On Wed, 29 Apr 2026 18:38:50 GMT, Justin Lu <[email protected]> wrote:
>> Enabling customization of localized format patterns for the `java.time` >> date/time formatters through the locale-sensitive SPI. While existing SPIs >> allow customization of textual elements, such as month-of-year names, >> formatting patterns (e.g., "dd/MM/yyyy") cannot currently be customized for >> a given locale. >> >> This enhancement is needed to support customers migrating from the >> now-removed COMPAT locale resources to CLDR-based ones. >> >> --------- >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > src/java.base/macosx/classes/sun/util/locale/provider/HostLocaleProviderAdapterImpl.java > line 176: > >> 174: public String getDateTimeFormatterPattern(String >> requestedTemplate, String calType, Locale locale) { >> 175: // Not supported. Return the requestedTemplate as is. >> 176: return requestedTemplate; > > I think this introduces a behavioral change and is not ideal behavior. > Before, the default implementation threw `DateTimeException` for these > methods. However, in the new HOST code we are returning the pattern as is. > Thus, users who invoke methods that delegate to this code will silently > succeed with non-supported patterns. For example, with a HOST only provider, code that called `DateTimeFormatterBuilder.getLocalizedDateTimePattern` will now silently return the pattern as is, instead of failing with the expected `DateTimeException`. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/30979#discussion_r3163373877
