-/* Copyright (C) 1998, 1999 Cygnus Solutions
+/* ResourceBundle -- aids in loading resource bundles
+ Copyright (C) 1998, 1999, 2001, 2002, 2003 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING. If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library. Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module. An independent module is a module which is not derived from
+or based on this library. If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so. If you do not wish to do so, delete this
+exception statement from your version. */
- This file is part of libgcj.
-
-This software is copyrighted work licensed under the terms of the
-Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
-details. */
package java.util;
+import java.lang.ref.Reference;
+import java.lang.ref.SoftReference;
import java.io.InputStream;
+import java.io.IOException;
+import gnu.classpath.Configuration;
/**
- * @author Anthony Green <green@cygnus.com>
- * @date November 26, 1998.
+ * A resource bundle contains locale-specific data. If you need localized
+ * data, you can load a resource bundle that matches the locale with
+ * <code>getBundle</code>. Now you can get your object by calling
+ * <code>getObject</code> or <code>getString</code> on that bundle.
+ *
+ * <p>When a bundle is demanded for a specific locale, the ResourceBundle
+ * is searched in following order (<i>def. language<i> stands for the
+ * two letter ISO language code of the default locale (see
+ * <code>Locale.getDefault()</code>).
+ *
+<pre>baseName_<i>language code</i>_<i>country code</i>_<i>variant</i>
+baseName_<i>language code</i>_<i>country code</i>
+baseName_<i>language code</i>
+baseName_<i>def. language</i>_<i>def. country</i>_<i>def. variant</i>
+baseName_<i>def. language</i>_<i>def. country</i>
+baseName_<i>def. language</i>
+baseName</pre>
+ *
+ * <p>A bundle is backed up by less specific bundles (omitting variant, country
+ * or language). But it is not backed up by the default language locale.
+ *
+ * <p>If you provide a bundle for a given locale, say
+ * <code>Bundle_en_UK_POSIX</code>, you must also provide a bundle for
+ * all sub locales, ie. <code>Bundle_en_UK</code>, <code>Bundle_en</code>, and
+ * <code>Bundle</code>.
+ *
+ * <p>When a bundle is searched, we look first for a class with the given
+ * name, then for a file with <code>.properties</code> extension in the
+ * classpath. The name must be a fully qualified classname (with dots as
+ * path separators).
+ *
+ * <p>(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.)
+ *
+ * @author Jochen Hoenicke
+ * @author Eric Blake (ebb9@email.byu.edu)
+ * @see Locale
+ * @see ListResourceBundle
+ * @see PropertyResourceBundle
+ * @since 1.1
+ * @status updated to 1.4
*/
-
-/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3,
- * and "The Java Language Specification", ISBN 0-201-63451-1. */
-
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;
- // This is used to cache resource bundles.
- private static Hashtable resource_cache = new Hashtable ();
-
- public ResourceBundle ()
- {
- }
-
- public final String getString (String key) throws MissingResourceException
- {
- return (String) getObject(key);
- }
-
- public final String[] getStringArray (String key)
- throws MissingResourceException
- {
- return (String[]) getObject(key);
- }
-
- public final Object getObject(String key) throws MissingResourceException
- {
- Object result;
-
- try
- {
- return handleGetObject (key);
- }
+ /**
+ * The locale of this resource bundle. You can read this with
+ * <code>getLocale</code> and it is automatically set in
+ * <code>getBundle</code>.
+ */
+ private Locale locale;
+
+ private static native ClassLoader 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;
+
+ /**
+ * The last default Locale we saw. If this ever changes then we have to
+ * reset our caches.
+ */
+ private static Locale lastDefaultLocale;
+
+ /**
+ * The `empty' locale is created once in order to optimize
+ * tryBundle().
+ */
+ private static final Locale emptyLocale = new Locale("");
+
+ /**
+ * 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
+ * @throws MissingResourceException if the resource can't be found
+ * @throws NullPointerException if key is null
+ * @throws ClassCastException if resource is not a string
+ */
+ public final String getString(String key)
+ {
+ 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
+ * @throws MissingResourceException if the resource can't be found
+ * @throws NullPointerException if key is null
+ * @throws ClassCastException if resource is not a string
+ */
+ public final String[] getStringArray(String key)
+ {
+ return (String[]) getObject(key);
+ }
+
+ /**
+ * Get an object from this resource bundle. This will call
+ * <code>handleGetObject</code> for this resource and all of its parents,
+ * until it finds a non-null resource.
+ *
+ * @param key the name of the resource
+ * @throws MissingResourceException if the resource can't be found
+ * @throws NullPointerException if key is null
+ */
+ public final Object getObject(String key)
+ {
+ for (ResourceBundle bundle = this; bundle != null; bundle = bundle.parent)
+ try
+ {
+ Object o = bundle.handleGetObject(key);
+ if (o != null)
+ return o;
+ }
catch (MissingResourceException ex)
- {
- if (parent != null)
- return parent.getObject(key);
- else
- throw ex;
- }
- }
-
- public static final ResourceBundle getBundle(String baseName)
- throws MissingResourceException
- {
- return getBundle(baseName, Locale.getDefault());
- }
-
- // Start searching with the name bundleName. Continue searching by
- // stripping off the '_' delimited tails until the search name is
- // the same as stopHere.
- private static final ResourceBundle trySomeGetBundle (String bundleName,
- String stopHere)
- {
- Class rbc;
- ResourceBundle needs_parent = null, r, result = null;
-
- while (true)
- {
- try
- {
- rbc = Class.forName(bundleName);
- r = null;
- try
- {
- r = (ResourceBundle) rbc.newInstance();
- }
- catch (IllegalAccessException ex)
- {
- // Fall through
- }
- catch (InstantiationException ex)
- {
- // Fall through
- }
- if (r != null)
- {
- if (result == null)
- result = r;
- if (needs_parent != null)
- {
- // We've been through the loop one or more times
- // already. Set the parent and keep going.
- needs_parent.setParent(r);
- }
- needs_parent = r;
- }
- }
- catch (ClassNotFoundException ex)
- {
- // Fall through.
- }
-
- // Look for a properties file.
+ {
+ }
+
+ throw new MissingResourceException("Key not found", getClass().getName(),
+ key);
+ }
+
+ /**
+ * 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.
+ *
+ * @return the bundle's locale
+ */
+ public Locale getLocale()
+ {
+ return locale;
+ }
+
+ /**
+ * Set the parent of this bundle. The parent 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)
+ {
+ this.parent = parent;
+ }
+
+ /**
+ * Get the appropriate ResourceBundle for the default locale. This is like
+ * calling <code>getBundle(baseName, Locale.getDefault(),
+ * getClass().getClassLoader()</code>, except that any security check of
+ * getClassLoader won't fail.
+ *
+ * @param baseName the name of the ResourceBundle
+ * @return the desired resource bundle
+ * @throws MissingResourceException if the resource bundle can't be found
+ * @throws NullPointerException if baseName is null
+ */
+ public static final ResourceBundle getBundle(String baseName)
+ {
+ return getBundle(baseName, Locale.getDefault(),
+ getCallingClassLoader());
+ }
+
+ /**
+ * Get the appropriate ResourceBundle for the given locale. This is like
+ * calling <code>getBundle(baseName, locale,
+ * getClass().getClassLoader()</code>, except that any security check of
+ * getClassLoader won't fail.
+ *
+ * @param baseName the name of the ResourceBundle
+ * @param locale A locale
+ * @return the desired resource bundle
+ * @throws MissingResourceException if the resource bundle can't be found
+ * @throws NullPointerException if baseName or locale is null
+ */
+ public static final ResourceBundle getBundle(String baseName,
+ Locale locale)
+ {
+ return getBundle(baseName, locale, getCallingClassLoader());
+ }
+
+ /**
+ * Get the appropriate ResourceBundle for the given locale. The following
+ * strategy is used:
+ *
+ * <p>A sequence of candidate bundle names are generated, and tested in
+ * this order, where the suffix 1 means the string from the specified
+ * locale, and the suffix 2 means the string from the default locale:<ul>
+ * <li>baseName + "_" + language1 + "_" + country1 + "_" + variant1</li>
+ * <li>baseName + "_" + language1 + "_" + country1</li>
+ * <li>baseName + "_" + language1</li>
+ * <li>baseName + "_" + language2 + "_" + country2 + "_" + variant2</li>
+ * <li>baseName + "_" + language2 + "_" + country2</li>
+ * <li>baseName + "_" + language2<li>
+ * <li>baseName</li>
+ * </ul>
+ *
+ * <p>In the sequence, entries with an empty string are ignored. Next,
+ * <code>getBundle</code> tries to instantiate the resource bundle:<ul>
+ * <li>First, an attempt is made to load a class in the specified classloader
+ * which is a subclass of ResourceBundle, and which has a public constructor
+ * with no arguments, via reflection.</li>
+ * <li>Next, a search is made for a property resource file, by replacing
+ * '.' with '/' and appending ".properties", and using
+ * ClassLoader.getResource(). If a file is found, then a
+ * PropertyResourceBundle is created from the file's contents.</li>
+ * </ul>
+ * If no resource bundle was found, a MissingResourceException is thrown.
+ *
+ * <p>Next, the parent chain is implemented. The remaining candidate names
+ * in the above sequence are tested in a similar manner, and if any results
+ * in a resource bundle, it is assigned as the parent of the first bundle
+ * using the <code>setParent</code> method (unless the first bundle already
+ * has a parent).
+ *
+ * <p>For example, suppose the following class and property files are
+ * provided: MyResources.class, MyResources_fr_CH.properties,
+ * MyResources_fr_CH.class, MyResources_fr.properties,
+ * MyResources_en.properties, and MyResources_es_ES.class. The contents of
+ * all files are valid (that is, public non-abstract subclasses of
+ * ResourceBundle with public nullary constructors for the ".class" files,
+ * syntactically correct ".properties" files). The default locale is
+ * Locale("en", "UK").
+ *
+ * <p>Calling getBundle with the shown locale argument values instantiates
+ * resource bundles from the following sources:<ul>
+ * <li>Locale("fr", "CH"): result MyResources_fr_CH.class, parent
+ * MyResources_fr.properties, parent MyResources.class</li>
+ * <li>Locale("fr", "FR"): result MyResources_fr.properties, parent
+ * MyResources.class</li>
+ * <li>Locale("de", "DE"): result MyResources_en.properties, parent
+ * MyResources.class</li>
+ * <li>Locale("en", "US"): result MyResources_en.properties, parent
+ * MyResources.class</li>
+ * <li>Locale("es", "ES"): result MyResources_es_ES.class, parent
+ * MyResources.class</li>
+ * </ul>
+ * The file MyResources_fr_CH.properties is never used because it is hidden
+ * by MyResources_fr_CH.class.
+ *
+ * @param baseName the name of the ResourceBundle
+ * @param locale A locale
+ * @param classloader a ClassLoader
+ * @return the desired resource bundle
+ * @throws MissingResourceException if the resource bundle can't be found
+ * @throws NullPointerException if any argument is null
+ * @since 1.2
+ */
+ // This method is synchronized so that the cache is properly
+ // handled.
+ public static final synchronized ResourceBundle getBundle
+ (String baseName, Locale locale, ClassLoader classLoader)
+ {
+ // This implementation searches the bundle in the reverse direction
+ // and builds the parent chain on the fly.
+ Locale defaultLocale = Locale.getDefault();
+ if (defaultLocale != lastDefaultLocale)
+ {
+ resourceBundleCache = new HashMap();
+ lastDefaultLocale = defaultLocale;
+ }
+ HashMap cache = (HashMap) resourceBundleCache.get(classLoader);
+ StringBuffer sb = new StringBuffer(60);
+ sb.append(baseName).append('_').append(locale);
+ String name = sb.toString();
+
+ if (cache == null)
+ {
+ cache = new HashMap();
+ resourceBundleCache.put(classLoader, cache);
+ }
+ else if (cache.containsKey(name))
+ {
+ Reference ref = (Reference) cache.get(name);
+ ResourceBundle result = null;
+ // If REF is null, that means that we added a `null' value to
+ // the hash map. That means we failed to find the bundle
+ // previously, and we cached that fact. The JDK does this, so
+ // it must be ok.
+ if (ref == null)
+ throw new MissingResourceException("Bundle " + baseName
+ + " not found",
+ baseName, "");
+ else
{
- InputStream i =
- ClassLoader.getSystemResourceAsStream (bundleName.replace ('.', '/')
- + ".properties");
- if (i != null)
+ ResourceBundle rb = (ResourceBundle) ref.get();
+ if (rb != null)
{
- try {
- return new PropertyResourceBundle (i);
- } catch (java.io.IOException e) {
- // The docs don't appear to define what happens in
- // this case, but it seems like continuing the
- // search is a reasonable thing to do.
- }
+ // RB should already have the right parent, except if
+ // something very strange happened.
+ return rb;
}
+ // If RB is null, then we previously found it but it was
+ // collected. So we try again.
}
-
- if (bundleName.equals(stopHere))
- return result;
- else
- {
- int last = bundleName.lastIndexOf('_');
-
- // No more underscores?
- if (last == -1)
- return result;
-
- // Loop around, testing this new shorter name.
- bundleName = bundleName.substring(0, last);
- }
- }
- }
-
- // Search for bundles, but stop at baseName_language (if required).
- // This is synchronized so that the cache works correctly.
- private static final synchronized ResourceBundle
- partialGetBundle (String baseName, Locale locale, boolean langStop)
- {
- ResourceBundle rb;
-
- // Explicitly invoke locale.toString() to force a
- // NullPointerException when required.
- String bundleName = baseName + "_" + locale.toString();
-
- // Check the cache.
- Object obj = resource_cache.get(bundleName);
- if (obj != null)
- return (ResourceBundle) obj;
-
- String stopHere = (baseName
- + (langStop ? ("_" + locale.getLanguage()) : ""));
-
-
- rb = trySomeGetBundle(bundleName, stopHere);
- if (rb != null)
- resource_cache.put(bundleName, rb);
-
- return rb;
- }
-
- public static final ResourceBundle getBundle (String baseName,
- Locale locale)
- throws MissingResourceException
- {
- ResourceBundle rb;
- Class rbc;
-
- if (baseName == null)
- throw new NullPointerException ();
-
- rb = partialGetBundle(baseName, locale, false);
- if (rb != null)
- return rb;
-
- // Finally, try the default locale.
- if (! locale.equals(Locale.getDefault()))
- {
- rb = partialGetBundle(baseName, Locale.getDefault(), true);
- if (rb != null)
- return rb;
- }
-
- throw new MissingResourceException("can't load bundle",
- baseName,
- "bundle");
- }
-
- protected void setParent(ResourceBundle parent)
- {
- this.parent = parent;
- }
-
- protected abstract Object handleGetObject(String key)
- throws MissingResourceException;
-
+ }
+
+ // It is ok if this returns null. We aren't required to have the
+ // base bundle.
+ ResourceBundle baseBundle = tryBundle(baseName, emptyLocale,
+ classLoader, null, cache);
+
+ // Now use our locale, followed by the default locale. We only
+ // need to try the default locale if our locale is different, and
+ // if our locale failed to yield a result other than the base
+ // bundle.
+ ResourceBundle bundle = tryLocalBundle(baseName, locale,
+ classLoader, baseBundle, cache);
+ if (bundle == baseBundle && !locale.equals(defaultLocale))
+ {
+ bundle = tryLocalBundle(baseName, defaultLocale,
+ classLoader, baseBundle, cache);
+ // We need to record that the argument locale maps to the
+ // bundle we just found. If we didn't find a bundle, record
+ // that instead.
+ if (bundle == null)
+ cache.put(name, null);
+ else
+ cache.put(name, new SoftReference(bundle));
+ }
+
+ if (bundle == null)
+ throw new MissingResourceException("Bundle " + baseName + " not found",
+ baseName, "");
+
+ return bundle;
+ }
+
+ /**
+ * Override this method to provide the resource for a keys. This gets
+ * called by <code>getObject</code>. 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; nor should you throw a MissingResourceException.
+ *
+ * @param key the key of the resource
+ * @return the resource for the key, or null if not in bundle
+ * @throws NullPointerException if key is null
+ */
+ protected abstract Object handleGetObject(String key);
+
+ /**
+ * This method should return all keys for which a resource exists; you
+ * should include the enumeration of any parent's keys, after filtering out
+ * duplicates.
+ *
+ * @return an enumeration of the keys
+ */
public abstract Enumeration getKeys();
+
+ /**
+ * 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 backup (parent) bundle
+ * @return the resource bundle if it was loaded, otherwise the backup
+ */
+ private static final ResourceBundle tryBundle(String localizedName,
+ Locale locale,
+ ClassLoader classloader,
+ ResourceBundle bundle,
+ HashMap cache)
+ {
+ // First look into the cache.
+ if (cache.containsKey(localizedName))
+ {
+ Reference ref = (Reference) cache.get(localizedName);
+ ResourceBundle result = null;
+ // If REF is null, that means that we added a `null' value to
+ // the hash map. That means we failed to find the bundle
+ // previously, and we cached that fact. The JDK does this, so
+ // it must be ok.
+ if (ref == null)
+ return null;
+ else
+ {
+ ResourceBundle rb = (ResourceBundle) ref.get();
+ if (rb != null)
+ {
+ // RB should already have the right parent, except if
+ // something very strange happened.
+ return rb;
+ }
+ // If RB is null, then we previously found it but it was
+ // collected. So we try again.
+ }
+ }
+
+ // foundBundle holds exact matches for the localizedName resource
+ // bundle, which may later be cached.
+ ResourceBundle foundBundle = null;
+ 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 (Exception ex)
+ {
+ // ignore them all
+ foundBundle = null;
+ }
+ if (foundBundle == null)
+ {
+ try
+ {
+ 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 (IOException ex)
+ {
+ }
+ }
+
+ // Put the result into the hash table. If we didn't find anything
+ // here, we record our parent bundle. If we record `null' that means
+ // nothing, not even the base, was found.
+ if (foundBundle == null)
+ foundBundle = bundle;
+ if (foundBundle == null)
+ cache.put(localizedName, null);
+ else
+ cache.put(localizedName, new SoftReference(foundBundle));
+ return foundBundle;
+ }
+
+ /**
+ * 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
+ * @param classloader the classloader
+ * @param bundle the backup (parent) bundle
+ * @return the resource bundle if it was loaded, otherwise the backup
+ */
+ private static final ResourceBundle tryLocalBundle(String baseName,
+ Locale locale,
+ ClassLoader classloader,
+ ResourceBundle bundle,
+ HashMap cache)
+ {
+ final String language = locale.getLanguage();
+ final String country = locale.getCountry();
+ final String variant = locale.getVariant();
+
+ StringBuffer sb = new StringBuffer(60);
+ sb.append(baseName);
+ sb.append('_');
+
+ if (language.length() > 0)
+ {
+ sb.append(language);
+ bundle = tryBundle(sb.toString(), new Locale(language),
+ classloader, bundle, cache);
+ }
+ // If LANGUAGE was empty, we still need to try the other
+ // components, and the `_' is required.
+ sb.append('_');
+
+ if (country.length() > 0)
+ {
+ sb.append(country);
+ bundle = tryBundle(sb.toString(), new Locale(language, country),
+ classloader, bundle, cache);
+ }
+ sb.append('_');
+
+ if (variant.length() > 0)
+ {
+ sb.append(variant);
+ bundle = tryBundle(sb.toString(), locale,
+ classloader, bundle, cache);
+ }
+
+ return bundle;
+ }
}
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