src/java.base/share/classes/java/util/LocaleISOData.java

*** 1,7 ****
  /*
!  * Copyright (c) 2005, 2013, 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) 2005, 2016, 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
*** 23,32 ****
--- 23,34 ----
   * questions.
   */
  
  package java.util;
  
+ import java.util.Locale.IsoCountryCode;
+ 
  class LocaleISOData {
      /**
       * The 2- and 3-letter ISO 639 language codes.
       */
      static final String isoLanguageTable =
*** 229,239 ****
          + "AF" + "AFG"  // Afghanistan
          + "AG" + "ATG"  // Antigua and Barbuda
          + "AI" + "AIA"  // Anguilla
          + "AL" + "ALB"  // Albania, People's Socialist Republic of
          + "AM" + "ARM"  // Armenia
!         + "AN" + "ANT"  // Netherlands Antilles
          + "AO" + "AGO"  // Angola, Republic of
          + "AQ" + "ATA"  // Antarctica (the territory South of 60 deg S)
          + "AR" + "ARG"  // Argentina, Argentine Republic
          + "AS" + "ASM"  // American Samoa
          + "AT" + "AUT"  // Austria, Republic of
--- 231,241 ----
          + "AF" + "AFG"  // Afghanistan
          + "AG" + "ATG"  // Antigua and Barbuda
          + "AI" + "AIA"  // Anguilla
          + "AL" + "ALB"  // Albania, People's Socialist Republic of
          + "AM" + "ARM"  // Armenia
! //      + "AN" + "ANT"  // Netherlands Antilles
          + "AO" + "AGO"  // Angola, Republic of
          + "AQ" + "ATA"  // Antarctica (the territory South of 60 deg S)
          + "AR" + "ARG"  // Argentina, Argentine Republic
          + "AS" + "ASM"  // American Samoa
          + "AT" + "AUT"  // Austria, Republic of
*** 475,482 ****
--- 477,539 ----
          + "ZA" + "ZAF"  // South Africa, Republic of
          + "ZM" + "ZMB"  // Zambia, Republic of
          + "ZW" + "ZWE"  // Zimbabwe
          ;
  
+     /**
+      * Array to hold country codes for ISO3166-3.
+      */
+      private static final String[] ISO3166_3 = {
+         "AIDJ", "ANHH", "BQAQ", "BUMM", "BYAA", "CSHH", "CSXX", "CTKI", "DDDE",
+         "DYBJ", "FQHH", "FXFR", "GEHH", "HVBF", "JTUM", "MIUM", "NHVU", "NQAQ",
+         "NTHH", "PCHH", "PUUM", "PZPA", "RHZW", "SKIN", "SUHH", "TPTL", "VDVN",
+         "WKUM", "YDYE", "YUCS", "ZRCD"
+     };
+ 
+     /**
+      * Map to hold country codes for each ISO3166 part.
+      */
+      private static Map<IsoCountryCode, Set<String>> iso3166CodesMap = new HashMap<>();
+ 
+     /**
+      * This mapping function attempts to compute value for iso3166CodesMap
+      * for each IsoCountryCode type key.
+      */
+     private static Set<String> getISOCountriesImpl(IsoCountryCode type) {
+         switch (type) {
+             case PART1_ALPHA2:
+                 return Set.of(Locale.getISOCountries());
+             case PART1_ALPHA3:
+                 return LocaleISOData.computeISO3166_1Alpha3Countries();
+             case PART3:
+                 return Set.of(ISO3166_3);
+             default:
+                 // should not happen
+                 assert false;
+                 return Collections.emptySet();
+         }
+     }
+ 
+     /**
+      * This method is called from Locale class
+      * to retrieve country code set for getISOCountries(type)
+      */
+     static Set<String> retrieveIsoCountryCodes(IsoCountryCode type) {
+        return iso3166CodesMap.computeIfAbsent(type, LocaleISOData::getISOCountriesImpl);
+     }
+ 
+     /**
+      * This method computes a set of ISO3166-1 alpha-3 country codes from
+      * existing isoCountryTable.
+      */
+     private static Set<String> computeISO3166_1Alpha3Countries() {
+         int tableLength = isoCountryTable.length();
+         String[] isoTable = new String[tableLength / 5];
+         for (int i = 0, index = 0; index < tableLength; i++, index += 5) {
+             isoTable[i] = isoCountryTable.substring(index + 2, index + 5);
+         }
+         return Set.of(isoTable);
+     }
+ 
      private LocaleISOData() {
      }
  }