defaulttimer.java

pos机交易实现源代码 含金融卡交易8583协议实现 开发环境：linux 典型应用：嵌入系统开发 仅供参考

/*
 * Copyright (c) 2000 jPOS.org.  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 acknowledgment:
 *    "This product includes software developed by the jPOS project 
 *    (http://www.jpos.org/)". Alternately, this acknowledgment may 
 *    appear in the software itself, if and wherever such third-party 
 *    acknowledgments normally appear.
 *
 * 4. The names "jPOS" and "jPOS.org" must not be used to endorse 
 *    or promote products derived from this software without prior 
 *    written permission. For written permission, please contact 
 *    [e-mail].
 *
 * 5. Products derived from this software may not be called "jPOS",
 *    nor may "jPOS" appear in their name, without prior written
 *    permission of the jPOS project.
 *
 * 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 JPOS PROJECT 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 jPOS Project.  For more
 * information please see <http://www.jpos.org/>.
 */

package org.jpos.util;

import java.util.*;

/**
 * Timer accesor singleton
 * @author Alejandro P. Revilla
 * @version $Id: DefaultTimer.java,v 1.1 2001/04/21 22:25:11 apr Exp $
 */

public class DefaultTimer {
    private static Timer defaultTimer = null;

    private DefaultTimer() { }

    public static Timer getTimer() {
        if (defaultTimer == null) {
            synchronized (DefaultTimer.class) {
                if (defaultTimer == null) 
                    defaultTimer = new Timer();
            }
        }
        return defaultTimer;
    }
}