public abstract class ResourceBundle
{
/**
+ * Maximum size of our cache of <code>ResourceBundle</code>s keyed by
+ * {@link BundleKey} instances.
+ *
+ * @see BundleKey
+ */
+ private static final int CACHE_SIZE = 100;
+
+ /**
* 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.
*/
private Locale locale;
/**
- * The resource bundle cache.
- */
- private static Map bundleCache;
-
- /**
- * 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().
+ * A VM-wide cache of resource bundles already fetched.
+ * <p>
+ * This {@link Map} is a Least Recently Used (LRU) cache, of the last
+ * {@link #CACHE_SIZE} accessed <code>ResourceBundle</code>s keyed by the
+ * tuple: default locale, resource-bundle name, resource-bundle locale, and
+ * classloader.
+ *
+ * @see BundleKey
*/
- private static final Locale emptyLocale = new Locale("");
+ private static Map bundleCache = new LinkedHashMap(CACHE_SIZE + 1, 0.75F, true)
+ {
+ public boolean removeEldestEntry(Map.Entry entry)
+ {
+ return size() > CACHE_SIZE;
+ }
+ };
/**
* The constructor. It does nothing special.
by the combination of bundle name, locale, and class loader. */
private static class BundleKey
{
+ Locale defaultLocale;
String baseName;
Locale locale;
ClassLoader classLoader;
BundleKey() {}
- BundleKey(String s, Locale l, ClassLoader cl)
+ BundleKey(Locale dl, String s, Locale l, ClassLoader cl)
{
- set(s, l, cl);
+ set(dl, s, l, cl);
}
- void set(String s, Locale l, ClassLoader cl)
+ void set(Locale dl, String s, Locale l, ClassLoader cl)
{
+ defaultLocale = dl;
baseName = s;
locale = l;
classLoader = cl;
- hashcode = baseName.hashCode() ^ locale.hashCode() ^
- classLoader.hashCode();
+ hashcode = defaultLocale.hashCode() ^ baseName.hashCode()
+ ^ locale.hashCode() ^ classLoader.hashCode();
}
public int hashCode()
if (! (o instanceof BundleKey))
return false;
BundleKey key = (BundleKey) o;
- return hashcode == key.hashcode &&
- baseName.equals(key.baseName) &&
- locale.equals(key.locale) &&
- classLoader.equals(key.classLoader);
+ return hashcode == key.hashcode
+ && defaultLocale.equals(key.defaultLocale)
+ && baseName.equals(key.baseName)
+ && locale.equals(key.locale)
+ && classLoader.equals(key.classLoader);
}
}
public static synchronized ResourceBundle getBundle
(String baseName, Locale locale, ClassLoader classLoader)
{
- // If the default locale changed since the last time we were called,
- // all cache entries are invalidated.
Locale defaultLocale = Locale.getDefault();
- if (defaultLocale != lastDefaultLocale)
- {
- bundleCache = new HashMap();
- lastDefaultLocale = defaultLocale;
- }
-
// This will throw NullPointerException if any arguments are null.
- lookupKey.set(baseName, locale, classLoader);
-
+ lookupKey.set(defaultLocale, baseName, locale, classLoader);
Object obj = bundleCache.get(lookupKey);
- ResourceBundle rb = null;
-
if (obj instanceof ResourceBundle)
+ return (ResourceBundle) obj;
+
+ if (obj == nullEntry)
+ throw new MissingResourceException("Bundle " + baseName
+ + " not found for locale " + locale
+ + " by classloader " + classLoader,
+ baseName, "");
+ // First, look for a bundle for the specified locale. We don't want
+ // the base bundle this time.
+ boolean wantBase = locale.equals(defaultLocale);
+ ResourceBundle bundle = tryBundle(baseName, locale, classLoader, wantBase);
+ // Try the default locale if neccessary.
+ if (bundle == null && ! wantBase)
+ bundle = tryBundle(baseName, defaultLocale, classLoader, true);
+
+ BundleKey key = new BundleKey(defaultLocale, baseName, locale, classLoader);
+ if (bundle == null)
{
- return (ResourceBundle) obj;
- }
- else if (obj == nullEntry)
- {
- // Lookup has failed previously. Fall through.
+ // Cache the fact that this lookup has previously failed.
+ bundleCache.put(key, nullEntry);
+ throw new MissingResourceException("Bundle " + baseName
+ + " not found for locale " + locale
+ + " by classloader " + classLoader,
+ baseName, "");
}
- else
- {
- // First, look for a bundle for the specified locale. We don't want
- // the base bundle this time.
- boolean wantBase = locale.equals(defaultLocale);
- ResourceBundle bundle = tryBundle(baseName, locale, classLoader,
- wantBase);
-
- // Try the default locale if neccessary.
- if (bundle == null && !locale.equals(defaultLocale))
- bundle = tryBundle(baseName, defaultLocale, classLoader, true);
-
- BundleKey key = new BundleKey(baseName, locale, classLoader);
- if (bundle == null)
- {
- // Cache the fact that this lookup has previously failed.
- bundleCache.put(key, nullEntry);
- }
- else
- {
- // Cache the result and return it.
- bundleCache.put(key, bundle);
- return bundle;
- }
- }
-
- throw new MissingResourceException("Bundle " + baseName
- + " not found for locale "
- + locale
- + " by classloader "
- + classLoader,
- baseName, "");
+ // Cache the result and return it.
+ bundleCache.put(key, bundle);
+ return bundle;
}
/**
*
* @return an enumeration of the keys
*/
- public abstract Enumeration getKeys();
+ public abstract Enumeration<String> getKeys();
/**
* Tries to load a class or a property file with the specified name.
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