Locale.FilteringMode (Java SE 21 & JDK 21)
Description: declaration: module: java.base, package: java.util, class: Locale, enum: FilteringMode
Keywords: java.util.Locale.FilteringMode class

Module java.base
Package java.util

# Enum Class Locale.FilteringMode

java.lang.Object
java.lang.Enum<Locale.FilteringMode>
java.util.Locale.FilteringMode

All Implemented Interfaces:
  `Serializable`, `Comparable<Locale.FilteringMode>`, `Constable`

Enclosing class:
  `Locale`

public static enum Locale.FilteringMode extends Enum<Locale.FilteringMode>
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:

        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:

Filtering method behavior
Filtering Mode | Language Priority List: `"de-DE"` | Language Priority List: `"de-*-DE"`
--- | --- | ---
`AUTOSELECT_FILTERING` | Performs basic filtering and returns `"de-DE"` and `"de-DE-1996"`. | Performs extended filtering and returns `"de-DE"`, `"de-Deva-DE"`, `"de-DE-1996"`, `"de-Latn-DE"`, and `"de-Latn-DE-1996"`.
`EXTENDED_FILTERING` | Performs extended filtering and returns `"de-DE"`, `"de-Deva-DE"`, `"de-DE-1996"`, `"de-Latn-DE"`, and `"de-Latn-DE-1996"`. | Same as above.
`IGNORE_EXTENDED_RANGES` | Performs basic filtering and returns `"de-DE"` and `"de-DE-1996"`. | Performs basic filtering and returns `null` because nothing matches.
`MAP_EXTENDED_RANGES` | Same as above. | Performs basic filtering and returns `"de-DE"` and `"de-DE-1996"` because `"de-*-DE"` is mapped to `"de-DE"`.
`REJECT_EXTENDED_RANGES` | Same as above. | Throws `IllegalArgumentException` because `"de-*-DE"` is not a valid basic language range.

Since:
  1.8
External Specifications
  - RFC 4647: Matching of Language Tags
See Also:
  - `Locale.filter(List, Collection, FilteringMode)`
  - `Locale.filterTags(List, Collection, FilteringMode)`

- ## Nested Class Summary

  ## Nested classes/interfaces declared in class java.lang.Enum

  `Enum.EnumDesc<E extends Enum<E>>`

- ## Enum Constant Summary

  Enum Constants
  Enum Constant
  Description
  `AUTOSELECT_FILTERING`
  Specifies automatic filtering mode based on the given Language Priority List consisting of language ranges.
  `EXTENDED_FILTERING`
  Specifies extended filtering.
  `IGNORE_EXTENDED_RANGES`
  Specifies basic filtering: Note that any extended language ranges included in the given Language Priority List are ignored.
  `MAP_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.
  `REJECT_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 `IllegalArgumentException`.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `static Locale.FilteringMode`
  `valueOf(String name)`
  Returns the enum constant of this class with the specified name.
  `static Locale.FilteringMode[]`
  `values()`
  Returns an array containing the constants of this enum class, in the order they are declared.

  ### Methods declared in class java.lang.Enum

  `clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf`

  ### Methods declared in class java.lang.Object

  `getClass, notify, notifyAll, wait, wait, wait`

- ## Enum Constant Details

  - ### AUTOSELECT_FILTERING

    public static final Locale.FilteringMode AUTOSELECT_FILTERING
    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.

  - ### EXTENDED_FILTERING

    public static final Locale.FilteringMode EXTENDED_FILTERING
    Specifies extended filtering.

  - ### IGNORE_EXTENDED_RANGES

    public static final Locale.FilteringMode IGNORE_EXTENDED_RANGES
    Specifies basic filtering: Note that any extended language ranges included in the given Language Priority List are ignored.

  - ### MAP_EXTENDED_RANGES

    public static final Locale.FilteringMode MAP_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 `"*"` is treated as a language range `"*"`. For example, `"*-US"` is treated as `"*"`. If `"*"` is not the first subtag, `"*"` and extra `"-"` are removed. For example, `"ja-*-JP"` is mapped to `"ja-JP"`.

  - ### REJECT_EXTENDED_RANGES

    public static final Locale.FilteringMode REJECT_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 `IllegalArgumentException`.

- ## Method Details

  - ### values

    public static Locale.FilteringMode[] values()
    Returns an array containing the constants of this enum class, in the order they are declared.
    Returns:
      an array containing the constants of this enum class, in the order they are declared

  - ### valueOf

    public static Locale.FilteringMode valueOf(String name)
    Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)
    Parameters:
      `name` - the name of the enum constant to be returned.
    Returns:
      the enum constant with the specified name
    Throws:
      `IllegalArgumentException` - if this enum class has no constant with the specified name
      `NullPointerException` - if the argument is null