Module java.base

Package java.util

Class Locale.Builder

java.lang.Object

java.util.Locale.Builder

Enclosing class:

Locale

public static final class Locale.Builder
extends Object

Builder is used to build instances of Locale from values configured by the setters. Unlike the Locale constructors or Locale.of() factory methods, the Builder checks if a value configured by a setter satisfies the syntax requirements defined by the Locale class. A Locale object obtained from a Builder is well-formed and can be transformed to a well-formed IETF BCP 47 language tag without losing information.

Implementation Note:

The Locale class does not provide any syntactic restrictions on variant, while BCP 47 requires each variant subtag to be 5 to 8 alphanumerics or a single numeric followed by 3 alphanumerics. The method setVariant throws IllformedLocaleException for a variant that does not satisfy this restriction. If it is necessary to support such a variant, use Locale.of(String, String, String). However, keep in mind that a Locale object obtained this way might lose the variant information when transformed to a BCP 47 language tag.

The following example shows how to obtain a Locale object using a Builder.

Locale aLocale = new Locale.Builder().setLanguage("sr").setScript("Latn").setRegion("RS").build();

Builders can be reused; clear() resets all fields to their default values.

Since:

1.7

See Also:

• Locale.forLanguageTag(java.lang.String)
• Locale.of(String, String, String)

Constructor Summary

Constructors

Constructor	Description
Builder()	Constructs an empty Builder.

Method Summary

Modifier and Type	Method	Description
Locale.Builder	addUnicodeLocaleAttribute(String attribute)	Adds a unicode locale attribute, if not already present, otherwise has no effect.
Locale	build()	Returns an instance of Locale obtained from the fields set on this builder.
Locale.Builder	clear()	Resets the builder to its initial, empty state.
Locale.Builder	clearExtensions()	Resets the extensions to their initial, empty state.
Locale.Builder	removeUnicodeLocaleAttribute(String attribute)	Removes a unicode locale attribute, if present, otherwise has no effect.
Locale.Builder	setExtension(char key, String value)	Sets the extension for the given key.
Locale.Builder	setLanguage(String language)	Sets the language.
Locale.Builder	setLanguageTag(String languageTag)	Resets the Builder to match the provided IETF BCP 47 language tag.
Locale.Builder	setLocale(Locale locale)	Resets the Builder to match the provided locale.
Locale.Builder	setRegion(String region)	Sets the region.
Locale.Builder	setScript(String script)	Sets the script.
Locale.Builder	setUnicodeLocaleKeyword(String key, String type)	Sets the Unicode locale keyword type for the given key.
Locale.Builder	setVariant(String variant)	Sets the variant.

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Builder

public Builder()

Constructs an empty Builder. The default value of all fields, extensions, and private use information is the empty string.

Method Details

setLocale

public Locale.Builder setLocale(Locale locale)

Resets the Builder to match the provided locale. Existing state is discarded.

All fields of the locale must be well-formed, see Locale.

Locales with any ill-formed fields cause IllformedLocaleException to be thrown, except for the following three cases which are accepted for compatibility reasons:

• Locale("ja", "JP", "JP") is treated as "ja-JP-u-ca-japanese"
• Locale("th", "TH", "TH") is treated as "th-TH-u-nu-thai"
• Locale("no", "NO", "NY") is treated as "nn-NO"

Parameters:

locale - the locale

Returns:

This builder.

Throws:

IllformedLocaleException - if locale has any ill-formed fields.

NullPointerException - if locale is null.

setLanguageTag

public Locale.Builder setLanguageTag(String languageTag)

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 clear(). Legacy tags (see Locale.forLanguageTag(java.lang.String)) are converted to their canonical form before being processed. Otherwise, the language tag must be well-formed (see Locale) or an exception is thrown (unlike Locale.forLanguageTag, which just discards ill-formed and following portions of the tag).

Parameters:

languageTag - the language tag

Returns:

This builder.

Throws:

IllformedLocaleException - if languageTag is ill-formed

See Also:

• Locale.forLanguageTag(String)

setLanguage

public Locale.Builder setLanguage(String language)

Sets the language. If language is the empty string or null, the language in this Builder is removed. Otherwise, the language must be well-formed or an exception is thrown.

The typical language value is a two or three-letter language code as defined in ISO639.

Parameters:

language - the language

Returns:

This builder.

Throws:

IllformedLocaleException - if language is ill-formed

setScript

public Locale.Builder setScript(String script)

Sets the script. If script is null or the empty string, the script in this Builder is removed. Otherwise, the script must be well-formed or an exception is thrown.

The typical script value is a four-letter script code as defined by ISO 15924.

Parameters:

script - the script

Returns:

This builder.

Throws:

IllformedLocaleException - if script is ill-formed

setRegion

public Locale.Builder setRegion(String region)

Sets the region. If region is null or the empty string, the region in this Builder is removed. Otherwise, the region must be 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 Locale obtained from a Builder is always normalized to upper case.

Parameters:

region - the region

Returns:

This builder.

Throws:

IllformedLocaleException - if region is ill-formed

setVariant

public Locale.Builder setVariant(String variant)

Sets the variant. If variant is null or the empty string, the variant in this Builder is removed. Otherwise, it must consist of one or more well-formed subtags, or an exception is thrown.

Note: This method checks if variant satisfies the IETF BCP 47 variant subtag's syntax requirements, and normalizes the value to lowercase letters. However, the Locale class does not impose any syntactic restriction on variant, and the variant value in Locale is case sensitive. To set such a variant, use Locale.of(String, String, String).

Parameters:

variant - the variant

Returns:

This builder.

Throws:

IllformedLocaleException - if variant is ill-formed

See Also:

• Locale.of(String, String, String)

setExtension

public Locale.Builder setExtension(char key,
 String value)

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 well-formed or an exception is thrown.

Note: The key 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 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.

Parameters:

key - the extension key

value - the extension value

Returns:

This builder.

Throws:

IllformedLocaleException - if key is illegal or value is ill-formed

See Also:

• setUnicodeLocaleKeyword(String, String)

setUnicodeLocaleKeyword

public Locale.Builder setUnicodeLocaleKeyword(String key,
 String type)

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 well-formed or an exception is thrown.

Keys and types are converted to lower case.

Note:Setting the 'u' extension via setExtension(char, java.lang.String) replaces all Unicode locale keywords with those defined in the extension.

Parameters:

key - the Unicode locale key

type - the Unicode locale type

Returns:

This builder.

Throws:

IllformedLocaleException - if key or type is ill-formed

NullPointerException - if key is null

See Also:

• setExtension(char, String)

addUnicodeLocaleAttribute

public Locale.Builder addUnicodeLocaleAttribute(String attribute)

Adds a unicode locale attribute, if not already present, otherwise has no effect. The attribute must not be null and must be well-formed or an exception is thrown.

Parameters:

attribute - the attribute

Returns:

This builder.

Throws:

NullPointerException - if attribute is null

IllformedLocaleException - if attribute is ill-formed

See Also:

• setExtension(char, String)

removeUnicodeLocaleAttribute

public Locale.Builder removeUnicodeLocaleAttribute(String attribute)

Removes a unicode locale attribute, if present, otherwise has no effect. The attribute must not be null and must be well-formed or an exception is thrown.

Attribute comparison for removal is case-insensitive.

Parameters:

attribute - the attribute

Returns:

This builder.

Throws:

NullPointerException - if attribute is null

IllformedLocaleException - if attribute is ill-formed

See Also:

• setExtension(char, String)

clear

public Locale.Builder clear()

Resets the builder to its initial, empty state.

Returns:

This builder.

clearExtensions

public Locale.Builder clearExtensions()

Resets the extensions to their initial, empty state. Language, script, region and variant are unchanged.

Returns:

This builder.

See Also:

• setExtension(char, String)

build

public Locale build()

Returns an instance of Locale obtained from the fields set on this builder.

This applies the conversions listed in Locale.forLanguageTag(java.lang.String) when constructing a Locale. (Legacy tags are handled in setLanguageTag(java.lang.String).)

Returns:

A Locale.