just append '_'
}
if (v && (l || r)) {
result.append('_')
.append(baseLocale.getVariant());
}
if (s && (l || r)) {
result.append("_#")
.append(baseLocale.getScript());
}
if (e && (l || r)) {
result.append('_');
if (!s) {
result.append('#');
}
result.append(localeExtensions.getID());
}
return result.toString();
}
/**
* Returns a well-formed IETF BCP 47 language tag representing
* this locale.
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
* 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 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
* 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.
*
* @return The name of the locale appropriate to display.
*/
public final String getDisplayName() {
return getDisplayName(getDefault(Category.DISPLAY));
}
/**
* Returns a name for the locale that is appropriate for display
* to the user. This will be the values returned by
* getDisplayLanguage(), getDisplayScript(), getDisplayCountry(),
* getDisplayVariant(), and optional {@linkplain ##def_locale_extension
* Unicode extensions} assembled into a single string. The non-empty
* values are used in order, with the second and subsequent names in
* parentheses. For example:
*
* language (country(, extension)*)
* language (variant(, extension)*)
* script (country(, extension)*)
* country (extension)*
*
* 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.
*
* @param inLocale The locale for which to retrieve the display name.
* @return The name of the locale appropriate to display.
* @throws NullPointerException if {@code inLocale} is {@code null}
*/
public String getDisplayName(Locale inLocale) {
LocaleResources lr = LocaleProviderAdapter
.getResourceBundleBased()
.getLocaleResources(inLocale);
String languageName = getDisplayLanguage(inLocale);
String scriptName = getDisplayScript(inLocale);
String countryName = getDisplayCountry(inLocale);
String[] variantNames = getDisplayVariantArray(inLocale);
// Get the localized patterns for formatting a display name.
String displayNamePattern = lr.getLocaleName("DisplayNamePattern");
String listCompositionPattern = lr.getLocaleName("ListCompositionPattern");
// The display name consists of a main name, followed by qualifiers.
// Typically, the format is "MainName (Qualifier, Qualifier)" but this
// depends on what pattern is stored in the display locale.
String mainName;
String[] qualifierNames;
// The main name is the language, or if there is no language, the script,
// then if no script, the country. If there is no language/script/country
// (an anomalous situation) then the display name is simply the variant's
// display name.
if (languageName.isEmpty() && scriptName.isEmpty() && countryName.isEmpty()) {
if (variantNames.length == 0) {
return "";
} else {
return formatList(variantNames, listCompositionPattern);
}
}
ArrayList
* language (country(, extension)*)
* language (variant(, extension)*)
* script (country(, extension)*)
* country (extension)*
*
*
*
* @param locale the locale
* @return This builder.
* @throws IllformedLocaleException if {@code locale} has
* any ill-formed fields.
* @throws NullPointerException if {@code locale} is null.
*/
public Builder setLocale(Locale locale) {
try {
localeBuilder.setLocale(locale.baseLocale, locale.localeExtensions);
} catch (LocaleSyntaxException e) {
throw new IllformedLocaleException(e.getMessage(), e.getErrorIndex());
}
return this;
}
/**
* Resets the Builder to match the provided IETF BCP 47
* language tag. Discards the existing state. Null and the
* empty string cause the builder to be reset, like {@link
* #clear}. Legacy tags (see {@link
* Locale#forLanguageTag(String)}) are converted to their canonical
* form before being processed. Otherwise, the language tag
* must be well-formed (see {@link Locale}) or an exception is
* thrown (unlike {@code Locale.forLanguageTag}, which
* just discards ill-formed and following portions of the
* tag).
*
* @param languageTag the language tag
* @return This builder.
* @throws IllformedLocaleException if {@code languageTag} is ill-formed
* @see Locale#forLanguageTag(String)
*/
public Builder setLanguageTag(String languageTag) {
LanguageTag tag = LanguageTag.parse(
languageTag, new ParsePosition(0), false);
localeBuilder.setLanguageTag(tag);
return this;
}
/**
* Sets the language. If {@code language} is the empty string or
* null, the language in this {@code Builder} is removed. Otherwise,
* the language must be {@linkplain Locale##def_language well-formed}
* or an exception is thrown.
*
*
* de (German)
* de-DE (German, Germany)
* de-Deva (German, in Devanagari script)
* de-Deva-DE (German, in Devanagari script, Germany)
* de-DE-1996 (German, Germany, orthography of 1996)
* de-Latn-DE (German, in Latin script, Germany)
* de-Latn-DE-1996 (German, in Latin script, Germany, orthography of 1996)
*
*
* The filtering method will behave as follows:
*
*
*
*
* @spec https://www.rfc-editor.org/info/rfc4647 RFC 4647: Matching of Language Tags
* @see #filter(List, Collection, FilteringMode)
* @see #filterTags(List, Collection, FilteringMode)
*
* @since 1.8
*/
public static enum FilteringMode {
/**
* Specifies automatic filtering mode based on the given Language
* Priority List consisting of language ranges. If all of the ranges
* are basic, basic filtering is selected. Otherwise, extended
* filtering is selected.
*/
AUTOSELECT_FILTERING,
/**
* Specifies extended filtering.
*/
EXTENDED_FILTERING,
/**
* Specifies basic filtering: Note that any extended language ranges
* included in the given Language Priority List are ignored.
*/
IGNORE_EXTENDED_RANGES,
/**
* Specifies basic filtering: If any extended language ranges are
* included in the given Language Priority List, they are mapped to the
* basic language range. Specifically, a language range starting with a
* subtag {@code "*"} is treated as a language range {@code "*"}. For
* example, {@code "*-US"} is treated as {@code "*"}. If {@code "*"} is
* not the first subtag, {@code "*"} and extra {@code "-"} are removed.
* For example, {@code "ja-*-JP"} is mapped to {@code "ja-JP"}.
*/
MAP_EXTENDED_RANGES,
/**
* Specifies basic filtering: If any extended language ranges are
* included in the given Language Priority List, the list is rejected
* and the filtering method throws {@link IllegalArgumentException}.
*/
REJECT_EXTENDED_RANGES
};
/**
* This class expresses a Language Range defined in
* RFC 4647 Matching of
* Language Tags. A language range is an identifier which is used to
* select language tag(s) meeting specific requirements by using the
* mechanisms described in {@linkplain Locale##LocaleMatching Locale
* Matching}. A list which represents a user's preferences and consists
* of language ranges is called a Language Priority List.
*
*
*
*
*
* Filtering Mode
* Language Priority List: {@code "de-DE"}
* Language Priority List: {@code "de-*-DE"}
*
*
*
* {@link FilteringMode#AUTOSELECT_FILTERING AUTOSELECT_FILTERING}
*
*
* Performs basic filtering and returns {@code "de-DE"} and
* {@code "de-DE-1996"}.
*
*
* Performs extended filtering and returns {@code "de-DE"},
* {@code "de-Deva-DE"}, {@code "de-DE-1996"}, {@code "de-Latn-DE"}, and
* {@code "de-Latn-DE-1996"}.
*
*
*
*
* {@link FilteringMode#EXTENDED_FILTERING EXTENDED_FILTERING}
*
*
* Performs extended filtering and returns {@code "de-DE"},
* {@code "de-Deva-DE"}, {@code "de-DE-1996"}, {@code "de-Latn-DE"}, and
* {@code "de-Latn-DE-1996"}.
*
* Same as above.
*
*
*
* {@link FilteringMode#IGNORE_EXTENDED_RANGES IGNORE_EXTENDED_RANGES}
*
*
* Performs basic filtering and returns {@code "de-DE"} and
* {@code "de-DE-1996"}.
*
*
* Performs basic filtering and returns {@code null} because
* nothing matches.
*
*
*
*
* {@link FilteringMode#MAP_EXTENDED_RANGES MAP_EXTENDED_RANGES}
*
* Same as above.
*
* Performs basic filtering and returns {@code "de-DE"} and
* {@code "de-DE-1996"} because {@code "de-*-DE"} is mapped to
* {@code "de-DE"}.
*
*
*
*
*
* {@link FilteringMode#REJECT_EXTENDED_RANGES REJECT_EXTENDED_RANGES}
*
* Same as above.
*
* Throws {@link IllegalArgumentException} because {@code "de-*-DE"} is
* not a valid basic language range.
*
*
*
* For example, {@code "en"} (English), {@code "ja-JP"} (Japanese, Japan),
* {@code "*"} (special language range which matches any language tag) are
* basic language ranges, whereas {@code "*-CH"} (any languages,
* Switzerland), {@code "es-*"} (Spanish, any regions), and
* {@code "zh-Hant-*"} (Traditional Chinese, any regions) are extended
* language ranges.
*
* @spec https://www.rfc-editor.org/info/rfc4234 RFC 4234: Augmented BNF for Syntax Specifications: ABNF
* @spec https://www.rfc-editor.org/info/rfc4647 RFC 4647: Matching of Language Tags
* @see #filter(List, Collection, FilteringMode)
* @see #filterTags(List, Collection, FilteringMode)
* @see #lookup(List, Collection)
* @see #lookupTag(List, Collection)
*
* @since 1.8
*/
public static final class LanguageRange {
/**
* A constant holding the maximum value of weight, 1.0, which indicates
* that the language range is a good fit for the user.
*/
public static final double MAX_WEIGHT = 1.0;
/**
* A constant holding the minimum value of weight, 0.0, which indicates
* that the language range is not a good fit for the user.
*/
public static final double MIN_WEIGHT = 0.0;
private final String range;
private final double weight;
private @Stable int hash;
/**
* Constructs a {@code LanguageRange} using the given {@code range}.
* Note that no validation is done against the IANA Language Subtag
* Registry at time of construction.
*
*
* basic-language-range = (1*8ALPHA *("-" 1*8alphanum)) / "*"
* extended-language-range = (1*8ALPHA / "*")
* *("-" (1*8alphanum / "*"))
* alphanum = ALPHA / DIGIT
*
*
* "Accept-Language: ja,en;q=0.4" (weighted list with Accept-Language prefix)
* "ja,en;q=0.4" (weighted list)
* "ja,en" (prioritized list)
*
*
* In a weighted list, each language range is given a weight value.
* The weight value is identical to the "quality value" in
* RFC 2616, and it
* expresses how much the user prefers the language. A weight value is
* specified after a corresponding language range followed by
* {@code ";q="}, and the default weight value is {@code MAX_WEIGHT}
* when it is omitted.
*
*
* Range Weight
* "iw" (older tag for Hebrew) 1.0
* "he" (new preferred code for Hebrew) 1.0
* "en-us" (English, United States) 0.7
* "en" (English) 0.3
*
*
* Two language ranges, {@code "iw"} and {@code "he"}, have the same
* highest priority in the list. By adding {@code "he"} to the user's
* Language Priority List, locale-matching method can find Hebrew as a
* matching locale (or language tag) even if the application or system
* offers only {@code "he"} as a supported locale (or language tag).
*
* @param ranges a list of comma-separated language ranges or a list of
* language ranges in the form of the "Accept-Language" header
* defined in RFC
* 2616
* @return a Language Priority List consisting of language ranges
* included in the given {@code ranges} and their equivalent
* language ranges if available. The list is modifiable.
* @throws NullPointerException if {@code ranges} is null
* @throws IllegalArgumentException if a language range or a weight
* found in the given {@code ranges} is ill-formed
* @spec https://www.rfc-editor.org/info/rfc2616 RFC 2616: Hypertext Transfer Protocol -- HTTP/1.1
*/
public static List
* An example of map:
* Key Value
* "zh" (Chinese) "zh",
* "zh-Hans"(Simplified Chinese)
* "zh-HK" (Chinese, Hong Kong) "zh-HK"
* "zh-TW" (Chinese, Taiwan) "zh-TW"
*
*
* The customization is performed after modification using the IANA
* Language Subtag Registry.
*
*