1 /*
2  *******************************************************************************
3  * Copyright (C) 2009, International Business Machines Corporation and         *
4  * others. All Rights Reserved.                                                *
5  *******************************************************************************
6  */
7 package com.ibm.icu.impl;
8 
9 import java.util.MissingResourceException;
10 
11 import com.ibm.icu.util.ULocale;
12 import com.ibm.icu.util.UResourceBundle;
13 
14 /**
15  * Calendar utilities.
16  *
17  * Date/time format service classes in com.ibm.icu.text packages
18  * sometimes need to access calendar internal APIs.  But calendar
19  * classes are in com.ibm.icu.util package, so the package local
20  * cannot be used.  This class is added in com.ibm.icu.impl
21  * package for sharing some calendar internal code for calendar
22  * and date format.
23  */
24 public class CalendarUtil {
25 
26     private static ICUCache<String, String> CALTYPE_CACHE = new SimpleCache<String, String>();
27 
28     private static final String CALKEY = "calendar";
29     private static final String DEFCAL = "gregorian";
30 
31     /**
32      * Returns a calendar type for the given locale.
33      * When the given locale has calendar keyword, the
34      * value of calendar keyword is returned.  Otherwise,
35      * the default calendar type for the locale is returned.
36      * @param loc The locale
37      * @return Calendar type string, such as "gregorian"
38      */
getCalendarType(ULocale loc)39     public static String getCalendarType(ULocale loc) {
40         String calType = null;
41 
42         calType = loc.getKeywordValue(CALKEY);
43         if (calType != null) {
44             return calType;
45         }
46 
47         String baseLoc = loc.getBaseName();
48 
49         // Check the cache
50         calType = CALTYPE_CACHE.get(baseLoc);
51         if (calType != null) {
52             return calType;
53         }
54 
55         // Canonicalize, so grandfathered variant will be transformed to keywords
56         ULocale canonical = ULocale.createCanonical(loc.toString());
57         calType = canonical.getKeywordValue("calendar");
58 
59         if (calType == null) {
60             // When calendar keyword is not available, use the locale's
61             // region to get the default calendar type
62             String region = canonical.getCountry();
63             if (region.length() == 0) {
64                 ULocale fullLoc = ULocale.addLikelySubtags(canonical);
65                 region = fullLoc.getCountry();
66             }
67 
68             // Read supplementalData to get the default calendar type for
69             // the locale's region
70             try {
71                 UResourceBundle rb = UResourceBundle.getBundleInstance(
72                                         ICUResourceBundle.ICU_BASE_NAME,
73                                         "supplementalData",
74                                         ICUResourceBundle.ICU_DATA_CLASS_LOADER);
75                 UResourceBundle calPref = rb.get("calendarPreferenceData");
76                 UResourceBundle order = null;
77                 try {
78                     order = calPref.get(region);
79                 } catch (MissingResourceException mre) {
80                     // use "001" as fallback
81                     order = calPref.get("001");
82                 }
83                 // the first calendar type is the default for the region
84                 calType = order.getString(0);
85             } catch (MissingResourceException mre) {
86                 // fall through
87             }
88 
89             if (calType == null) {
90                 // Use "gregorian" as the last resort fallback.
91                 calType = DEFCAL;
92             }
93         }
94 
95         // Cache the resolved value for the next time
96         CALTYPE_CACHE.put(baseLoc, calType);
97 
98         return calType;
99     }
100 }
101