/*
 * $Header: /home/cvs/jakarta-tomcat-4.0/jasper/src/share/org/apache/jasper/util/StringManager.java,v 1.1 2000/08/12 00:52:15 pierred Exp $
 * $Revision: 1.1 $
 * $Date: 2000/08/12 00:52:15 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  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. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR
 * ITS 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 software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * [Additional notices, if required by prior licensing conditions]
 *
 */ 


package org.apache.jasper.util;

import java.text.MessageFormat;
import java.util.*;

/**
 * An internationalization / localization helper class which reduces
 * the bother of handling ResourceBundles and takes care of the
 * common cases of message formating which otherwise require the
 * creation of Object arrays and such.
 *
 * <p>The StringManager operates on a package basis. One StringManager
 * per package can be created and accessed via the getManager method
 * call.
 *
 * <p>The StringManager will look for a ResourceBundle named by
 * the package name given plus the suffix of "LocalStrings". In
 * practice, this means that the localized information will be contained
 * in a LocalStrings.properties file located in the package
 * directory of the classpath.
 *
 * <p>Please see the documentation for java.util.ResourceBundle for
 * more information.
 *
 * @author James Duncan Davidson [duncan@eng.sun.com]
 * @author James Todd [gonzo@eng.sun.com]
 */

public class StringManager {

    /**
     * The ResourceBundle for this StringManager.
     */

    private ResourceBundle bundle;

    /**
     * Creates a new StringManager for a given package. This is a
     * private method and all access to it is arbitrated by the
     * static getManager method call so that only one StringManager
     * per package will be created.
     *
     * @param packageName Name of package to create StringManager for.
     */

    private StringManager(String packageName) {
        String bundleName = packageName + ".LocalStrings";
        bundle = ResourceBundle.getBundle(bundleName);
    }

    private StringManager(String packageName,Locale loc) {
        String bundleName = packageName + ".LocalStrings";
        bundle = ResourceBundle.getBundle(bundleName,loc);
    }

    /**
     * Get a string from the underlying resource bundle.
     *
     * @param key
     */

    public String getString(String key) {
        if (key == null) {
            String msg = "key is null";

            throw new NullPointerException(msg);
        }

        String str = null;

        try {
	    str = bundle.getString(key);
        } catch (MissingResourceException mre) {
            str = "[cannot find message associated with key '" + key + "' due to " + mre + "]";
	    // mre. print Stack Trace();
        }

        return str;
    }

    /**
     * Get a string from the underlying resource bundle and format
     * it with the given set of arguments.
     *
     * @param key
     * @param args
     */

    public String getString(String key, Object[] args) {
	      String iString = null;
        String value = getString(key);

	// this check for the runtime exception is some pre 1.1.6
	// VM's don't do an automatic toString() on the passed in
	// objects and barf out

	try {
            // ensure the arguments are not null so pre 1.2 VM's don't barf
            Object nonNullArgs[] = args;
            for (int i=0; i<args.length; i++) {
		if (args[i] == null) {
		    if (nonNullArgs==args) nonNullArgs=(Object[])args.clone();
		    nonNullArgs[i] = "null";
		}
	    }

            iString = MessageFormat.format(value, nonNullArgs);
	} catch (IllegalArgumentException iae) {
	    StringBuffer buf = new StringBuffer();
	    buf.append(value);
	    for (int i = 0; i < args.length; i++) {
		buf.append(" arg[" + i + "]=" + args[i]);
	    }
	    iString = buf.toString();
	}
	return iString;
    }

    /**
     * Get a string from the underlying resource bundle and format it
     * with the given object argument. This argument can of course be
     * a String object.
     *
     * @param key
     * @param arg
     */

    public String getString(String key, Object arg) {
	Object[] args = new Object[] {arg};
	return getString(key, args);
    }

    /**
     * Get a string from the underlying resource bundle and format it
     * with the given object arguments. These arguments can of course
     * be String objects.
     *
     * @param key
     * @param arg1
     * @param arg2
     */

    public String getString(String key, Object arg1, Object arg2) {
	Object[] args = new Object[] {arg1, arg2};
	return getString(key, args);
    }
    
    /**
     * Get a string from the underlying resource bundle and format it
     * with the given object arguments. These arguments can of course
     * be String objects.
     *
     * @param key
     * @param arg1
     * @param arg2
     * @param arg3
     */

    public String getString(String key, Object arg1, Object arg2,
			    Object arg3) {
	Object[] args = new Object[] {arg1, arg2, arg3};
	return getString(key, args);
    }

    /**
     * Get a string from the underlying resource bundle and format it
     * with the given object arguments. These arguments can of course
     * be String objects.
     *
     * @param key
     * @param arg1
     * @param arg2
     * @param arg3
     * @param arg4
     */

    public String getString(String key, Object arg1, Object arg2,
			    Object arg3, Object arg4) {
	Object[] args = new Object[] {arg1, arg2, arg3, arg4};
	return getString(key, args);
    }
    // --------------------------------------------------------------
    // STATIC SUPPORT METHODS
    // --------------------------------------------------------------

    private static Hashtable managers = new Hashtable();

    /**
     * Get the StringManager for a particular package. If a manager for
     * a package already exists, it will be reused, else a new
     * StringManager will be created and returned.
     *
     * @param packageName
     */

    public synchronized static StringManager getManager(String packageName) {
      StringManager mgr = (StringManager)managers.get(packageName);
      if (mgr == null) {
          mgr = new StringManager(packageName);
          managers.put(packageName, mgr);
      }
      return mgr;
    }
     /**
     * Get the StringManager for a particular package and Locale. If a manager for
     * a package already exists, it will be reused, else a new
     * StringManager will be created for that Locale and returned.
     *
     *
     * @param packageName
     */

   public synchronized static StringManager getManager(String packageName,Locale loc) {
      StringManager mgr = (StringManager)managers.get(packageName+"_"+loc.toString());
      if (mgr == null) {
          mgr = new StringManager(packageName,loc);
          managers.put(packageName+"_"+loc.toString(), mgr);
      }
      return mgr;
    }

}
