stands for
- * the two letter ISO language code of the default locale (see
- * Locale.getDefault()).
- *
- * baseName_language code_country code_variant
- * baseName_language code_country code
- * baseName_language code
- * baseName_def. language code_def. country code_def. variant
- * baseName_def. language code_def. country code
- * baseName_def. language code
- * baseName
- *
- *
- * A bundle is backed up, by less specific bundle (omiting variant,
- * country or language). But it is not backed up by the default
- * language locale.
- *
- * If you provide a bundle for a given locale, say
- * Bundle_en_UK_POSIX, you must also provide a bundle for
- * all sub locales, ie. Bundle_en_UK, Bundle_en, and
- * Bundle.
- *
- * When a bundle is searched, we look first for a class with
- * the given name and if that is not found for a file with
- * .properties extension in the classpath. The name
- * must be a fully qualified classname (with dots as path separators).
- *
- * (Note: This implementation always backs up the class with a
- * properties file if that is existing, but you shouldn't rely on
- * this, if you want to be compatible to the standard JDK.)
- *
- * @see Locale
- * @see PropertyResourceBundle
- * @author Jochen Hoenicke */
-public abstract class ResourceBundle
-{
- /**
- * The parent bundle. This is consulted when you call getObject
- * and there is no such resource in the current bundle. This
- * field may be null.
- */
- protected ResourceBundle parent;
-
- /**
- * The locale of this resource bundle. You can read this with
- * getLocale and it is automatically set in
- * getBundle.
- */
- private Locale locale;
-
- /**
- * We override SecurityManager in order to access getClassContext().
- */
- static class Security extends SecurityManager
- {
- /** Return the ClassLoader of the class which called into this
- ResourceBundle, or null if it cannot be determined. */
- ClassLoader getCallingClassLoader()
- {
- Class[] stack = super.getClassContext();
- for (int i = 0; i < stack.length; i++)
- if (stack[i] != Security.class && stack[i] != ResourceBundle.class)
- return stack[i].getClassLoader();
- return null;
- }
- }
-
- // This will always work since java.util classes have (all) system
- // permissions.
- static Security security = (Security) AccessController.doPrivileged
- (
- new PrivilegedAction()
- {
- public Object run()
- {
- return new Security();
- }
- }
- );
-
- /**
- * The constructor. It does nothing special.
- */
- public ResourceBundle()
- {
- }
-
- /**
- * Get a String from this resource bundle. Since most localized
- * Objects are Strings, this method provides a convenient way to get
- * them without casting.
- * @param key the name of the resource.
- * @exception MissingResourceException
- * if that particular object could not be found in this bundle nor
- * the parent bundle.
- */
- public final String getString(String key) throws MissingResourceException
- {
- return (String) getObject(key);
- }
-
- /**
- * Get an array of Strings from this resource bundle. This method
- * provides a convenient way to get it without casting.
- * @param key the name of the resource.
- * @exception MissingResourceException
- * if that particular object could not be found in this bundle nor
- * the parent bundle.
- */
- public final String[] getStringArray(String key)
- throws MissingResourceException
- {
- return (String[]) getObject(key);
- }
-
- /**
- * Get an object from this resource bundle.
- * @param key the name of the resource.
- * @exception MissingResourceException
- * if that particular object could not be found in this bundle nor
- * the parent bundle.
- */
- public final Object getObject(String key) throws MissingResourceException
- {
- for (ResourceBundle bundle = this; bundle != null; bundle = bundle.parent)
- {
- try
- {
- Object o = bundle.handleGetObject(key);
- if (o != null)
- return o;
- }
- catch (MissingResourceException ex)
- {
- }
- }
- throw new MissingResourceException
- ("Key not found", getClass().getName(), key);
- }
-
- /**
- * Get the appropriate ResourceBundle for the default locale.
- * @param baseName the name of the ResourceBundle. This should be
- * a name of a Class or a properties-File. See the class
- * description for details.
- * @return the desired resource bundle
- * @exception MissingResourceException
- * if the resource bundle couldn't be found.
- */
- public static final ResourceBundle getBundle(String baseName)
- throws MissingResourceException
- {
- return getBundle(baseName, Locale.getDefault(),
- security.getCallingClassLoader());
- }
-
- /**
- * Get the appropriate ResourceBundle for the given locale.
- * @param baseName the name of the ResourceBundle. This should be
- * a name of a Class or a properties-File. See the class
- * description for details.
- * @param locale A locale.
- * @return the desired resource bundle
- * @exception MissingResourceException
- * if the resource bundle couldn't be found.
- */
- public static final ResourceBundle getBundle(String baseName,
- Locale locale)
- throws MissingResourceException
- {
- return getBundle(baseName, locale, security.getCallingClassLoader());
- }
-
- /**
- * The resource bundle cache. This is a two-level hash map: The key
- * is the class loader, the value is a new HashMap. The key of this
- * second hash map is the localized name, the value is a soft
- * references to the resource bundle. */
- private static Map resourceBundleCache = new HashMap();
-
- /**
- * The `empty' locale is created once in order to optimize
- * tryBundle().
- */
- private static final Locale emptyLocale = new Locale ("", "");
-
- /**
- * Tries to load a class or a property file with the specified name.
- * @param localizedName the name.
- * @param locale the locale, that must be used exactly.
- * @param classloader the classloader.
- * @param bundle the back up (parent) bundle
- * @return the resource bundle if that could be loaded, otherwise
- * bundle.
- */
- private static final ResourceBundle tryBundle(String localizedName,
- Locale locale,
- ClassLoader classloader,
- ResourceBundle bundle,
- HashMap cache)
- {
- {
- // First look into the cache.
- // XXX We should remove cleared references from the cache.
- Reference ref = (Reference) cache.get(localizedName);
- if (ref != null)
- {
- ResourceBundle rb = (ResourceBundle) ref.get();
- if (rb != null)
- // rb should already have the right parent, except if
- // something very strange happened.
- return rb;
- }
- }
-
- // foundBundle holds exact matches for the localizedName resource
- // bundle, which may later be cached.
- ResourceBundle foundBundle = null;
-
- try
- {
- java.io.InputStream is;
- final String resourceName =
- localizedName.replace('.', '/') + ".properties";
- if (classloader == null)
- is = ClassLoader.getSystemResourceAsStream (resourceName);
- else
- is = classloader.getResourceAsStream (resourceName);
- if (is != null)
- {
- foundBundle = new PropertyResourceBundle(is);
- foundBundle.parent = bundle;
- foundBundle.locale = locale;
- }
- }
- catch (java.io.IOException ex)
- {
- }
-
- try
- {
- Class rbClass;
- if (classloader == null)
- rbClass = Class.forName(localizedName);
- else
- rbClass = classloader.loadClass(localizedName);
- foundBundle = (ResourceBundle) rbClass.newInstance();
- foundBundle.parent = bundle;
- foundBundle.locale = locale;
- }
- catch (ClassNotFoundException ex)
- {
- }
- catch (IllegalAccessException ex)
- {
- }
- catch (InstantiationException ex)
- {
- // ignore them all
- // XXX should we also ignore ClassCastException?
- }
-
- if (foundBundle != null)
- cache.put(localizedName, new SoftReference(foundBundle));
-
- return foundBundle != null ? foundBundle : bundle;
- }
-
- /**
- * Tries to load a the bundle for a given locale, also loads the backup
- * locales with the same language.
- *
- * @param name the name.
- * @param locale the locale, that must be used exactly.
- * @param classloader the classloader.
- * @param bundle the back up (parent) bundle
- * @return the resource bundle if that could be loaded, otherwise
- * bundle.
- */
- private static final ResourceBundle tryLocalBundle(String baseName,
- Locale locale,
- ClassLoader classloader,
- ResourceBundle bundle,
- HashMap cache)
- {
- final String language = locale.getLanguage();
-
- if (language.length() > 0)
- {
- final String country = locale.getCountry();
- String name = baseName + "_" + language;
-
- if (country.length() != 0)
- {
- bundle = tryBundle(name,
- new Locale(language, ""),
- classloader, bundle, cache);
-
- name += "_" + country;
-
- final String variant = locale.getVariant();
-
- if (variant.length() != 0)
- {
- bundle = tryBundle(name,
- new Locale(language,
- country),
- classloader, bundle, cache);
-
- name += "_" + variant;
- }
- }
- bundle = tryBundle(name, locale, classloader, bundle, cache);
- }
- return bundle;
- }
-
- /**
- * Get the appropriate ResourceBundle for the given locale.
- * @param baseName the name of the ResourceBundle. This should be
- * a name of a Class or a properties file. See the class
- * description for details.
- * @param locale A locale.
- * @param classloader a ClassLoader.
- * @return the desired resource bundle
- * @exception MissingResourceException
- * if the resource bundle couldn't be found.
- */
- // This method is synchronized so that the cache is properly
- // handled.
- public static final synchronized ResourceBundle getBundle(String baseName,
- Locale locale,
- ClassLoader classLoader)
- throws MissingResourceException
- {
- // This implementation searches the bundle in the reverse direction
- // and builds the parent chain on the fly.
-
- HashMap cache = (HashMap) resourceBundleCache.get(classLoader);
- if (cache == null)
- {
- cache = new HashMap();
- resourceBundleCache.put(classLoader, cache);
- }
- else
- {
- // Fast path: If baseName + "_" + locale is in cache use it.
- String name = baseName + "_" + locale.toString();
- Reference ref = (Reference) cache.get(name);
- if (ref != null)
- {
- ResourceBundle rb = (ResourceBundle) ref.get();
- if (rb != null)
- // rb should already have the right parent, except if
- // something very strange happened.
- return rb;
- }
- }
-
- ResourceBundle baseBundle = tryBundle(baseName, emptyLocale,
- classLoader, null, cache);
- if (baseBundle == null)
- // JDK says, that if one provides a bundle base_en_UK, one
- // must also provide the bundles base_en and base.
- // This implies that if there is no bundle for base, there
- // is no bundle at all.
- throw new MissingResourceException("Bundle " + baseName + " not found", baseName, "");
-
- // Now use the default locale.
- ResourceBundle bundle = tryLocalBundle(baseName, locale,
- classLoader, baseBundle, cache);
- if (bundle == baseBundle && !locale.equals(Locale.getDefault()))
- {
- bundle = tryLocalBundle(baseName, Locale.getDefault(),
- classLoader, baseBundle, cache);
- }
- return bundle;
- }
-
- /**
- * Return the actual locale of this bundle. You can use it after
- * calling getBundle, to know if the bundle for the desired locale
- * was loaded or if the fall back was used.
- */
- public Locale getLocale()
- {
- return locale;
- }
-
- /**
- * Set the parent of this bundle. This is consulted when you call
- * getObject and there is no such resource in the current bundle.
- * @param parent the parent of this bundle.
- */
- protected void setParent(ResourceBundle parent)
- {
- // Shall we ignore the old parent?
- this.parent = parent;
- }
-
- /**
- * Override this method to provide the resource for a keys. This gets
- * called by getObject. If you don't have a resource
- * for the given key, you should return null instead throwing a
- * MissingResourceException. You don't have to ask the parent,
- * getObject() already does this.
- *
- * @param key The key of the resource.
- * @return The resource for the key, or null if not in bundle.
- * @exception MissingResourceException
- * you shouldn't throw this.
- */
- protected abstract Object handleGetObject(String key)
- throws MissingResourceException;
-
- /**
- * This method should return all keys for which a resource exists.
- * @return An enumeration of the keys.
- */
- public abstract Enumeration getKeys();
-}