- All Implemented Interfaces:
Serializable
,Cloneable
Locale
object represents a specific geographical, political,
or cultural region. An operation that requires a Locale
to perform
its task is called locale-sensitive and uses the Locale
to tailor information for the user. For example, displaying a number
is a locale-sensitive operation— the number should be formatted
according to the customs and conventions of the user's native country,
region, or culture.
The Locale
class implements IETF BCP 47 which is composed of
RFC 4647 "Matching of Language
Tags" and RFC 5646 "Tags
for Identifying Languages" with support for the LDML (UTS#35, "Unicode
Locale Data Markup Language") BCP 47-compatible extensions for locale data
exchange.
A Locale
object logically consists of the fields
described below.
- language
- ISO 639 alpha-2 or alpha-3 language code, or registered
language subtags up to 8 alpha letters (for future enhancements).
When a language has both an alpha-2 code and an alpha-3 code, the
alpha-2 code must be used. You can find a full list of valid
language codes in the IANA Language Subtag Registry (search for
"Type: language"). The language field is case insensitive, but
Locale
always canonicalizes to lower case. - Well-formed language values have the form
[a-zA-Z]{2,8}
. Note that this is not the full BCP47 language production, since it excludes extlang. They are not needed since modern three-letter language codes replace them. - Example: "en" (English), "ja" (Japanese), "kok" (Konkani)
- script
- ISO 15924 alpha-4 script code. You can find a full list of
valid script codes in the IANA Language Subtag Registry (search
for "Type: script"). The script field is case insensitive, but
Locale
always canonicalizes to title case (the first letter is upper case and the rest of the letters are lower case). - Well-formed script values have the form
[a-zA-Z]{4}
- Example: "Latn" (Latin), "Cyrl" (Cyrillic)
- country (region)
- ISO 3166 alpha-2 country code or UN M.49 numeric-3 area code.
You can find a full list of valid country and region codes in the
IANA Language Subtag Registry (search for "Type: region"). The
country (region) field is case insensitive, but
Locale
always canonicalizes to upper case. - Well-formed country/region values have
the form
[a-zA-Z]{2} | [0-9]{3}
- Example: "US" (United States), "FR" (France), "029" (Caribbean)
- variant
- Any arbitrary value used to indicate a variation of a
Locale
. Where there are two or more variant values each indicating its own semantics, these values should be ordered by importance, with most important first, separated by underscore('_'). The variant field is case sensitive. - Note: IETF BCP 47 places syntactic restrictions on variant
subtags. Also BCP 47 subtags are strictly used to indicate
additional variations that define a language or its dialects that
are not covered by any combinations of language, script and
region subtags. You can find a full list of valid variant codes
in the IANA Language Subtag Registry (search for "Type: variant").
However, the variant field in
Locale
has historically been used for any kind of variation, not just language variations. For example, some supported variants available in Java SE Runtime Environments indicate alternative cultural behaviors such as calendar type or number script. In BCP 47 this kind of information, which does not identify the language, is supported by extension subtags or private use subtags. - Well-formed variant values have the form
SUBTAG (('_'|'-') SUBTAG)*
whereSUBTAG = [0-9][0-9a-zA-Z]{3} | [0-9a-zA-Z]{5,8}
. (Note: BCP 47 only uses hyphen ('-') as a delimiter, this is more lenient). - Example: "polyton" (Polytonic Greek), "POSIX"
- extensions
- A map from single character keys to string values, indicating
extensions apart from language identification. The extensions in
Locale
implement the semantics and syntax of BCP 47 extension subtags and private use subtags. The extensions are case insensitive, butLocale
canonicalizes all extension keys and values to lower case. Note that extensions cannot have empty values. - Well-formed keys are single characters from the set
[0-9a-zA-Z]
. Well-formed values have the 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 provide any validation features. The Builder
only checks if an individual field satisfies the syntactic
requirement (is well-formed), but does not validate the value
itself. See Locale.Builder
for details.
Unicode locale/language extension
UTS#35, "Unicode Locale Data Markup Language" defines optional attributes and keywords to override or refine the default behavior associated with a locale. A keyword is represented by a pair of key and type. For example, "nu-thai" indicates that Thai local digits (value:"thai") should be used for formatting numbers (key:"nu").
The keywords are mapped to a BCP 47 extension value using the
extension key 'u' (UNICODE_LOCALE_EXTENSION
). The above
example, "nu-thai", becomes the extension "u-nu-thai".
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(java.lang.String)
which allow you to access Unicode
locale attributes and key/type pairs directly. When represented as
a string, the Unicode Locale Extension lists attributes
alphabetically, followed by key/type sequences with keys listed
alphabetically (the order of subtags comprising a key's type is
fixed when the type is defined)
A well-formed locale key has the form
[0-9a-zA-Z]{2}
. A well-formed locale type has the
form "" | [0-9a-zA-Z]{3,8} ('-' [0-9a-zA-Z]{3,8})*
(it
can be empty, or a series of subtags 3-8 alphanums in length). A
well-formed locale attribute has the form
[0-9a-zA-Z]{3,8}
(it is a single subtag with the same
form as a locale type subtag).
The Unicode locale extension specifies optional behavior in locale-sensitive services. Although the LDML specification defines various keys and values, actual locale-sensitive service implementations in a Java Runtime Environment might not support any particular Unicode locale attributes or key/type pairs.
Obtaining a Locale
There are several ways to obtain a Locale
object.
Builder
Using Locale.Builder
you can construct a Locale
object
that conforms to BCP 47 syntax.
Factory Methods
The method forLanguageTag(java.lang.String)
obtains a Locale
object for a well-formed BCP 47 language tag. The method
of(String, String, String)
and its overloads obtain a
Locale
object from given language
, country
,
and/or variant
defined above.
Locale Constants
The Locale
class provides a number of convenient constants
that you can use to obtain Locale
objects for commonly used
locales. For example, Locale.US
is the Locale
object
for the United States.
Locale Matching
If an application or a system is internationalized and provides localized resources for multiple locales, it sometimes needs to find one or more locales (or language tags) which meet each user's specific preferences. Note that a term "language tag" is used interchangeably with "locale" in this locale matching documentation.
In order to do matching a user's preferred locales to a set of language tags, RFC 4647 Matching of Language Tags defines two mechanisms: filtering and lookup. Filtering is used to get all matching locales, whereas lookup is to choose the best matching locale. Matching is done case-insensitively. These matching mechanisms are described in the following sections.
A user's preference is called a Language Priority List and is
expressed as a list of language ranges. There are syntactically two types of
language ranges: basic and extended. See
Locale.LanguageRange
for details.
Filtering
The filtering operation returns all matching language tags. It is defined in RFC 4647 as follows: "In filtering, each language range represents the least specific language tag (that is, the language tag with fewest number of subtags) that is an acceptable match. All of the language tags in the matching set of tags will have an equal or greater number of subtags than the language range. Every non-wildcard subtag in the language range will appear in every one of the matching language tags."
There are two types of filtering: filtering for basic language ranges
(called "basic filtering") and filtering for extended language ranges
(called "extended filtering"). They may return different results by what
kind of language ranges are included in the given Language Priority List.
Locale.FilteringMode
is a parameter to specify how filtering should
be done.
Lookup
The lookup operation returns the best matching language tags. It is defined in RFC 4647 as follows: "By contrast with filtering, each language range represents the most specific tag that is an acceptable match. The first matching tag found, according to the user's priority, is considered the closest match and is the item returned."
For example, if a Language Priority List consists of two language ranges,
"zh-Hant-TW"
and "en-US"
, in prioritized order, lookup
method progressively searches the language tags below in order to find the
best matching language tag.
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.
Use of Locale
Once you've obtained a Locale
you can query it for information
about itself. Use getCountry
to get the country (or region)
code and getLanguage
to get the language code.
You can use getDisplayCountry
to get the
name of the country suitable for displaying to the user. Similarly,
you can use getDisplayLanguage
to get the name of
the language suitable for displaying to the user. Interestingly,
the getDisplayXXX
methods are themselves locale-sensitive
and have two versions: one that uses the default
DISPLAY
locale and one
that uses the locale specified as an argument.
The Java Platform provides a number of classes that perform locale-sensitive
operations. For example, the NumberFormat
class formats
numbers, currency, and percentages in a locale-sensitive manner. Classes
such as NumberFormat
have several convenience methods
for creating a default object of that type. For example, the
NumberFormat
class provides these three convenience methods
for creating a default NumberFormat
object:
NumberFormat.getInstance();
NumberFormat.getCurrencyInstance();
NumberFormat.getPercentInstance();
FORMAT
locale:
NumberFormat.getInstance(myLocale);
NumberFormat.getCurrencyInstance(myLocale);
NumberFormat.getPercentInstance(myLocale);
Locale
is the mechanism for identifying the kind of object
(NumberFormat
) that you would like to get. The locale is
just a mechanism for identifying objects,
not a container for the objects themselves.
Compatibility
In order to maintain compatibility, Locale's
constructors retain their behavior prior to the Java Runtime
Environment version 1.7. The same is largely true for the
toString
method. Thus Locale objects can continue to
be used as they were. In particular, clients who parse the output
of toString into language, country, and variant fields can continue
to do so (although this is strongly discouraged), although the
variant field will have additional information in it if script or
extensions are present.
In addition, BCP 47 imposes syntax restrictions that are not
imposed by Locale's constructors. This means that conversions
between some Locales and BCP 47 language tags cannot be made without
losing information. Thus toLanguageTag
cannot
represent the state of locales whose language, country, or variant
do not conform to BCP 47.
Because of these issues, it is recommended that clients migrate
away from constructing non-conforming locales and use the
forLanguageTag
and Locale.Builder
APIs instead.
Clients desiring a string representation of the complete locale can
then always rely on toLanguageTag
for this purpose.
Special cases
For compatibility reasons, two
non-conforming locales are treated as special cases. These are
ja_JP_JP
and th_TH_TH
. These are ill-formed
in BCP 47 since the variants are too short. To ease migration to BCP 47,
these are treated specially during construction. These two cases (and only
these) cause a constructor to generate an extension, all other values behave
exactly as they did prior to Java 7.
Java has used ja_JP_JP
to represent Japanese as used in
Japan together with the Japanese Imperial calendar. This is now
representable using a Unicode locale extension, by specifying the
Unicode locale key ca
(for "calendar") and type
japanese
. When the Locale constructor is called with the
arguments "ja", "JP", "JP", the extension "u-ca-japanese" is
automatically added.
Java has used th_TH_TH
to represent Thai as used in
Thailand together with Thai digits. This is also now representable using
a Unicode locale extension, by specifying the Unicode locale key
nu
(for "number") and value thai
. When the Locale
constructor is called with the arguments "th", "TH", "TH", the
extension "u-nu-thai" is automatically added.
Serialization
During serialization, writeObject writes all fields to the output stream, including extensions.
During deserialization, readResolve adds extensions as described in Special Cases, only for the two cases th_TH_TH and ja_JP_JP.
Legacy language codes
Locale's constructor has always converted three language codes to
their earlier, obsoleted forms: he
maps to iw
,
yi
maps to ji
, and id
maps to
in
. Since Java SE 17, this is no longer the case. Each
language maps to its new form; iw
maps to he
, ji
maps to yi
, and in
maps to id
.
For the backward compatible behavior, the system property
java.locale.useOldISOCodes
reverts the behavior
back to that of before Java SE 17. If the system property is set to
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 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
getLanguage
and toString
reflect the mapped
code, which depends on the java.locale.useOldISOCodes
system
property), but using the new codes in the BCP 47 language tag APIs (so
that toLanguageTag
reflects the new one). This
preserves the equivalence between Locales no matter which code or
API is used to construct them. Java's default resource bundle
lookup mechanism also implements this mapping, so that resources
can be named using either convention, see ResourceBundle.Control
.
Three-letter language/country(region) codes
The Locale constructors have always specified that the language and the country param be two characters in length, although in practice they have accepted any length. The specification has now been relaxed to allow language codes of two to eight characters and country (region) codes of two to three characters, and in particular, three-letter language codes and three-digit region codes as specified in the IANA Language Subtag Registry. For compatibility, the implementation still does not impose a length constraint.
- Since:
- 1.1
- External Specifications
- See Also:
-
Nested Class Summary
Modifier and TypeClassDescriptionstatic final class
Builder
is used to build instances ofLocale
from values configured by the setters.static enum
Enum for locale categories.static enum
This enum provides constants to select a filtering mode for locale matching.static enum
Enum for specifying the type defined in ISO 3166.static final class
This class expresses a Language Range defined in RFC 4647 Matching of Language Tags. -
Field Summary
Modifier and TypeFieldDescriptionstatic final Locale
Useful constant for country.static final Locale
Useful constant for country.static final Locale
Useful constant for country.static final Locale
Useful constant for language.static final Locale
Useful constant for language.static final Locale
Useful constant for country.static final Locale
Useful constant for language.static final Locale
Useful constant for language.static final Locale
Useful constant for country.static final Locale
Useful constant for language.static final Locale
Useful constant for country.static final Locale
Useful constant for country.static final Locale
Useful constant for language.static final Locale
Useful constant for country.static final Locale
Useful constant for language.static final Locale
Useful constant for country.static final char
The key for the private use extension ('x').static final Locale
Useful constant for the root locale.static final Locale
Useful constant for language.static final Locale
Useful constant for country.static final Locale
Useful constant for language.static final Locale
Useful constant for country.static final char
The key for Unicode locale extension ('u').static final Locale
Useful constant for country. -
Constructor Summary
ConstructorDescriptionDeprecated.Locale constructors have been deprecated.Deprecated.Locale constructors have been deprecated.Deprecated.Locale constructors have been deprecated. -
Method Summary
Modifier and TypeMethodDescriptionReturns a stream of installed locales.static String
caseFoldLanguageTag
(String languageTag) Returns a case folded IETF BCP 47 language tag.clone()
Overrides Cloneable.boolean
Returns true if this Locale is equal to another object.filter
(List<Locale.LanguageRange> priorityList, Collection<Locale> locales) Returns a list of matchingLocale
instances using the filtering mechanism defined in RFC 4647.filter
(List<Locale.LanguageRange> priorityList, Collection<Locale> locales, Locale.FilteringMode mode) Returns a list of matchingLocale
instances using the filtering mechanism defined in RFC 4647.filterTags
(List<Locale.LanguageRange> priorityList, Collection<String> tags) Returns a list of matching languages tags using the basic filtering mechanism defined in RFC 4647.filterTags
(List<Locale.LanguageRange> priorityList, Collection<String> tags, Locale.FilteringMode mode) Returns a list of matching languages tags using the basic filtering mechanism defined in RFC 4647.static Locale
forLanguageTag
(String languageTag) Returns a locale for the specified IETF BCP 47 language tag string.static Locale[]
Returns an array of installed locales.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
Gets the current value of the default locale for this instance of the Java Virtual Machine.static Locale
getDefault
(Locale.Category category) Gets the current value of the default locale for the specified Category for this instance of the Java Virtual Machine.final String
Returns a name for the locale's country that is appropriate for display to the user.getDisplayCountry
(Locale inLocale) Returns a name for the locale's country that is appropriate for display to the user.final String
Returns a name for the locale's language that is appropriate for display to the user.getDisplayLanguage
(Locale inLocale) Returns a name for the locale's language that is appropriate for display to the user.final String
Returns a name for the locale that is appropriate for display to the user.getDisplayName
(Locale inLocale) Returns a name for the locale that is appropriate for display to the user.Returns a name for the locale's script that is appropriate for display to the user.getDisplayScript
(Locale inLocale) Returns a name for the locale's script that is appropriate for display to the user.final String
Returns a name for the locale's variant code that is appropriate for display to the user.getDisplayVariant
(Locale inLocale) Returns a name for the locale's variant code that is appropriate for display to the user.getExtension
(char key) Returns the extension (or private use) value associated with the specified key, or null if there is no extension associated with the key.Returns the set of extension keys associated with this locale, or the empty set if it has no extensions.Returns a three-letter abbreviation of this locale's country.Returns a three-letter abbreviation of this locale's language.static String[]
Returns a list of all 2-letter country codes defined in ISO 3166.Returns aSet
of ISO3166 country codes for the specified type.static String[]
Returns a list of all 2-letter language codes defined in ISO 639.Returns the language code of this Locale.Returns the script for this locale, which should either be the empty string or an ISO 15924 4-letter script code.Returns the set of unicode locale attributes associated with this locale, or the empty set if it has no attributes.Returns the set of Unicode locale keys defined by this locale, or the empty set if this locale has none.Returns the Unicode locale type associated with the specified Unicode locale key for this locale.Returns the variant code for this locale.boolean
int
hashCode()
Override hashCode.static Locale
lookup
(List<Locale.LanguageRange> priorityList, Collection<Locale> locales) Returns aLocale
instance for the best-matching language tag using the lookup mechanism defined in RFC 4647.static String
lookupTag
(List<Locale.LanguageRange> priorityList, Collection<String> tags) Returns the best-matching language tag using the lookup mechanism defined in RFC 4647.static Locale
Obtains a locale from a language code.static Locale
Obtains a locale from language and country.static Locale
Obtains a locale from language, country and variant.static void
setDefault
(Locale newLocale) Sets the default locale for this instance of the Java Virtual Machine.static void
setDefault
(Locale.Category category, Locale newLocale) Sets the default locale for the specified Category for this instance of the Java Virtual Machine.Returns a copy of thisLocale
with no extensions.Returns a well-formed IETF BCP 47 language tag representing this locale.final String
toString()
Returns a string representation of thisLocale
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
Useful constant for language. -
FRENCH
Useful constant for language. -
GERMAN
Useful constant for language. -
ITALIAN
Useful constant for language. -
JAPANESE
Useful constant for language. -
KOREAN
Useful constant for language. -
CHINESE
Useful constant for language. -
SIMPLIFIED_CHINESE
Useful constant for language. -
TRADITIONAL_CHINESE
Useful constant for language. -
FRANCE
Useful constant for country. -
GERMANY
Useful constant for country. -
ITALY
Useful constant for country. -
JAPAN
Useful constant for country. -
KOREA
Useful constant for country. -
UK
Useful constant for country. -
US
Useful constant for country. -
CANADA
Useful constant for country. -
CANADA_FRENCH
Useful constant for country. -
ROOT
Useful constant for the root locale. The root locale is the locale whose language, country, and variant are empty ("") strings. This is regarded as the base locale of all locales, and is used as the language/country neutral locale for the locale sensitive operations.- Since:
- 1.6
-
CHINA
Useful constant for country. -
PRC
Useful constant for country. -
TAIWAN
Useful constant for country. -
PRIVATE_USE_EXTENSION
public static final char PRIVATE_USE_EXTENSIONThe key for the private use extension ('x').- Since:
- 1.7
- See Also:
-
UNICODE_LOCALE_EXTENSION
public static final char UNICODE_LOCALE_EXTENSIONThe key for Unicode locale extension ('u').- Since:
- 1.7
- See Also:
-
-
Constructor Details
-
Locale
Deprecated.Locale constructors have been deprecated. See Obtaining a Locale for other options.Construct a locale from language, country and variant. This constructor normalizes the language value to lowercase and the country value to uppercase.- 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 theLocale
class description about valid language values.country
- An ISO 3166 alpha-2 country code or a UN M.49 numeric-3 area code. See theLocale
class description about valid country values.variant
- Any arbitrary value used to indicate a variation of aLocale
. See theLocale
class description for the details.- Throws:
NullPointerException
- thrown if any argument is null.
-
Locale
Deprecated.Locale constructors have been deprecated. See Obtaining a Locale for other options.Construct a locale from language and country. This constructor normalizes the language value to lowercase and the country value to uppercase.- 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 theLocale
class description about valid language values.country
- An ISO 3166 alpha-2 country code or a UN M.49 numeric-3 area code. See theLocale
class description about valid country values.- Throws:
NullPointerException
- thrown if either argument is null.
-
Locale
Deprecated.Locale constructors have been deprecated. See Obtaining a Locale for other options.Construct a locale from a language code. This constructor normalizes the language value to lowercase.- 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 theLocale
class description about valid language values.- Throws:
NullPointerException
- thrown if argument is null.- Since:
- 1.4
-
-
Method Details
-
of
Obtains a locale from language, country and variant. This method normalizes the language value to lowercase and the country value to uppercase.- Implementation Note:
- This method does not make any syntactic checks on the input.
Use
Locale.Builder
for 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 theLocale
class description of language values.country
- A country code. See theLocale
class description of country values.variant
- Any arbitrary value used to indicate a variation of aLocale
. See theLocale
class description of variant values.- Returns:
- A
Locale
object - Throws:
NullPointerException
- thrown if any argument is null.- Since:
- 19
-
of
Obtains a locale from language and country. This method normalizes the language value to lowercase and the country value to uppercase.- Implementation Note:
- This method does not make any syntactic checks on the input.
Use
Locale.Builder
for 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 theLocale
class description of language values.country
- A country code. See theLocale
class description of country values.- Returns:
- A
Locale
object - Throws:
NullPointerException
- thrown if either argument is null.- Since:
- 19
-
of
Obtains a locale from a language code. This method normalizes the language value to lowercase.- Implementation Note:
- This method does not make any syntactic checks on the input.
Use
Locale.Builder
for 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 theLocale
class description of language values.- Returns:
- A
Locale
object - Throws:
NullPointerException
- thrown if argument is null.- Since:
- 19
-
getDefault
Gets the current value of the default locale for this instance of the Java Virtual Machine.The Java Virtual Machine sets the default locale during startup based on the host environment. It is used by many locale-sensitive methods if no locale is explicitly specified. It can be changed using the
setDefault
method.- Returns:
- the default locale for this instance of the Java Virtual Machine
-
getDefault
Gets the current value of the default locale for the specified Category for this instance of the Java Virtual Machine.The Java Virtual Machine sets the default locale during startup based on the host environment. It is used by many locale-sensitive methods if no locale is explicitly specified. It can be changed using the setDefault(Locale.Category, Locale) method.
- Parameters:
category
- the specified category to get the default locale- Returns:
- the default locale for the specified Category for this instance of the Java Virtual Machine
- Throws:
NullPointerException
- if category is null- Since:
- 1.7
- See Also:
-
setDefault
Sets the default locale for this instance of the Java Virtual Machine. This does not affect the host locale.If there is a security manager, its
checkPermission
method is called with aPropertyPermission("user.language", "write")
permission before the default locale is changed.The Java Virtual Machine sets the default locale during startup based on the host environment. It is used by many locale-sensitive methods if no locale is explicitly specified.
Since changing the default locale may affect many different areas of functionality, this method should only be used if the caller is prepared to reinitialize locale-sensitive code running within the same Java Virtual Machine.
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:
SecurityException
- if a security manager exists and itscheckPermission
method doesn't allow the operation.NullPointerException
- ifnewLocale
is null- See Also:
-
setDefault
Sets the default locale for the specified Category for this instance of the Java Virtual Machine. This does not affect the host locale.If there is a security manager, its checkPermission method is called with a PropertyPermission("user.language", "write") permission before the default locale is changed.
The Java Virtual Machine sets the default locale during startup based on the host environment. It is used by many locale-sensitive methods if no locale is explicitly specified.
Since changing the default locale may affect many different areas of functionality, this method should only be used if the caller is prepared to reinitialize locale-sensitive code running within the same Java Virtual Machine.
- Parameters:
category
- the specified category to set the default localenewLocale
- the new default locale- Throws:
SecurityException
- if a security manager exists and its checkPermission method doesn't allow the operation.NullPointerException
- if category and/or newLocale is null- Since:
- 1.7
- See Also:
-
getAvailableLocales
Returns an array of installed locales. The returned array represents the union of locales supported by the Java runtime environment and by installedLocaleServiceProvider
implementations. At a minimum, the returned array must contain aLocale
instance equal toLocale.ROOT
and aLocale
instance equal toLocale.US
.- Returns:
- an array of installed locales
-
availableLocales
Returns a stream of installed locales. The returned stream represents the union of locales supported by the Java runtime environment and by installedLocaleServiceProvider
implementations. At a minimum, the returned stream must contain aLocale
instance equal toLocale.ROOT
and aLocale
instance equal toLocale.US
.- Implementation Note:
- Unlike
getAvailableLocales()
, this method does not create a defensive copy of the Locale array. - Returns:
- a stream of installed locales
- Since:
- 21
-
getISOCountries
Returns a list of all 2-letter country codes defined in ISO 3166. Can be used to obtain Locales. This method is equivalent togetISOCountries(Locale.IsoCountryCode type)
withtype
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)
withtype
Locale.IsoCountryCode.PART3
.- Returns:
- An array of ISO 3166 two-letter country codes.
-
getISOCountries
Returns aSet
of ISO3166 country codes for the specified type.- Parameters:
type
-Locale.IsoCountryCode
specified ISO code type.- Returns:
- a
Set
of ISO3166 country codes for the specified type - Throws:
NullPointerException
- if type is null- Since:
- 9
- See Also:
-
getISOLanguages
Returns a list of all 2-letter language codes defined in ISO 639. Can be used to obtain Locales.Note:
- ISO 639 is not a stable standard— some languages' codes have changed. The list this function returns includes both the new and the old codes for the languages whose codes have changed.
- The
Locale
class 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
Returns the language code of this Locale.- 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
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'.- Returns:
- The script code, or the empty string if none is defined.
- Since:
- 1.7
- See Also:
-
getCountry
Returns the country/region code for this locale, which should either be the empty string, an uppercase ISO 3166 2-letter code, or a UN M.49 3-digit code.- Returns:
- The country/region code, or the empty string if none is defined.
- See Also:
-
getVariant
Returns the variant code for this locale.- Returns:
- The variant code, or the empty string if none is defined.
- See Also:
-
hasExtensions
public boolean hasExtensions()- Returns:
true
if thisLocale
has any extensions- Since:
- 1.8
-
stripExtensions
Returns a copy of thisLocale
with no extensions. If thisLocale
has no extensions, thisLocale
is returned.- Returns:
- a copy of this
Locale
with no extensions, orthis
ifthis
has no extensions - Since:
- 1.8
-
getExtension
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[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
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.- Returns:
- The set of extension keys, or the empty set if this locale has no extensions.
- Since:
- 1.7
-
getUnicodeLocaleAttributes
-
getUnicodeLocaleType
Returns the Unicode locale type associated with the specified Unicode locale key for this locale. Returns the empty string for keys that are defined with no type. Returns null if the key is not defined. Keys are case-insensitive. The key must be two alphanumeric characters ([0-9a-zA-Z]), or an IllegalArgumentException is thrown.- 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-formedNullPointerException
- ifkey
is null- Since:
- 1.7
-
getUnicodeLocaleKeys
Returns the set of Unicode locale keys defined by this locale, or the empty set if this locale has none. The returned set is immutable. Keys are all lower case.- Returns:
- The set of Unicode locale keys, or the empty set if this locale has no Unicode locale keywords.
- Since:
- 1.7
-
toString
Returns a string representation of thisLocale
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. Extensions and private use subtags will be in canonical order as explained intoLanguageTag()
.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 (you can't have a locale with just a variant, 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, usetoLanguageTag()
.Examples:
en
de_DE
_GB
en_US_WIN
de__POSIX
zh_CN_#Hans
zh_TW_#Hant_x-java
th_TH_TH_#u-nu-thai
-
toLanguageTag
Returns a well-formed IETF BCP 47 language tag representing this locale.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:
- if all sub-segments match
-
caseFoldLanguageTag
Returns a case folded IETF BCP 47 language tag.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 bylvariant
.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
- iflanguageTag
is not well-formedNullPointerException
- iflanguageTag
isnull
- Since:
- 21
- External Specifications
-
forLanguageTag
Returns a locale for the specified IETF BCP 47 language tag string.If the specified language tag contains any ill-formed subtags, the first such subtag and all following subtags are ignored. Compare to
Locale.Builder.setLanguageTag(java.lang.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"
- When the languageTag argument contains an extlang subtag,
the first such subtag is used as the language, and the primary
language subtag and other extlang subtags are ignored:
Locale.forLanguageTag("ar-aao").getLanguage(); // returns "aao" Locale.forLanguageTag("en-abc-def-us").toString(); // returns "abc_US"
- Case is normalized except for variant tags, which are left unchanged. Language is normalized to lower case, script to title case, country to upper case, and extensions to lower case.
- If, after processing, the locale would exactly match either
ja_JP_JP or th_TH_TH with no extensions, the appropriate
extensions are added as though the constructor had been called:
Locale.forLanguageTag("ja-JP-x-lvariant-JP").toLanguageTag(); // returns "ja-JP-u-ca-japanese-x-lvariant-JP" Locale.forLanguageTag("th-TH-x-lvariant-TH").toLanguageTag(); // returns "th-TH-u-nu-thai-x-lvariant-TH"
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
andforLanguageTag
will round-trip.- Parameters:
languageTag
- the language tag- Returns:
- The locale that best represents the language tag.
- Throws:
NullPointerException
- iflanguageTag
isnull
- Since:
- 1.7
- See Also:
-
getISO3Language
Returns 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.- 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
Returns 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.
- 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
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 defaultDISPLAY
locale. For example, if the locale is fr_FR and the defaultDISPLAY
locale is en_US, getDisplayLanguage() will return "French"; if the locale is en_US and the defaultDISPLAY
locale is fr_FR, getDisplayLanguage() will return "anglais". If the name returned cannot be localized for the defaultDISPLAY
locale, (say, we don't have a Japanese name for Croatian), this function falls back on the English name, and uses the ISO code as a last-resort value. If the locale doesn't specify a language, this function returns the empty string.- Returns:
- The name of the display language.
-
getDisplayLanguage
Returns a name for the locale's language that is appropriate for display to the user. If possible, the name returned will be localized according to inLocale. For example, if the locale is fr_FR and inLocale is en_US, getDisplayLanguage() will return "French"; if the locale is en_US and inLocale is fr_FR, getDisplayLanguage() will return "anglais". If the name returned cannot be localized according to inLocale, (say, we don't have a Japanese name for Croatian), this function falls back on the 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.- 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
- ifinLocale
isnull
-
getDisplayScript
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 defaultDISPLAY
locale. Returns the empty string if this locale doesn't specify a script code.- Returns:
- the display name of the script code for the current default
DISPLAY
locale - Since:
- 1.7
-
getDisplayScript
Returns a name for the locale's script that is appropriate for display to the user. If possible, the name will be localized for the given locale. Returns the empty string if this locale doesn't specify a script code.- Parameters:
inLocale
- The locale for which to retrieve the display script.- Returns:
- the display name of the script code for the current default
DISPLAY
locale - Throws:
NullPointerException
- ifinLocale
isnull
- Since:
- 1.7
-
getDisplayCountry
Returns a name for the locale's country that is appropriate for display to the user. If possible, the name returned will be localized for the defaultDISPLAY
locale. For example, if the locale is fr_FR and the defaultDISPLAY
locale is en_US, getDisplayCountry() will return "France"; if the locale is en_US and the defaultDISPLAY
locale is fr_FR, getDisplayCountry() will return "Etats-Unis". If the name returned cannot be localized for the defaultDISPLAY
locale, (say, we don't have a Japanese name for Croatia), this function falls back on the English name, and uses the ISO code as a last-resort value. If the locale doesn't specify a country, this function returns the empty string.- Returns:
- The name of the country appropriate to the locale.
-
getDisplayCountry
Returns a name for the locale's country that is appropriate for display to the user. If possible, the name returned will be localized 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. (say, we don't have a Japanese name for Croatia), 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.- Parameters:
inLocale
- The locale for which to retrieve the display country.- Returns:
- The name of the country appropriate to the given locale.
- Throws:
NullPointerException
- ifinLocale
isnull
-
getDisplayVariant
Returns a name for the locale's variant code that is appropriate for display to the user. If possible, the name will be localized for the defaultDISPLAY
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
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.- 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
- ifinLocale
isnull
-
getDisplayName
Returns a name for the locale that is appropriate for display to the user. This will be the values returned by getDisplayLanguage(), getDisplayScript(), getDisplayCountry(), getDisplayVariant() and optional 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 (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
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 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 (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
- ifinLocale
isnull
-
clone
-
hashCode
-
equals
Returns true if this Locale is equal to another object. A Locale is deemed equal to another Locale with identical language, script, country, variant and extensions, and unequal to all other objects. -
filter
public static List<Locale> filter(List<Locale.LanguageRange> priorityList, Collection<Locale> locales, Locale.FilteringMode mode) Returns a list of matchingLocale
instances using the filtering mechanism defined in RFC 4647. This filter operation on the givenlocales
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 weightlocales
-Locale
instances used for matchingmode
- filtering mode- Returns:
- a list of
Locale
instances for matching language tags sorted in descending order based on priority or weight, or an empty list if nothing matches. The list is modifiable. - Throws:
NullPointerException
- ifpriorityList
orlocales
isnull
IllegalArgumentException
- if one or more extended language ranges are included in the given list whenLocale.FilteringMode.REJECT_EXTENDED_RANGES
is specified- Since:
- 1.8
-
filter
public static List<Locale> filter(List<Locale.LanguageRange> priorityList, Collection<Locale> locales) Returns a list of matchingLocale
instances using the filtering mechanism defined in RFC 4647. This is equivalent tofilter(List, Collection, FilteringMode)
whenmode
isLocale.FilteringMode.AUTOSELECT_FILTERING
. This filter operation on the givenlocales
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 weightlocales
-Locale
instances used for matching- Returns:
- a list of
Locale
instances for matching language tags sorted in descending order based on priority or weight, or an empty list if nothing matches. The list is modifiable. - Throws:
NullPointerException
- ifpriorityList
orlocales
isnull
- Since:
- 1.8
-
filterTags
public static List<String> filterTags(List<Locale.LanguageRange> priorityList, Collection<String> tags, Locale.FilteringMode mode) Returns a list of matching languages tags using the basic filtering mechanism defined in RFC 4647. This filter operation on the giventags
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 giventags
. Note that if the giventags
is an unorderedCollection
, the returned matching tag out of duplicate tags is subject to change, depending on the implementation of theCollection
.- Parameters:
priorityList
- user's Language Priority List in which each language tag is sorted in descending order based on priority or weighttags
- language tagsmode
- 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
- ifpriorityList
ortags
isnull
IllegalArgumentException
- if one or more extended language ranges are included in the given list whenLocale.FilteringMode.REJECT_EXTENDED_RANGES
is specified- Since:
- 1.8
-
filterTags
public static List<String> filterTags(List<Locale.LanguageRange> priorityList, Collection<String> tags) Returns a list of matching languages tags using the basic filtering mechanism defined in RFC 4647. This is equivalent tofilterTags(List, Collection, FilteringMode)
whenmode
isLocale.FilteringMode.AUTOSELECT_FILTERING
. This filter operation on the giventags
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 giventags
. Note that if the giventags
is an unorderedCollection
, the returned matching tag out of duplicate tags is subject to change, depending on the implementation of theCollection
.- Parameters:
priorityList
- user's Language Priority List in which each language tag is sorted in descending order based on priority or weighttags
- 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
- ifpriorityList
ortags
isnull
- Since:
- 1.8
-
lookup
Returns aLocale
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 weightlocales
-Locale
instances used for matching- Returns:
- the best matching
Locale
instance chosen based on priority or weight, ornull
if nothing matches. - Throws:
NullPointerException
- ifpriorityList
orlocales
isnull
- Since:
- 1.8
-
lookupTag
Returns the best-matching language tag using the lookup mechanism defined in RFC 4647. This lookup operation on the giventags
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 weighttags
- language tags used for matching- Returns:
- the best matching language tag chosen based on priority or
weight, or
null
if nothing matches. - Throws:
NullPointerException
- ifpriorityList
ortags
isnull
- Since:
- 1.8
-