Class LocaleUtils
Locale
.
This class tries to handle null
input gracefully.
An exception will not be thrown for a null
input.
Each method documents its behavior in more detail.
- Since:
- 2.2
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Nested Class Summary
Nested Classes -
Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final ConcurrentMap
<String, List<Locale>> Concurrent map of country locales by language.private static final ConcurrentMap
<String, List<Locale>> Concurrent map of language locales by country.private static final char
The dash character'
'-''
.private static final char
The underscore character'
'_''
.private static final String
The undetermined language "und". -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionObtains an unmodifiable list of installed locales.availableLocaleList
(Predicate<Locale> predicate) Obtains an unmodifiable set of installed locales.countriesByLanguage
(String languageCode) Obtains the list of countries supported for a given language.static boolean
isAvailableLocale
(Locale locale) Checks if the locale specified is in the set of available locales.private static boolean
Checks whether the given String is a ISO 3166 alpha-2 country code.private static boolean
Checks whether the given String is a ISO 639 compliant language code.static boolean
isLanguageUndetermined
(Locale locale) Tests whether a Locale's language is undetermined.private static boolean
isNumericAreaCode
(String str) Checks whether the given String is a UN M.49 numeric area code.languagesByCountry
(String countryCode) Obtains the list of languages supported for a given country.localeLookupList
(Locale locale) Obtains the list of locales to search through when performing a locale search.localeLookupList
(Locale locale, Locale defaultLocale) Obtains the list of locales to search through when performing a locale search.private static Locale
parseLocale
(String str) Tries to parse a Locale from the given String.static Locale
Converts a String to a Locale.static Locale
Returns the given locale if non-null
, otherwiseLocale.getDefault()
.
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Field Details
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UNDERSCORE
private static final char UNDERSCOREThe underscore character'
'_''
.- See Also:
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UNDETERMINED
The undetermined language "und".- See Also:
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DASH
private static final char DASHThe dash character'
'-''
.- See Also:
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cLanguagesByCountry
Concurrent map of language locales by country. -
cCountriesByLanguage
Concurrent map of country locales by language.
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Constructor Details
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LocaleUtils
Deprecated.TODO Make private in 4.0.LocaleUtils
instances should NOT be constructed in standard programming. Instead, the class should be used asLocaleUtils.toLocale("en_GB");
.This constructor is public to permit tools that require a JavaBean instance to operate.
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Method Details
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availableLocaleList
Obtains an unmodifiable list of installed locales.This method is a wrapper around
Locale.getAvailableLocales()
. It is more efficient, as the JDK method must create a new array each time it is called.- Returns:
- the unmodifiable list of available locales
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availableLocaleList
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availableLocaleSet
Obtains an unmodifiable set of installed locales.This method is a wrapper around
Locale.getAvailableLocales()
. It is more efficient, as the JDK method must create a new array each time it is called.- Returns:
- the unmodifiable set of available locales
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countriesByLanguage
Obtains the list of countries supported for a given language.This method takes a language code and searches to find the countries available for that language. Variant locales are removed.
- Parameters:
languageCode
- the 2 letter language code, null returns empty- Returns:
- an unmodifiable List of Locale objects, not null
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isAvailableLocale
Checks if the locale specified is in the set of available locales.- Parameters:
locale
- the Locale object to check if it is available- Returns:
- true if the locale is a known locale
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isISO3166CountryCode
Checks whether the given String is a ISO 3166 alpha-2 country code.- Parameters:
str
- the String to check- Returns:
- true, is the given String is a ISO 3166 compliant country code.
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isISO639LanguageCode
Checks whether the given String is a ISO 639 compliant language code.- Parameters:
str
- the String to check.- Returns:
- true, if the given String is a ISO 639 compliant language code.
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isLanguageUndetermined
Tests whether a Locale's language is undetermined.A Locale's language tag is undetermined if it's value is
"und"
. If a language is empty, or not well-formed (for example, "a" or"e2"), it will be equal to"und"
.- Parameters:
locale
- the locale to test.- Returns:
- whether a Locale's language is undetermined.
- Since:
- 3.14.0
- See Also:
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isNumericAreaCode
Checks whether the given String is a UN M.49 numeric area code.- Parameters:
str
- the String to check- Returns:
- true, is the given String is a UN M.49 numeric area code.
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languagesByCountry
Obtains the list of languages supported for a given country.This method takes a country code and searches to find the languages available for that country. Variant locales are removed.
- Parameters:
countryCode
- the 2-letter country code, null returns empty- Returns:
- an unmodifiable List of Locale objects, not null
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localeLookupList
Obtains the list of locales to search through when performing a locale search.localeLookupList(Locale("fr", "CA", "xxx")) = [Locale("fr", "CA", "xxx"), Locale("fr", "CA"), Locale("fr")]
- Parameters:
locale
- the locale to start from- Returns:
- the unmodifiable list of Locale objects, 0 being locale, not null
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localeLookupList
Obtains the list of locales to search through when performing a locale search.localeLookupList(Locale("fr", "CA", "xxx"), Locale("en")) = [Locale("fr", "CA", "xxx"), Locale("fr", "CA"), Locale("fr"), Locale("en"]
The result list begins with the most specific locale, then the next more general and so on, finishing with the default locale. The list will never contain the same locale twice.
- Parameters:
locale
- the locale to start from, null returns empty listdefaultLocale
- the default locale to use if no other is found- Returns:
- the unmodifiable list of Locale objects, 0 being locale, not null
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parseLocale
Tries to parse a Locale from the given String.See for the format.
- Parameters:
str
- the String to parse as a Locale.- Returns:
- a Locale parsed from the given String.
- Throws:
IllegalArgumentException
- if the given String can not be parsed.- See Also:
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toLocale
Returns the given locale if non-null
, otherwiseLocale.getDefault()
.- Parameters:
locale
- a locale ornull
.- Returns:
- the given locale if non-
null
, otherwiseLocale.getDefault()
. - Since:
- 3.12.0
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toLocale
Converts a String to a Locale.This method takes the string format of a locale and creates the locale object from it.
LocaleUtils.toLocale("") = new Locale("", "") LocaleUtils.toLocale("en") = new Locale("en", "") LocaleUtils.toLocale("en_GB") = new Locale("en", "GB") LocaleUtils.toLocale("en-GB") = new Locale("en", "GB") LocaleUtils.toLocale("en_001") = new Locale("en", "001") LocaleUtils.toLocale("en_GB_xxx") = new Locale("en", "GB", "xxx") (#)
(#) The behavior of the JDK variant constructor changed between JDK1.3 and JDK1.4. In JDK1.3, the constructor upper cases the variant, in JDK1.4, it doesn't. Thus, the result from getVariant() may vary depending on your JDK.
This method validates the input strictly. The language code must be lowercase. The country code must be uppercase. The separator must be an underscore or a dash. The length must be correct.
- Parameters:
str
- the locale String to convert, null returns null- Returns:
- a Locale, null if null input
- Throws:
IllegalArgumentException
- if the string is an invalid format- See Also:
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