JDK 23 Supported Locales

• Installer and Supported Languages
• Enabled Locales for java.util and java.text Functionality
  • Supported Locales Via Locale Data Providers
  • Configuration Of Locale Data Providers
  • Supported Unicode Language-Tag extensions
  • Locales and Modules
  • Locales Supported By CLDR provider
  • Historical Locales
• Enabled Writing Systems for Java Foundation Classes
  • Overview
  • Text Input
  • Text Rendering
  • Drag and Drop
• User Interface Translation

Installer and Supported Languages

The JDK Installers are localized to the languages specified in the User Interface Translation table. The installers will use the system's default locale setting to determine which of the supported languages to use at the time of installation. If the system's default locale is not supported by the installers, the installers will be displayed in English.

Enabled Locales for java.util and java.text Functionality

The support for locale-sensitive behavior in the java.util and java.text packages is almost entirely platform independent, so all locales are supported in the same way and simultaneously, independent of the host operating system and its localization. The only platform dependent functionality is the setting of the initial default locale and the initial default time zone based on the host operating system's locale and time zone.

Oracle's JDK 23 supports all the locales provided by the locale data providers given below.

Supported Locales via Locale Data Providers

The locales in Oracle's JDK 23 are provided by multiple data sources. They are grouped by their providing sources (hereafter, call it as "locale data provider"). In JDK 23, the following three locale data providers are supported.

• CLDR: CLDR locales based on the Unicode Consortium’s CLDR release 45. All the locales provided by the CLDR are supported in Oracle's JDK 23, except that BreakIterator and Collator data are not adopted.
• HOST: A provider that reflects the user's custom settings in the underlying operating system. This provider enables the default locale(s) (Locale.Category.FORMAT and/or Locale.Category.DISPLAY) utilizing the underlying operating system. In Oracle's JDK 23, this provider is available on Windows platform and macOS platform.
• SPI: Represents the locale sensitive services implementing the locale sensitive SPIs in java.text.spi and/or java.util.spi packages.

Note that the legacy locale data provided by "COMPAT"/"JRE" locale providers in prior releases are now removed. Refer to JEP 252: Use CLDR Locale Data by Default, including how to migrate to CLDR, for more detail.

Configuration of Locale Data Providers

In Oracle's JDK 23, locale data from CLDR locale data provider are used by default. In some cases where legacy locales are specified in locale sensitive services, such as "JP" variant of "ja_JP" locale, the legacy locale data, previously provided by "COMPAT" provider is used. Locales from other locale providers can be used by configuring the “java.locale.providers” system property. For example, if the user wants to have the same experience with the underlying operating system, specifying the system property with "HOST,CLDR", lets the locale sensitive services behave like what the underlying OS does for the default locale. The default behavior is equivalent to specifying the system property with "CLDR".

Refer to java.util.spi.LocaleServiceProvider class’ class description for more detail.

Supported Unicode Language-Tag extensions

Unicode Consortium's LDML specification defines Unicode locale extensions. These are the supported extensions in Oracle's JDK 23:

• cu (currency type)
• fw (first day of week)
• rg (region override)
• tz (time zone)
• co (collator; only for Swedish Traditional sorting (trad))

These Unicode extensions affect the behavior of the relevant library functions, such as classes in java.text, java.time, and java.util packages. For more detail, refer to JEP 314: Additional Unicode Language-Tag Extensions (except collation).

Locales and Modules

In Oracle's JDK 23, only the US English locale data (and its parent locales, including the ROOT locale) are included in the java.base module. Other locale data are included in the jdk.localedata module. By default, all locale data is available in the JDK. Developers can create a smaller run-time image by stripping unneeded locale data by using the jlink command with the “--include-locales” option. For example, if a user wants to limit locale data to English, Japanese, and all Indian locales, the following jlink command option will create the image:

jlink --add-modules java.base,jdk.localedata --include-locales en,ja,*-IN (other required jlink options are omitted here)

The locales supported by the CLDR provider

The CLDR provider utilizes the locale data provided by the corresponding CLDR version. For JDK 23, CLDR version 45 data are used. The JDK supports the locales from their "basic" or above coverage levels. For more detail, refer to their release note.

The hisitorically supported JDK locales are as follows.

Implicit default scripts are in parentheses. They are not returned from the Locale.getScript() method.

Locales can be constructed with Locale.forLanguageTag(<Language Tag>) or Locale(<Language>, <Country>[, <Variant>]) where <Language Tag> is the Language Tag column value, <Language> is the ISO 639 value, <Country> is the ISO 3166 value, and <Variant> is the Variant column value if it’s neither empty nor *.

Locales can be constructed only with Locale.forLanguageTag(<Language Tag>) if the Variant column value is *.

Enabled Writing Systems for Java Foundation Classes

Overview

For the Java Foundation Classes ("JFC" hereafter, including AWT, Swing, 2D, input method framework, drag and drop) locales can generally be characterized by just the writing system; there are no country or language specific distinctions. Writing system support in the JFC depends to some extent on the host operating system, and full support for simultaneous use of multiple languages is not always possible.

We consider a writing system supported by JFC if all functionality provided by JFC works adequately for this writing system in the following situations:

• On Windows, when running with UI Language set to a language using that writing system.

• On Linux, when running on a host operating system with the locale set to one using that writing system and one of the encodings shown for that writing system in the table below.

• On macOS, when running with the Language set to one using that writing system and one of the encodings shown for that writing system in the table below.

Oracle's JDK 23 supports all writing systems shown below. Peered AWT components are only supported for a subset of the writing systems - see the last column.

Details on various areas of functionality are provided in the sections below.

Supported Writing Systems

Text Input

Support for text input consists of two parts: interpretation of keyboard layouts, and text composition using input methods. For interpretation of keyboard layouts, the JDK relies entirely on the host operating system. For text composition using input methods, JDK supports native input methods using the host operating system's input method manager as well as input methods developed in the Java programming language.

Locale support in input methods implemented in the Java programming language depends solely on the set of installed input methods, not on the host operating system and its localization. However, support for the use of input methods implemented in the Java programming language with peered components is implementation dependent - see below.

Support for keyboard layouts and and native input methods varies between platforms.

Windows

The JDK supports use of any keyboard layout or IMM-based input method.

Input methods implemented in the Java programming language are supported in all components, on all versions of Windows.

Linux

The JDK supports use of any keyboard layout or input method that can be used with a particular Linux locale.

Input methods implemented in the Java programming language are supported in lightweight components (such as Swing text components), but not in peered components (such as AWT text components).

macOS

The JDK supports use of any input source.

Input methods implemented in the Java programming language are supported in lightweight components (such as Swing text components), but not in peered components (such as AWT text components).

Text Rendering

Applications have two options for selecting fonts:

• The logical font names Serif, SansSerif, Dialog, DialogInput, Monospaced.
• A physical font, requesting it by name.

Text Rendering in Lightweight Components

When using logical font names, text in at least the writing system of the host locale and the Western European subset of the Latin writing system is supported.

When using physical fonts, we need to distinguish between simple and complex writing systems. Simple writing systems have a one-to-one mapping from characters to glyphs, and glyphs are placed on the baseline continuously from left to right. Complex writing systems may use different glyphs for the same character based on context, may form ligatures, may be written from right to left, and may reorder glyphs during line layout, or may have other rules for placing glyphs (in particular for combining marks).

The 2D text rendering system supports any combination of simple writing systems and the complex writing systems listed in the table above. Within these limitations, the range of supported writing systems is determined by the font. A single TrueType font might provide glyphs covering the entire Unicode character set and a Unicode based character-to-glyph mapping. Given such a font, 2D can support all simple writing systems as well as the complex writing systems shown in the table above. Other complex writing systems are not supported.

Text Rendering in Peered Components

When using logical font names, text in at least the writing system of the host operating system's locale is supported.

Physical fonts are not supported in peered components.

Text Rendering in Printing

There are three printing APIs:

• The 2D printing API, using the java.awt.print.PrinterJob.getPrinterJob method.
• The AWT printing API, using the java.awt.Toolkit.getPrintJob method.
• The pluggable services printing API, using the javax.print package.

Text rendering using the AWT and 2D printing API works to the same extent as text rendering on the screen. Text rendering using the pluggable services printing API depends on the printing service used; the services provided by the JDK work to the same extent as text rendering on the screen.

Drag and Drop

On Windows, text using the entire Unicode character set can be transferred between applications.

On Linux, text in the character encoding of the host operating system's locale can be transferred between applications.

Applications that need to transfer arbitrary text independent of the host operating system, can do so using serialization: Create a Transferable which supports only one flavor: DataFlavor.stringFlavor. This flavor represents the serialized representation of a String. Make sure that the target supports stringFlavor as well. When the transfer occurs, the AWT will serialize out the String on one end and deserialize on the other. This is much slower than a native platform text transfer, but it will succeed where native transfers may not.

User Interface Translation

 The user interface elements provided by JDK 23, include messages produced by the tools that are only part of the JDK. The user interface elements are localized into the following languages: