src/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.Enumeration;
   8 import java.util.Locale;
   9 import java.util.MissingResourceException;
  10 import java.util.Properties;
  11 import java.util.ResourceBundle;
  12
  13 /**
  14  * Manager for all internationalization
  15  * Responsible for loading property files
  16  * and delivering language-specific texts
  17  */
  18 public abstract class I18nManager
  19 {
  20         /** Properties object into which all the texts are copied */
  21         private static Properties _localTexts = null;
  22
  23         /** External properties file for developer testing */
  24         private static Properties _externalPropsFile = null;
  25
  26
  27         /**
  28          * Initialize the library using the (optional) locale
  29          * @param inLocale locale to use, or null for default
  30          */
  31         public static void init(Locale inLocale)
  32         {
  33                 final String BUNDLE_NAME = "tim.prune.lang.prune-texts";
  34                 final Locale BACKUP_LOCALE = new Locale("en", "GB");
  35
  36                 _localTexts = new Properties();
  37                 // Load English texts first to use as defaults
  38                 loadFromBundle(ResourceBundle.getBundle(BUNDLE_NAME, BACKUP_LOCALE));
  39
  40                 // Get bundle for selected locale, if any
  41                 try
  42                 {
  43                         if (inLocale != null)
  44                         {
  45                                 loadFromBundle(ResourceBundle.getBundle(BUNDLE_NAME, inLocale));
  46                         }
  47                         else
  48                         {
  49                                 // locale is null so just use the system default
  50                                 loadFromBundle(ResourceBundle.getBundle(BUNDLE_NAME, Locale.getDefault()));
  51                         }
  52                 }
  53                 catch (MissingResourceException mre) { // ignore error, default to english
  54                 }
  55         }
  56
  57         /**
  58          * Copy all the translations from the given bundle and store in the Properties object
  59          * overwriting the existing translations if necessary
  60          * @param inBundle bundle object loaded from file
  61          */
  62         private static void loadFromBundle(ResourceBundle inBundle)
  63         {
  64                 Enumeration<String> e = inBundle.getKeys();
  65                 while (e.hasMoreElements())
  66                 {
  67                         String key = e.nextElement();
  68                         _localTexts.setProperty(key, inBundle.getString(key));
  69                 }
  70         }
  71
  72         /**
  73          * Add a language file
  74          * @param inFilename filename of file
  75          * @throws FileNotFoundException if load failed
  76          */
  77         public static void addLanguageFile(String inFilename) throws FileNotFoundException
  78         {
  79                 FileInputStream fis = null;
  80                 boolean fileLoaded = false;
  81                 try
  82                 {
  83                         File file = new File(inFilename);
  84                         _externalPropsFile = new Properties();
  85                         fis = new FileInputStream(file);
  86                         _externalPropsFile.load(fis);
  87                         fileLoaded = true; // everything worked
  88                 }
  89                 catch (IOException ioe) {}
  90                 finally { try { fis.close();
  91                         } catch (Exception e) {}
  92                 }
  93                 // complain if file wasn't loaded, by throwing a filenotfound exception
  94                 if (!fileLoaded) throw new FileNotFoundException();
  95         }
  96
  97
  98         /**
  99          * Lookup the given key and return the associated text
 100          * @param inKey key to lookup
 101          * @return associated text, or the key if not found
 102          */
 103         public static String getText(String inKey)
 104         {
 105                 // look in external props file if available
 106                 if (_externalPropsFile != null)
 107                 {
 108                         String extText = _externalPropsFile.getProperty(inKey);
 109                         if (extText != null) return extText;
 110                 }
 111                 // look in texts if available
 112                 if (_localTexts != null)
 113                 {
 114                         try
 115                         {
 116                                 String localText = _localTexts.getProperty(inKey);
 117                                 if (localText != null) return localText;
 118                         }
 119                         catch (MissingResourceException mre) {}
 120                 }
 121                 // return the key itself
 122                 return inKey;
 123         }
 124
 125         /**
 126          * Lookup the given key and return the associated text, formatting with the number
 127          * @param inKey key to lookup (text should contain a %d)
 128          * @param inNumber number to substitute into the %d
 129          * @return associated text, or the key if not found
 130          */
 131         public static String getTextWithNumber(String inKey, int inNumber)
 132         {
 133                 String localText = getText(inKey);
 134                 try
 135                 {
 136                         localText = String.format(localText, inNumber);
 137                 }
 138                 catch (Exception e)
 139                 {} // printf formatting didn't work, maybe the placeholders are wrong?
 140                 return localText;
 141         }
 142 }