The JDK and JRE 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.

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 9 and the JRE 9 support all the locales provided by the locale data providers given below.

The locales in Oracle's JDK 9 and the JRE 9 are provided by multiple data sources. They are grouped by their providing sources (hereafter, call it as "locale data provider"). In JDK 9 and the JRE 9, the following five locale data providers are supported.

• CLDR: CLDR locales based on the Unicode Consortium’s CLDR release 29. All the locales provided by the CLDR are supported in Oracle's JDK 9 and the JRE 9, except that BreakIterator and Collator data are not adopted.
• COMPAT: Represents the locale sensitive services that are compatible with the prior JDK releases up to JDK 8 (same as JDK 8's "JRE"). The chart that lists each locale and its numbering system is located here.
• SPI: Represents the locale sensitive services implementing the locale sensitive SPIs in java.text.spi and/or java.util.spi packages.
• 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 9 and the JRE 9, this provider is available on Windows platform and macOS platform.
• JRE: Represents a synonym to "COMPAT". This name is deprecated and will be removed in the future release of JDK.

In Oracle's JDK 9 and the JRE 9, locale data from CLDR locale data provider are used by default, and in some cases where legacy locales are specified in locale sensitive services, such as "JP" variant of "ja_JP" locale, locale data from "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,COMPAT", 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,COMPAT". Specifying the system property with "COMPAT,SPI" will have the same behavior with the prior JDK releases.

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

In Oracle's JDK 9 and the JRE 9, only the US English locale data (and its parent locales, including ROOT locale) are included in java.base module. Other locale data are included in jdk.localedata module. By default, all the locale data are available in the JDK and the JRE images, however, jlink command can strip unnecessary locale data by not specifying them with "--include-locales" plugin option. For example, if the user wants an image that only includes English, Japanese, and any locale in India, 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)

(*) Data for these locales are derived from the Unicode Consortium's Common Locale Data Repository release 1.4.1 on an "AS-IS" basis.

(**) Data for these locales are derived from the Unicode Consortium's Common Locale Data Repository release 1.9 on an "AS-IS" basis.

(***) Data for these locales are derived from the Unicode Consortium's Common Locale Data Repository release 21.0.1 on an "AS-IS" basis.

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 *.

Numbering systems can be specified by a language tag with a numbering system ID, such as th-TH-u-nu-thai. The following are the available numbering system IDs for specifying a numbering system. No algorithmic numbering systems defined in Unicode Locale Data Markup Language (LDML) are supported.

For the Java Foundation Classes (AWT, Swing, 2D, input method framework, drag and drop) and JavaFX, locales can generally be characterized by just the writing system; there are no country or language specific distinctions. Writing system support in the JFC/JavaFX 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/JavaFX if all functionality provided by JFC/JavaFX works adequately for this writing system in the following situations:

• On Windows 7, 8 and 10, when running on a Windows system with UI Language set to a language using that writing system.

• On Solaris and 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 9 and the JRE 9 support 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.

(1) eucJP on Solaris supports the JIS character sets X 0201, X 0208, and X 0212.

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 and the JRE rely entirely on the host operating system. For text composition using input methods, JDK and JRE support native input methods using the host operating system's input method manager as well as input methods developed in the Java programming language (excluding JavaFX environment).

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

On Windows 7, 8 and 10, the JDK and the JRE support use of any keyboard layout or IMM-based input method.

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

Solaris and Linux

The JDK and the JRE support use of any keyboard layout or input method that can be used with a particular Solaris or 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) or JavaFX nodes.

macOS

The JDK and the JRE support 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) or JavaFX nodes.

Applications have two options for selecting fonts:

• Using the logical font names Serif, SansSerif, Dialog, DialogInput, Monospaced.
• Using 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 JavaFX

No precise list of supported font rendering locales can be provided since support is largely dependent on the installed platform fonts, and the complex text rendering capabilities of the native platform. However in general this means the capabilities of JavaFX should be similar to those of the platform itself, and for the supported modern desktop platforms this should match or exceed those of the equivalent JFC/Swing text rendering.

The automatic implicit addition of fallback fonts to all FX fonts other than application embedded fonts means that the application should benefit from the broadest locale support no matter which FX font is in use.

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 JRE work to the same extent as text rendering on the screen.

On Windows 7, 8, and 10, text using the entire Unicode character set can be transferred between applications.

On Solaris and 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.

The user interface elements provided by the JRE 9, include Swing dialogs, messages written by the runtime environment to the standard output and standard error streams, as well as messages produced by the tools provided with the JRE. These languages are also supported in JavaFX. These user interface elements are localized into the following languages:

The user interface elements provided by the JDK 9, include messages produced by the tools that are only part of the JDK in addition to the elements provided by the JRE. These languages are also supported in JavaFX. The additional user interface elements are localized into the following languages: