jforum example source code file (I18n.java)

This example jforum source code file (I18n.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - jforum tags/keywords

exception, fileinputstream, fileinputstream, forumexception, hashmap, i18n, i18n, io, ioexception, object, properties, properties, string, string, text, usersession, util

The jforum I18n.java source code

/*
 * Copyright (c) JForum Team
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, 
 * with or without modification, are permitted provided 
 * that the following conditions are met:
 * 
 * 1) Redistributions of source code must retain the above 
 * copyright notice, this list of conditions and the 
 * following  disclaimer.
 * 2)  Redistributions in binary form must reproduce the 
 * above copyright notice, this list of conditions and 
 * the following disclaimer in the documentation and/or 
 * other materials provided with the distribution.
 * 3) Neither the name of "Rafael Steil" nor 
 * the names of its contributors may be used to endorse 
 * or promote products derived from this software without 
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT 
 * HOLDERS AND CONTRIBUTORS "AS IS" AND ANY 
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, 
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 
 * THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 
 * IN CONTRACT, STRICT LIABILITY, OR TORT 
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE
 * 
 * This file creation date: Mar 10, 2003 / 9:28:40 PM
 * The JForum Project
 * http://www.jforum.net
 */
package net.jforum.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import net.jforum.SessionFacade;
import net.jforum.entities.UserSession;
import net.jforum.exceptions.ForumException;
import net.jforum.util.preferences.ConfigKeys;
import net.jforum.util.preferences.SystemGlobals;

import org.apache.log4j.Logger;

import freemarker.template.SimpleSequence;

/**
 * I18n (Internationalization) class implementation. Does nothing of special, just loads the
 * messages into memory and provides a static method to acess them.
 * 
 * @author Rafael Steil
 * @author James Yong
 * @version $Id: I18n.java,v 1.36 2007/07/08 14:11:43 rafaelsteil Exp $
 */
public class I18n
{
	private static final Logger logger = Logger.getLogger(I18n.class);

	private static I18n classInstance = new I18n();

	private static Map messagesMap = new HashMap();

	private static Properties localeNames = new Properties();

	private static String defaultName;

	private static String baseDir;

	private static List watching = new ArrayList();

	public static final String CANNOT_DELETE_GROUP = "CannotDeleteGroup";

	public static final String CANNOT_DELETE_CATEGORY = "CannotDeleteCategory";

	public static final String CANNOT_DELETE_BANNER = "CannotDeleteBanner";

	private I18n()
	{
	}

	/**
	 * Gets the singleton
	 * 
	 * @return Instance of I18n class
	 */
	public static I18n getInstance()
	{
		return classInstance;
	}

	/**
	 * Load the default I18n file
	 * 
	 */
	public static synchronized void load()
	{
		baseDir = SystemGlobals.getApplicationResourceDir() + "/" + SystemGlobals.getValue(ConfigKeys.LOCALES_DIR);

		loadLocales();

		defaultName = SystemGlobals.getValue(ConfigKeys.I18N_DEFAULT_ADMIN);
		load(defaultName, null);

		String custom = SystemGlobals.getValue(ConfigKeys.I18N_DEFAULT);
		if (!custom.equals(defaultName)) {
			load(custom, defaultName);
			defaultName = custom;
		}
	}

	public static void changeBoardDefault(String newDefaultLanguage)
	{
		load(newDefaultLanguage, SystemGlobals.getValue(ConfigKeys.I18N_DEFAULT_ADMIN));
		defaultName = newDefaultLanguage;
	}

	private static void loadLocales()
	{
		FileInputStream fis = null;
		
		try {
			fis = new FileInputStream(baseDir + SystemGlobals.getValue(ConfigKeys.LOCALES_NAMES));
			localeNames.load(fis);
		}
		catch (IOException e) {
			throw new ForumException(e);
		}
		finally {
			if (fis != null) {
				try { fis.close(); } catch (Exception e) {}
			}
		}
	}

	static void load(String localeName, String mergeWith)
	{
		load(localeName, mergeWith, false);
	}

	static void load(String localeName, String mergeWith, boolean force)
	{
		if (!force && (localeName == null || localeName.trim().equals("") || I18n.contains(localeName))) {
			return;
		}

		if (localeNames.size() == 0) {
			loadLocales();
		}

		Properties p = new Properties();

		if (mergeWith != null) {
			if (!I18n.contains(mergeWith)) {
				load(mergeWith, null);
			}

			p.putAll((Properties) messagesMap.get(mergeWith));
		}
		
		FileInputStream fis = null;

		try {
			String filename = baseDir + localeNames.getProperty(localeName);
			
			// If the requested locale does not exist, use the default
			if (!new File(filename).exists()) {
				filename = baseDir + localeNames.getProperty(SystemGlobals.getValue(ConfigKeys.I18N_DEFAULT_ADMIN));
			}
			
			fis = new FileInputStream(filename);
			p.load(fis);
		}
		catch (IOException e) {
			throw new ForumException(e);
		}
		finally {
			if (fis != null) {
				try { fis.close(); } catch (Exception e) {}
			}
		}
		
		messagesMap.put(localeName, p);

		watchForChanges(localeName);
	}

	/**
	 * Loads a new locale. If <code>localeName is either null or empty, or if the locale is
	 * already loaded, the method will return without executing any code.
	 * 
	 * @param localeName
	 *            The locale name to load
	 */
	public static void load(String localeName)
	{
		load(localeName, SystemGlobals.getValue(ConfigKeys.I18N_DEFAULT));
	}

	public static void reset()
	{
		messagesMap = new HashMap();
		localeNames = new Properties();
		defaultName = null;
	}

	private static void watchForChanges(final String localeName)
	{
		if (!watching.contains(localeName)) {
			watching.add(localeName);

			int fileChangesDelay = SystemGlobals.getIntValue(ConfigKeys.FILECHANGES_DELAY);

			if (fileChangesDelay > 0) {
				FileMonitor.getInstance().addFileChangeListener(new FileChangeListener() {
					/**
					 * @see net.jforum.util.FileChangeListener#fileChanged(java.lang.String)
					 */
					public void fileChanged(String filename)
					{
						if (logger.isDebugEnabled()) {
							logger.info("Reloading i18n for " + localeName);
						}

						I18n.load(localeName, SystemGlobals.getValue(ConfigKeys.I18N_DEFAULT), true);
					}
				}, baseDir + localeNames.getProperty(localeName), fileChangesDelay);
			}
		}
	}

	/**
	 * Gets a I18N (internationalized) message.
	 * 
	 * @param localeName
	 *            The locale name to retrieve the messages from
	 * @param messageName
	 *            The message name to retrieve. Must be a valid entry into the file specified by
	 *            <code>i18n.file property.
	 * @param params
	 *            Parameters needed by some messages. The messages with extra parameters are
	 *            formated according to {@link java.text.MessageFormat}specification
	 * @return String With the message
	 */
	public static String getMessage(String localeName, String messageName, Object params[])
	{
		return MessageFormat.format(((Properties) messagesMap.get(localeName)).getProperty(messageName), params);
	}

	/**
	 * @see #getMessage(String, String, Object[])
	 * @param messageName String
	 * @param params Object
	 * @return String
	 */
	public static String getMessage(String messageName, Object params[])
	{
		String lang = "";
		UserSession us = SessionFacade.getUserSession();

		if (us != null && us.getLang() != null) {
			lang = us.getLang();
		}

		if ("".equals(lang)) {
			return getMessage(defaultName, messageName, params);
		}

		return getMessage(lang, messageName, params);
	}
	
	public static String getMessage(String messageName, SimpleSequence params)
	{
		try {
			return getMessage(messageName, params.toList().toArray());
		}
		catch (Exception e) {
			throw new ForumException(e);
		}
	}

	/**
	 * Gets an I18N (internationalization) message.
	 * 
	 * @param m
	 *            The message name to retrieve. Must be a valid entry into the file specified by
	 *            <code>i18n.file property.
	 * @return String With the message
	 * @param localeName
	 *            String
	 */
	public static String getMessage(String localeName, String m)
	{
		if (!messagesMap.containsKey(localeName)) {
			load(localeName);
		}

		return (((Properties) messagesMap.get(localeName)).getProperty(m));
	}

	public static String getMessage(String m)
	{
		return getMessage(getUserLanguage(), m);
	}

	public static String getMessage(String m, UserSession us)
	{
		if (us == null || us.getLang() == null || us.getLang().equals("")) {
			return getMessage(defaultName, m);
		}

		return getMessage(us.getLang(), m);
	}

	/**
	 * Gets the language name for the current request. The method will first look at
	 * {@link UserSession#getLang()} and use it if any value is found. Otherwise, the default board
	 * language will be used
	 * 
	 * @return String
	 */
	public static String getUserLanguage()
	{
		UserSession us = SessionFacade.getUserSession();

		if (us == null || us.getLang() == null || us.getLang().trim().equals("")) {
			return defaultName;
		}

		return us.getLang();
	}

	/**
	 * Check whether the language is loaded in i18n.
	 * 
	 * @param language
	 *            String
	 * @return boolean
	 */
	public static boolean contains(String language)
	{
		return messagesMap.containsKey(language);
	}

	/**
	 * Check if the given language exist.
	 * 
	 * @param language
	 *            The language to check
	 * @return <code>true if the language is a valid and registered translation.
	 */
	public static boolean languageExists(String language)
	{
		return (localeNames.getProperty(language) != null);
	}
}