tim/prune/I18nManager.java

   1 package tim.prune;
   2
   3 import java.io.File;
   4 import java.io.FileInputStream;
   5 import java.io.FileNotFoundException;
   6 import java.io.IOException;
   7 import java.util.Locale;
   8 import java.util.MissingResourceException;
   9 import java.util.Properties;
  10 import java.util.ResourceBundle;
  11
  12 /**
  13  * Manager for all internationalization
  14  * Responsible for loading property files
  15  * and delivering language-specific texts
  16  */
  17 public abstract class I18nManager
  18 {
  19         private static final String BUNDLE_NAME = "tim.prune.lang.prune-texts";
  20         private static final Locale BACKUP_LOCALE = new Locale("en", "GB");
  21
  22         private static ResourceBundle EnglishTexts = null;
  23         private static ResourceBundle LocalTexts = null;
  24
  25         /** External properties file for developer testing */
  26         private static Properties ExternalPropsFile = null;
  27
  28
  29         /**
  30          * Initialize the library using the (optional) locale
  31          * @param inLocale locale to use, or null for default
  32          */
  33         public static void init(Locale inLocale)
  34         {
  35                 // Load English texts first to use as defaults
  36                 EnglishTexts = ResourceBundle.getBundle(BUNDLE_NAME, BACKUP_LOCALE);
  37
  38                 // Get bundle for selected locale, if any
  39                 try
  40                 {
  41                         if (inLocale != null)
  42                         {
  43                                 LocalTexts = ResourceBundle.getBundle(BUNDLE_NAME, inLocale);
  44                         }
  45                         else
  46                         {
  47                                 // locale is null so just use the system default
  48                                 LocalTexts = ResourceBundle.getBundle(BUNDLE_NAME, Locale.getDefault());
  49                         }
  50                 }
  51                 catch (MissingResourceException mre) { // ignore error, default to english
  52                 }
  53         }
  54
  55
  56         /**
  57          * Add a language file
  58          * @param inFilename filename of file
  59          * @throws FileNotFoundException if load failed
  60          */
  61         public static void addLanguageFile(String inFilename) throws FileNotFoundException
  62         {
  63                 FileInputStream fis = null;
  64                 boolean fileLoaded = false;
  65                 try
  66                 {
  67                         File file = new File(inFilename);
  68                         ExternalPropsFile = new Properties();
  69                         fis = new FileInputStream(file);
  70                         ExternalPropsFile.load(fis);
  71                         fileLoaded = true; // everything worked
  72                 }
  73                 catch (IOException ioe) {}
  74                 finally { try { fis.close();
  75                         } catch (Exception e) {}
  76                 }
  77                 // complain if file wasn't loaded, by throwing a filenotfound exception
  78                 if (!fileLoaded) throw new FileNotFoundException();
  79         }
  80
  81
  82         /**
  83          * Lookup the given key and return the associated text
  84          * @param inKey key to lookup
  85          * @return associated text, or the key if not found
  86          */
  87         public static String getText(String inKey)
  88         {
  89                 // look in external props file if available
  90                 if (ExternalPropsFile != null)
  91                 {
  92                         String extText = ExternalPropsFile.getProperty(inKey);
  93                         if (extText != null) return extText;
  94                 }
  95                 // look in extra texts if available
  96                 if (LocalTexts != null)
  97                 {
  98                         try
  99                         {
 100                                 String localText = LocalTexts.getString(inKey);
 101                                 if (localText != null) return localText;
 102                         }
 103                         catch (MissingResourceException mre) {}
 104                 }
 105                 // look in english texts
 106                 if (EnglishTexts != null)
 107                 {
 108                         try
 109                         {
 110                                 String engText = EnglishTexts.getString(inKey);
 111                                 if (engText != null) return engText;
 112                         }
 113                         catch (MissingResourceException mre) {}
 114                 }
 115                 // return the key itself
 116                 return inKey;
 117         }
 118 }