| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.jdo.util; |
| |
| import java.util.*; |
| import java.text.MessageFormat; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| |
| /** Helper class for constructing messages from bundles. The intended usage |
| * of this class is to construct a new instance bound to a bundle, as in |
| * <P> |
| * <code>I18NHelper msg = I18NHelper.getInstance("org.apache.jdo.util.jdo.Bundle");</code> |
| * <P> |
| * This call uses the class loader that loaded the I18NHelper class to find |
| * the specified Bundle. The class provides two overloaded getInstance |
| * methods allowing to specify a different class loader: |
| * {@link #getInstance(Class cls)} looks for a bundle |
| * called "Bundle.properties" located in the package of the specified class |
| * object and {@link #getInstance(String bundleName,ClassLoader loader)} |
| * uses the specified class loader to find the bundle. |
| * <P> |
| * Subsequently, instance methods can be used to format message strings |
| * using the text from the bundle, as in |
| * <P> |
| * <code>throw new JDOFatalInternalException (msg.msg("ERR_NoMetadata", cls.getName()));</code> |
| * @since 1.0.1 |
| * @version 1.1 |
| */ |
| public class I18NHelper { |
| |
| /** Bundles that have already been loaded |
| */ |
| private static Hashtable bundles = new Hashtable(); |
| |
| /** Helper instances that have already been created |
| */ |
| private static Hashtable helpers = new Hashtable(); |
| |
| /** The default locale for this VM. |
| */ |
| private static Locale locale = Locale.getDefault(); |
| |
| /** The name of the bundle used by this instance of the helper. |
| */ |
| private final String bundleName; |
| |
| /** The bundle used by this instance of the helper. |
| */ |
| private ResourceBundle bundle = null; |
| |
| /** Throwable if ResourceBundle couldn't be loaded |
| */ |
| private Throwable failure = null; |
| |
| /** The unqualified standard name of a bundle. */ |
| private static final String bundleSuffix = ".Bundle"; // NOI18N |
| |
| /** Constructor */ |
| private I18NHelper() { |
| this.bundleName = null; |
| } |
| |
| /** Constructor for an instance bound to a bundle. |
| * @param bundleName the name of the resource bundle |
| * @param loader the class loader from which to load the resource |
| * bundle |
| */ |
| private I18NHelper (String bundleName, ClassLoader loader) { |
| this.bundleName = bundleName; |
| try { |
| bundle = loadBundle (bundleName, loader); |
| } |
| catch (Throwable e) { |
| failure = e; |
| } |
| } |
| |
| /** An instance bound to a bundle. This method uses the current class |
| * loader to find the bundle. |
| * @param bundleName the name of the bundle |
| * @return the helper instance bound to the bundle |
| */ |
| public static I18NHelper getInstance (String bundleName) { |
| return getInstance (bundleName, I18NHelper.class.getClassLoader()); |
| } |
| |
| /** An instance bound to a bundle. This method figures out the bundle name |
| * for the class object's package and uses the class' class loader to |
| * find the bundle. Note, the specified class object must not be |
| * <code>null</code>. |
| * @param cls the class object from which to load the resource bundle |
| * @return the helper instance bound to the bundle |
| */ |
| public static I18NHelper getInstance (final Class cls) { |
| ClassLoader classLoader = (ClassLoader) AccessController.doPrivileged ( |
| new PrivilegedAction () { |
| public Object run () { |
| return cls.getClassLoader(); |
| } |
| } |
| ); |
| String bundle = getPackageName (cls.getName()) + bundleSuffix; |
| return getInstance (bundle, classLoader); |
| } |
| |
| /** An instance bound to a bundle. This method uses the specified class |
| * loader to find the bundle. Note, the specified class loader must not |
| * be <code>null</code>. |
| * @param bundleName the name of the bundle |
| * @param loader the class loader from which to load the resource |
| * bundle |
| * @return the helper instance bound to the bundle |
| */ |
| public static I18NHelper getInstance (String bundleName, |
| ClassLoader loader) { |
| I18NHelper helper = (I18NHelper) helpers.get (bundleName); |
| if (helper != null) { |
| return helper; |
| } |
| helper = new I18NHelper(bundleName, loader); |
| helpers.put (bundleName, helper); |
| // if two threads simultaneously create the same helper, return the first |
| // one to be put into the Hashtable. The other will be garbage collected. |
| return (I18NHelper) helpers.get (bundleName); |
| } |
| |
| /** Message formatter |
| * @param messageKey the message key |
| * @return the resolved message text |
| */ |
| public String msg (String messageKey) { |
| assertBundle (messageKey); |
| return getMessage (bundle, messageKey); |
| } |
| |
| /** Message formatter |
| * @param messageKey the message key |
| * @param arg1 the first argument |
| * @return the resolved message text |
| */ |
| public String msg (String messageKey, Object arg1) { |
| assertBundle (messageKey); |
| return getMessage (bundle, messageKey, arg1); |
| } |
| |
| /** Message formatter |
| * @param messageKey the message key |
| * @param arg1 the first argument |
| * @param arg2 the second argument |
| * @return the resolved message text |
| */ |
| public String msg (String messageKey, Object arg1, Object arg2) { |
| assertBundle (messageKey); |
| return getMessage (bundle, messageKey, arg1, arg2); |
| } |
| |
| /** Message formatter |
| * @param messageKey the message key |
| * @param arg1 the first argument |
| * @param arg2 the second argument |
| * @param arg3 the third argument |
| * @return the resolved message text |
| */ |
| public String msg (String messageKey, Object arg1, Object arg2, Object arg3) { |
| assertBundle (messageKey); |
| return getMessage (bundle, messageKey, arg1, arg2, arg3); |
| } |
| |
| /** Message formatter |
| * @param messageKey the message key |
| * @param args the array of arguments |
| * @return the resolved message text |
| */ |
| public String msg (String messageKey, Object[] args) { |
| assertBundle (messageKey); |
| return getMessage (bundle, messageKey, args); |
| } |
| |
| /** Message formatter |
| * @param messageKey the message key |
| * @param arg the argument |
| * @return the resolved message text |
| */ |
| public String msg (String messageKey, int arg) { |
| assertBundle (messageKey); |
| return getMessage(bundle, messageKey, arg); |
| } |
| |
| /** Message formatter |
| * @param messageKey the message key |
| * @param arg the argument |
| * @return the resolved message text |
| */ |
| public String msg (String messageKey, boolean arg) { |
| assertBundle (messageKey); |
| return getMessage(bundle, messageKey, arg); |
| } |
| |
| /** Returns the resource bundle used by this I18NHelper. |
| * @return the associated resource bundle |
| * @since 1.1 |
| */ |
| public ResourceBundle getResourceBundle () { |
| assertBundle (); |
| return bundle; |
| } |
| |
| //========= Internal helper methods ========== |
| |
| /** |
| * Load ResourceBundle by bundle name |
| * @param bundleName the name of the bundle |
| * @param loader the class loader from which to load the resource bundle |
| * @return the ResourceBundle |
| */ |
| final private static ResourceBundle loadBundle( |
| String bundleName, ClassLoader loader) { |
| ResourceBundle messages = (ResourceBundle)bundles.get(bundleName); |
| |
| if (messages == null) //not found as loaded - add |
| { |
| messages = ResourceBundle.getBundle(bundleName, locale, loader); |
| bundles.put(bundleName, messages); |
| } |
| return messages; |
| } |
| |
| /** Assert resources available |
| * @since 1.1 |
| * @throws RuntimeException if the resource bundle could not |
| * be loaded during construction. |
| */ |
| private void assertBundle () { |
| if (failure != null) |
| throw new RuntimeException ( |
| "No resources could be found for bundle:\"" + //NOI18N |
| bundle + "\" " + failure); //NOI18N |
| } |
| |
| /** Assert resources available |
| * @param key the message key |
| * @since 1.0.2 |
| * @throws RuntimeException if the resource bundle could not |
| * be loaded during construction. |
| */ |
| private void assertBundle (String key) { |
| if (failure != null) |
| throw new RuntimeException ( |
| "No resources could be found to annotate error message key:\"" + //NOI18N |
| key + "\" " + failure); //NOI18N |
| } |
| |
| /** |
| * Returns message as <code>String</code> |
| * @param messages the resource bundle |
| * @param messageKey the message key |
| * @return the resolved message text |
| */ |
| final private static String getMessage(ResourceBundle messages, String messageKey) |
| { |
| return messages.getString(messageKey); |
| } |
| |
| /** |
| * Formats message by adding array of arguments |
| * @param messages the resource bundle |
| * @param messageKey the message key |
| * @param msgArgs an array of arguments to substitute into the message |
| * @return the resolved message text |
| */ |
| final private static String getMessage(ResourceBundle messages, String messageKey, Object msgArgs[]) |
| { |
| for (int i=0; i<msgArgs.length; i++) { |
| if (msgArgs[i] == null) msgArgs[i] = ""; // NOI18N |
| } |
| MessageFormat formatter = new MessageFormat(messages.getString(messageKey)); |
| return formatter.format(msgArgs); |
| } |
| |
| /** |
| * Formats message by adding an <code>Object</code> argument. |
| * @param messages the resource bundle |
| * @param messageKey the message key |
| * @param arg the argument |
| * @return the resolved message text |
| */ |
| final private static String getMessage(ResourceBundle messages, String messageKey, Object arg) |
| { |
| Object []args = {arg}; |
| return getMessage(messages, messageKey, args); |
| } |
| |
| /** |
| * Formats message by adding two <code>Object</code> arguments. |
| * @param messages the resource bundle |
| * @param messageKey the message key |
| * @param arg1 the first argument |
| * @param arg2 the second argument |
| * @return the resolved message text |
| */ |
| final private static String getMessage(ResourceBundle messages, String messageKey, Object arg1, |
| Object arg2) |
| { |
| Object []args = {arg1, arg2}; |
| return getMessage(messages, messageKey, args); |
| } |
| |
| /** |
| * Formats message by adding three <code>Object</code> arguments. |
| * @param messages the resource bundle |
| * @param messageKey the message key |
| * @param arg1 the first argument |
| * @param arg2 the second argument |
| * @param arg3 the third argument |
| * @return the resolved message text |
| */ |
| final private static String getMessage(ResourceBundle messages, String messageKey, Object arg1, |
| Object arg2, Object arg3) |
| { |
| Object []args = {arg1, arg2, arg3}; |
| return getMessage(messages, messageKey, args); |
| } |
| |
| /** |
| * Formats message by adding an <code>int</code> as an argument. |
| * @param messages the resource bundle |
| * @param messageKey the message key |
| * @param arg the argument |
| * @return the resolved message text |
| */ |
| final private static String getMessage(ResourceBundle messages, String messageKey, int arg) |
| { |
| Object []args = {new Integer(arg)}; |
| return getMessage(messages, messageKey, args); |
| } |
| |
| /** |
| * Formats message by adding a <code>boolean</code> as an argument. |
| * @param messages the resource bundle |
| * @param messageKey the message key |
| * @param arg the argument |
| * @return the resolved message text |
| */ |
| final private static String getMessage(ResourceBundle messages, String messageKey, boolean arg) |
| { |
| Object []args = {String.valueOf(arg)}; |
| return getMessage(messages, messageKey, args); |
| } |
| |
| /** |
| * Returns the package portion of the specified class. |
| * @param className the name of the class from which to extract the |
| * package |
| * @return package portion of the specified class |
| */ |
| final private static String getPackageName(final String className) |
| { |
| final int index = className.lastIndexOf('.'); |
| return ((index != -1) ? className.substring(0, index) : ""); // NOI18N |
| } |
| } |
