/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Copyright 2004 The Apache Software Foundation.

 *

 * Licensed 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.

 */

/*

 * $Id: Messages.java,v 1.1.4.1 2005/09/08 11:03:10 suresh_emailid Exp $

 */

package com.sun.org.apache.xml.internal.serializer.utils;

import java.util.ListResourceBundle;

import java.util.Locale;

import java.util.MissingResourceException;

import java.util.ResourceBundle;

/**

 * A utility class for issuing error messages.

 *

 * A user of this class normally would create a singleton

 * instance of this class, passing the name

 * of the message class on the constructor. For example:

 * <CODE>

 * static Messages x = new Messages("org.package.MyMessages");

 * </CODE>

 * Later the message is typically generated this way if there are no

 * substitution arguments:

 * <CODE>

 * String msg = x.createMessage(org.package.MyMessages.KEY_ONE, null);

 * </CODE>

 * If there are arguments substitutions then something like this:

 * <CODE>

 * String filename = ...;

 * String directory = ...;

 * String msg = x.createMessage(org.package.MyMessages.KEY_TWO,

 *   new Object[] {filename, directory) );

 * </CODE>

 *

 * The constructor of an instance of this class must be given

 * the class name of a class that extends java.util.ListResourceBundle

 * ("org.package.MyMessages" in the example above).

 * The name should not have any language suffix

 * which will be added automatically by this utility class.

 *

 * The message class ("org.package.MyMessages")

 * must define the abstract method getContents() that is

 * declared in its base class, for example:

 * <CODE>

 * public Object[][] getContents() {return contents;}

 * </CODE>

 *

 * It is suggested that the message class expose its

 * message keys like this:

 * <CODE>

 *   public static final String KEY_ONE = "KEY1";

 *   public static final String KEY_TWO = "KEY2";

 *   . . .

 * </CODE>

 * and used through their names (KEY_ONE ...) rather than

 * their values ("KEY1" ...).

 *

 * The field contents (returned by getContents()

 * should be initialized something like this:

 * <CODE>

 * public static final Object[][] contents = {

 * { KEY_ONE, "Something has gone wrong!" },

 * { KEY_TWO, "The file ''{0}'' does not exist in directory ''{1}''." },

 * . . .

 * { KEY_N, "Message N" }  }

 * </CODE>

 *

 * Where that section of code with the KEY to Message mappings

 * (where the message classes 'contents' field is initialized)

 * can have the Message strings translated in an alternate language

 * in a errorResourceClass with a language suffix.

 *

 *

 * This class is not a public API, it is only public because it is

 * used in com.sun.org.apache.xml.internal.serializer.

 *

 *  @xsl.usage internal

 */

public final class Messages

{

    /** The local object to use.  */

    private final Locale m_locale = Locale.getDefault();

    /** The language specific resource object for messages.  */

    private ListResourceBundle m_resourceBundle;

    /** The class name of the error message string table with no language suffix. */

    private String m_resourceBundleName;

    /**

     * Constructor.

     * @param resourceBundle the class name of the ListResourceBundle

     * that the instance of this class is associated with and will use when

     * creating messages.

     * The class name is without a language suffix. If the value passed

     * is null then loadResourceBundle(errorResourceClass) needs to be called

     * explicitly before any messages are created.

     *

     * @xsl.usage internal

     */

    Messages(String resourceBundle)

    {

        m_resourceBundleName = resourceBundle;

    }

    /**

     * Get the Locale object that is being used.

     *

     * @return non-null reference to Locale object.

     * @xsl.usage internal

     */

    private Locale getLocale()

    {

        return m_locale;

    }

    /**

     * Creates a message from the specified key and replacement

     * arguments, localized to the given locale.

     *

     * @param msgKey  The key for the message text.

     * @param args    The arguments to be used as replacement text

     * in the message created.

     *

     * @return The formatted message string.

     * @xsl.usage internal

     */

    public final String createMessage(String msgKey, Object args[])

    {

        if (m_resourceBundle == null)

        if (m_resourceBundle != null)

        {

            return createMsg(m_resourceBundle, msgKey, args);

        }

        else

            return "Could not load the resource bundles: "+ m_resourceBundleName;

    }

    /**

     * Creates a message from the specified key and replacement

     * arguments, localized to the given locale.

     *

     * @param errorCode The key for the message text.

     *

     * @param fResourceBundle The resource bundle to use.

     * @param msgKey  The message key to use.

     * @param args      The arguments to be used as replacement text

     *                  in the message created.

     *

     * @return The formatted message string.

     * @xsl.usage internal

     */

    private final String createMsg(

        ListResourceBundle fResourceBundle,

        String msgKey,

        Object args[]) //throws Exception

    {

        String fmsg = null;

        boolean throwex = false;

        String msg = null;

        if (msgKey != null)

            msg = fResourceBundle.getString(msgKey);

        else

            msgKey = "";

        if (msg == null)

        {

            throwex = true;

            /* The message is not in the bundle . . . this is bad,

             * so try to get the message that the message is not in the bundle

             */

            try

            {

                msg =

                    java.text.MessageFormat.format(

                        MsgKey.BAD_MSGKEY,

                        new Object[] { msgKey, m_resourceBundleName });

            }

            catch (Exception e)

            {

                /* even the message that the message is not in the bundle is

                 * not there ... this is really bad

                 */

                msg =

                    "The message key '"

                        + msgKey

                        + "' is not in the message class '"

                        + m_resourceBundleName+"'";

            }

        }

        else if (args != null)

        {

            try

            {

                // Do this to keep format from crying.

                // This is better than making a bunch of conditional

                // code all over the place.

                int n = args.length;

                for (int i = 0; i < n; i++)

                {

                    if (null == args[i])

                        args[i] = "";

                }

                fmsg = java.text.MessageFormat.format(msg, args);

                // if we get past the line above we have create the message ... hurray!

            }

            catch (Exception e)

            {

                throwex = true;

                try

                {

                    // Get the message that the format failed.

                    fmsg =

                        java.text.MessageFormat.format(

                            MsgKey.BAD_MSGFORMAT,

                            new Object[] { msgKey, m_resourceBundleName });

                    fmsg += " " + msg;

                }

                catch (Exception formatfailed)

                {

                    // We couldn't even get the message that the format of

                    // the message failed ... so fall back to English.

                    fmsg =

                        "The format of message '"

                            + msgKey

                            + "' in message class '"

                            + m_resourceBundleName

                            + "' failed.";

                }

            }

        }

        else

            fmsg = msg;

        if (throwex)

        {

            throw new RuntimeException(fmsg);

        }

        return fmsg;

    }

}