Locale.Builder

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, the Builder checks if a value configured by a setter satisfies the syntax requirements defined by the Locale class. A Locale object created by a Builder is well-formed and can be transformed to a well-formed IETF BCP 47 language tag without losing information.

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 a Locale constructor. However, keep in mind that a Locale object created this way might lose the variant information when transformed to a BCP 47 language tag.

The following example shows how to create a Locale object with the Builder.

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

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

Public Constructor Summary

Locale.Builder()
Constructs an empty Builder.

Public Method Summary

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 created 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.

Inherited Method Summary

Public Constructors

public Locale.Builder ()

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

Public Methods

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

public Locale build ()

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

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

Returns
  • A Locale.

public Locale.Builder clear ()

Resets the builder to its initial, empty state.

Returns
  • This builder.

public Locale.Builder clearExtensions ()

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

Returns
  • This builder.

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 comparision for removal is case-insensitive.

Parameters
attribute the attribute
Returns
  • This builder.
Throws
NullPointerException if attribute is null
IllformedLocaleException if attribute is ill-formed

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

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

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(). Grandfathered tags (see forLanguageTag(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

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.

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 created by the Builder is always normalized to upper case.

Parameters
region the region
Returns
  • This builder.
Throws
IllformedLocaleException if region is ill-formed

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

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, 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

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 a Locale constructor.

Parameters
variant the variant
Returns
  • This builder.
Throws
IllformedLocaleException if variant is ill-formed