messages.java

开发MySql数据库的最新JDBC驱动。

/*
 Copyright (C) 2002-2004 MySQL AB

 This program is free software; you can redistribute it and/or modify
 it under the terms of version 2 of the GNU General Public License as 
 published by the Free Software Foundation.

 There are special exceptions to the terms and conditions of the GPL 
 as it is applied to this software. View the full text of the 
 exception in file EXCEPTIONS-CONNECTOR-J in the directory of this 
 software distribution.

 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA



 */
package com.mysql.jdbc;

import java.text.MessageFormat;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;

/**
 * Support for localized messages.
 * 
 * @author Mark Matthews
 * @version $Id: Messages.java 3726 2005-05-19 15:52:24Z mmatthews $
 */
public class Messages {

	private static final String BUNDLE_NAME = "com.mysql.jdbc.LocalizedErrorMessages"; //$NON-NLS-1$

	private static final ResourceBundle RESOURCE_BUNDLE;

	static {
		ResourceBundle temp = null;

		//
		// Overly-pedantic here, some appserver and JVM combos don't deal
		// well with the no-args version, others don't deal well with
		// the three-arg version, so we need to try both :(
		//

		try {
			temp = ResourceBundle.getBundle(BUNDLE_NAME, Locale.getDefault(),
					Messages.class.getClassLoader());
		} catch (Throwable t) {
			try {
				temp = ResourceBundle.getBundle(BUNDLE_NAME);
			} catch (Throwable t2) {
				throw new RuntimeException(
						"Can't load resource bundle due to underlying exception "
								+ t.toString());
			}
		} finally {
			RESOURCE_BUNDLE = temp;
		}
	}

	/**
	 * Returns the localized message for the given message key
	 * 
	 * @param key
	 *            the message key
	 * @return The localized message for the key
	 */
	public static String getString(String key) {
		if (RESOURCE_BUNDLE == null) {
			throw new RuntimeException(
					"Localized messages from resource bundle '" + BUNDLE_NAME
							+ "' not loaded during initialization of driver.");
		}

		try {
			if (key == null) {
				throw new IllegalArgumentException(
						"Message key can not be null");
			}

			String message = RESOURCE_BUNDLE.getString(key);

			if (message == null) {
				message = "Missing error message for key '" + key + "'";
			}

			return message;
		} catch (MissingResourceException e) {
			return '!' + key + '!';
		}
	}

	public static String getString(String key, Object[] args) {
		return MessageFormat.format(getString(key), args);
	}

	/**
	 * Dis-allow construction ...
	 */
	private Messages() {

		// XXX Auto-generated constructor stub
	}
}