src/java.base/share/classes/sun/util/locale/provider/DateFormatProviderImpl.java

@@ -61,11 +61,11 @@
         return LocaleProviderAdapter.toLocaleArray(langtags);
     }
 
     @Override
     public boolean isSupportedLocale(Locale locale) {
-        return LocaleProviderAdapter.isSupportedLocale(locale, type, langtags);
+        return LocaleProviderAdapter.forType(type).isSupportedProviderLocale(locale, langtags);
     }
 
     /**
      * Returns a new <code>DateFormat</code> instance which formats time
      * with the given formatting style for the specified locale.