src/java.base/share/classes/sun/util/cldr/CLDRLocaleProviderAdapter.java

*** 1,7 ****
  /*
!  * Copyright (c) 2012, 2017, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 61,72 ****
--- 61,78 ----
      // Assumption: CLDR has only one non-Base module.
      private final LocaleDataMetaInfo nonBaseMetaInfo;
  
      // parent locales map
      private static volatile Map<Locale, Locale> parentLocalesMap;
+     // language aliases map
+     private static volatile Map<String,String> langAliasesMap;
+     // cache to hold  locale to locale mapping for language aliases.
+     private static final Map<Locale, Locale> langAliasesCache;
      static {
          parentLocalesMap = new ConcurrentHashMap<>();
+         langAliasesMap = new ConcurrentHashMap<>();
+         langAliasesCache = new ConcurrentHashMap<>();
          // Assuming these locales do NOT have irregular parent locales.
          parentLocalesMap.put(Locale.ROOT, Locale.ROOT);
          parentLocalesMap.put(Locale.ENGLISH, Locale.ENGLISH);
          parentLocalesMap.put(Locale.US, Locale.US);
      }
*** 139,148 ****
--- 145,170 ----
              locs[index++] = Locale.forLanguageTag(tag);
          }
          return locs;
      }
      
+     private Locale applyAliases(Locale loc) {
+         if (langAliasesMap.isEmpty()) {
+             langAliasesMap = baseMetaInfo.getLanguageAliasMap();
+         }
+         Locale locale = langAliasesCache.get(loc);
+         if (locale == null) {
+             String locTag = loc.toLanguageTag();
+             Locale aliasLocale = langAliasesMap.containsKey(locTag)
+                     ? Locale.forLanguageTag(langAliasesMap.get(locTag)) : loc;
+             langAliasesCache.putIfAbsent(loc, aliasLocale);
+             return aliasLocale;
+         } else {
+             return locale;
+         }
+     }
+ 
      @Override
      protected Set<String> createLanguageTagSet(String category) {
          // Assume all categories support the same set as AvailableLocales
          // in CLDR adapter.
          category = "AvailableLocales";
*** 173,183 ****
      }
  
      // Implementation of ResourceBundleBasedAdapter
      @Override
      public List<Locale> getCandidateLocales(String baseName, Locale locale) {
!         List<Locale> candidates = super.getCandidateLocales(baseName, locale);
          return applyParentLocales(baseName, candidates);
      }
  
      private List<Locale> applyParentLocales(String baseName, List<Locale> candidates) {
          // check irregular parents
--- 195,205 ----
      }
  
      // Implementation of ResourceBundleBasedAdapter
      @Override
      public List<Locale> getCandidateLocales(String baseName, Locale locale) {
!         List<Locale> candidates = super.getCandidateLocales(baseName, applyAliases(locale));
          return applyParentLocales(baseName, candidates);
      }
  
      private List<Locale> applyParentLocales(String baseName, List<Locale> candidates) {
          // check irregular parents