JAVA执行定时脚本

Web工程实现执行定时脚本主要是利用Servlet在启动的时候被载入，使用java.util.Timer来实现；

1.建立一个Web工程(AutoScript);
2.建立一个com.wangwz.autoscript.AutoTimerTask类;内容如下:
    package com.wangwz.autoscript;

    import java.text.SimpleDateFormat;
    import java.util.Date;
    import java.util.TimerTask;

    public class AutoTimerTask extends TimerTask
    {
        public void run()
        {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
            System.out.println(sdf.format(new Date()) + "   I am running");
        }
    }
3.建立com.wangwz.autoscript.AutoScript.java
    package com.wangwz.autoscript;

    import java.io.IOException;
    import java.io.PrintWriter;
    import java.util.Date;
    import java.util.Timer;

    import javax.servlet.ServletContext;
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;

    public class AutoScript extends HttpServlet
    {
        private static final long serialVersionUID = 1L;

        private Timer printTimer = null;

        private AutoTimerTask autoTimerTask = null;

        public AutoScript()
        {
            super();
        }

        public void destroy()
        {
            System.out.println("YYYYYYYYYYYYYYY");
            super.destroy();
            if (this.printTimer != null)// 在Servlet停止的时候，关闭掉线程
                this.printTimer.cancel();
        }

        public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
        {
            response.setContentType("text/html");
            PrintWriter out = response.getWriter();
            out.flush();
            out.close();
        }

        public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
        {
            doGet(request, response);
        }

        public void init() throws ServletException
        {
            System.out.println("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX");
            try
            {
                ServletContext sc = this.getServletContext();
                String s = sc.getInitParameter("printtime");
                printTimer = new Timer();
                autoTimerTask = new AutoTimerTask();
                Date doTime = new Date();
                Date nowTime = new Date();
                long timestamp = Long.parseLong(s);

                doTime.setHours(13);
                doTime.setMinutes(30);
                if (nowTime.after(doTime))// 当前已经超过指定时间，刚设置到明天的13：30分执行
                {
                    doTime.setDate(doTime.getDate() + 1);
                }

               // 启动printTimer线程；执行的内容为printTimerTask；date为第一次执行时间；每隔timestamp再次执行一次
                printTimer.schedule(autoTimerTask, doTime, timestamp);
            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
        }
    }
4.在web.xml中插入如下内容:
    <servlet>
        <servlet-name>AutoScript</servlet-name>
        <servlet-class>com.wangwz.autoscript.AutoScript</servlet-class>
        <load-on-startup>4</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>AutoScript</servlet-name>
        <url-pattern>/AutoScript</url-pattern>
    </servlet-mapping>
    <context-param>
        <param-name>printtime</param-name>
        <param-value>60000</param-value><!--毫秒为单位,此为1分钟-->
    </context-param>

注:如果不是web工程，而是普通的JAVA工程，那么可以在JAVA类里面直接写Timer.schedule(TimerTask, doTime, timestamp);

我尝试过"实现ServletContextListener接口,在web.xml中配置这个监听器"，不过出了如下问题：
Tomcat+window下面正常；Resin+Linux下面不正常(当Resin中装多个工程时,每个工程都会经过这个监听器,因此会生成多个Timer)
不知道是否是我处理得有问题,如你有什么高见,请留言相教！