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      1 //  2016 and later: Unicode, Inc. and others.
      2 // License & terms of use: http://www.unicode.org/copyright.html#License
      3 /*
      4  *******************************************************************************
      5  * Copyright (C) 2009-2014, International Business Machines Corporation and
      6  * others. All Rights Reserved.
      7  *******************************************************************************
      8  */
      9 package com.ibm.icu.impl;
     10 
     11 import com.ibm.icu.util.ULocale;
     12 import com.ibm.icu.util.UResourceBundle;
     13 
     14 /**
     15  * Static utility functions for probing resource tables, used by ULocale and
     16  * LocaleDisplayNames.
     17  */
     18 public class ICUResourceTableAccess {
     19     /**
     20      * Utility to fetch locale display data from resource bundle tables.  Convenience
     21      * wrapper for {@link #getTableString(ICUResourceBundle, String, String, String, String)}.
     22      */
     23     public static String getTableString(String path, ULocale locale, String tableName,
     24             String itemName, String defaultValue) {
     25         ICUResourceBundle bundle = (ICUResourceBundle) UResourceBundle.
     26             getBundleInstance(path, locale.getBaseName());
     27         return getTableString(bundle, tableName, null, itemName, defaultValue);
     28     }
     29 
     30     /**
     31      * Utility to fetch locale display data from resource bundle tables.  Uses fallback
     32      * through the "Fallback" resource if available.
     33      */
     34     public static String getTableString(ICUResourceBundle bundle, String tableName,
     35             String subtableName, String item, String defaultValue) {
     36         String result = null;
     37         try {
     38             for (;;) {
     39                 ICUResourceBundle table = bundle.findWithFallback(tableName);
     40                 if (table == null) {
     41                     return defaultValue;
     42                 }
     43                 ICUResourceBundle stable = table;
     44                 if (subtableName != null) {
     45                     stable = table.findWithFallback(subtableName);
     46                 }
     47                 if (stable != null) {
     48                     result = stable.findStringWithFallback(item);
     49                     if (result != null) {
     50                         break; // possible real exception
     51                     }
     52                 }
     53 
     54                 // if we get here, stable was null, or there was no string for the item
     55                 if (subtableName == null) {
     56                     // may be a deprecated code
     57                     String currentName = null;
     58                     if (tableName.equals("Countries")) {
     59                         currentName = LocaleIDs.getCurrentCountryID(item);
     60                     } else if (tableName.equals("Languages")) {
     61                         currentName = LocaleIDs.getCurrentLanguageID(item);
     62                     }
     63                     if (currentName != null) {
     64                         result = table.findStringWithFallback(currentName);
     65                         if (result != null) {
     66                             break; // possible real exception
     67                         }
     68                     }
     69                 }
     70 
     71                 // still can't figure it out? try the fallback mechanism
     72                 String fallbackLocale = table.findStringWithFallback("Fallback"); // again, possible exception
     73                 if (fallbackLocale == null) {
     74                     return defaultValue;
     75                 }
     76 
     77                 if (fallbackLocale.length() == 0) {
     78                     fallbackLocale = "root";
     79                 }
     80 
     81                 if (fallbackLocale.equals(table.getULocale().getName())) {
     82                     return defaultValue;
     83                 }
     84 
     85                 bundle = (ICUResourceBundle) UResourceBundle.getBundleInstance(
     86                         bundle.getBaseName(), fallbackLocale);
     87             }
     88         } catch (Exception e) {
     89             // If something is seriously wrong, we might call getString on a resource that is
     90             // not a string.  That will throw an exception, which we catch and ignore here.
     91         }
     92 
     93         // If the result is empty return item instead
     94         return ((result != null && result.length() > 0) ? result : defaultValue);
     95     }
     96 }
     97