source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/util/Dictionary.java@ 26257

/*
 *    Dictionary.java
 *    Copyright (C) 2005 New Zealand Digital Library, http://www.nzdl.org
 *
 *    This program 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 of the License, or
 *    (at your option) any later version.
 *
 *    This program 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 this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package org.greenstone.gsdl3.util;

import java.util.ResourceBundle;
import java.util.Locale;
import java.util.Enumeration;

import org.apache.log4j.*;

public class Dictionary
{

    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.util.Dictionary.class.getName());

    /** The locale of this dictionary. */
    protected Locale locale = null;

    /** The resource that has been loaded */
    protected String resource = null;

    /**
     * The ResourceBundle which contains the raw key-value mappings. Loaded from
     * a file named "resource_locale.properties
     */
    private ResourceBundle raw = null;

    /**
     * Constructs the Dictionary class by first creating a locale from the
     * specified language, (or using the default locale if this didn't work),
     * then loading a resource bundle based on this locale.
     */
    public Dictionary(String resource, String lang)
    {
        // Initialize.

        this.locale = new Locale(lang);
        this.resource = resource;
        if (this.locale == null)
        {
            this.locale = Locale.getDefault();
        }
        try
        {
            this.raw = ResourceBundle.getBundle(this.resource, this.locale);
        }
        catch (Exception e)
        {
            //logger.debug("Dictionary: couldn't locate a resource bundle for "+resource);
        }
    }

    public Dictionary(String resource, Locale locale)
    {
        this.locale = locale;
        this.resource = resource;
        try
        {
            this.raw = ResourceBundle.getBundle(this.resource, this.locale);
        }
        catch (Exception e)
        {
            //logger.debug("Dictionary: couldn't locate a resource bundle for "+resource);
        }
    }

    /**
     * Constructs the Dictionary class by first creating a locale from the
     * specified language, (or using the default locale if this didn't work),
     * then loading a resource bundle based on this locale. A classloader is
     * specified which can be used to find the resource.
     */
    public Dictionary(String resource, String lang, ClassLoader loader)
    {
        // Initialize.
        this.locale = new Locale(lang);
        this.resource = resource;
        if (this.locale == null)
        {
            this.locale = Locale.getDefault();
        }
        // try the specified class loader
        try
        {
            this.raw = ResourceBundle.getBundle(this.resource, this.locale, loader);
            return;
        }
        catch (Exception e)
        {
        }
        ;

        try
        {
            this.raw = ResourceBundle.getBundle(this.resource, this.locale);
        }
        catch (Exception ex)
        {
            //logger.debug("Dictionary: couldn't locate a resource bundle for "+resource);
        }
    }

    public Enumeration getKeys()
    {
        if (this.raw != null)
        {
            return this.raw.getKeys();
        }
        return null;
    }

    /**
     * Overloaded to call get with both a key and an empty argument array.
     * 
     * @param key
     *            A <strong>String</strong> which is mapped to a initial String
     *            within the ResourceBundle.
     * @return A <strong>String</strong> which has been referenced by the key
     *         String and that contains no argument fields.
     */
    public String get(String key)
    {
        return get(key, null);
    }

    /**
     * Used to retrieve a property value from the Locale specific
     * ResourceBundle, based upon the key and arguments supplied. If the key
     * cannot be found or if some other part of the call fails a default
     * (English) error message is returned. <BR>
     * Here the get recieves a second argument which is an array of Strings used
     * to populate argument fields, denoted {<I>n</I>}, within the value String
     * returned.
     * 
     * @param key
     *            A <strong>String</strong> which is mapped to a initial String
     *            within the ResourceBundle.
     * @param args
     *            A <strong>String[]</strong> used to populate argument fields
     *            within the complete String.
     * @return A <strong>String</strong> which has been referenced by the key
     *         String and that either contains no argument fields, or has had
     *         the argument fields populated with argument Strings provided in
     *         the get call.
     */
    public String get(String key, String args[])
    {
        String argsStr = "";
        if (args != null)
        {
            for (String arg : args)
            {
                argsStr += arg + " ";
            }
        }

        if (this.raw == null)
        {
            return null;
        }
        try
        {
            String initial_raw = this.raw.getString(key);
            // convert to unicode, copied from gatherer dictionary
            String initial = new String(initial_raw.getBytes("ISO-8859-1"), "UTF-8");

            // if we haven't been given any args, don't bother looking for them
            if (args == null)
            {
                return initial;
            }
            // If the string contains arguments we have to insert them.
            StringBuffer complete = new StringBuffer();
            // While we still have initial string left.
            while (initial.length() > 0 && initial.indexOf('{') != -1 && initial.indexOf('}') != -1)
            {
                // Remove preamble
                int opening = initial.indexOf('{');
                int closing = initial.indexOf('}');
                int comment_mark = initial.indexOf('-', opening); // May not exist
                if (comment_mark > closing)
                { // May also be detecting a later comment
                    comment_mark = -1;
                }
                complete.append(initial.substring(0, opening));

                // Parse arg_num
                String arg_str = null;
                if (comment_mark != -1)
                {
                    arg_str = initial.substring(opening + 1, comment_mark);
                }
                else
                {
                    arg_str = initial.substring(opening + 1, closing);
                }
                if (closing + 1 < initial.length())
                {
                    initial = initial.substring(closing + 1);
                }
                else
                {
                    initial = "";
                }
                int arg_num = Integer.parseInt(arg_str);
                // Insert argument
                if (args != null && 0 <= arg_num && arg_num < args.length)
                {
                    complete.append(args[arg_num]);
                }
            }
            complete.append(initial);
            return complete.toString();
        }
        catch (Exception e)
        {
            //logger.debug("Dictionary Error: couldn't find string for key:" + key +" in resource "+this.resource);
            return null;
        }
    }
}