@Nullable private static List<Locale> extractLocalesFromString(final String rawLocales) { if (rawLocales.isEmpty()) { return Collections.emptyList(); } final String[] splitRawLocales = rawLocales.split(","); final List<Locale> locales = new ArrayList<>(splitRawLocales.length); for (String rawLocale : splitRawLocales) { final Locale locale = PropertiesUtil.getLocale("_" + rawLocale + ".properties"); if (locale == PropertiesUtil.DEFAULT_LOCALE) { return null; } else if (!locales.contains(locale)) { locales.add(locale); } } return locales; }