关于侦听器和计时器实现定时采集信息的功能，定时器未能正常启动。

我写了一个servlet实现这个功能，但是在启动程序的时候好像定时器没启动帮我看下哪里错了。

 package sxdd.gps.maininfo;

import javax.servlet.ServletContextEvent;



public class MyTimer extends javax.servlet.http.HttpServlet implements javax.servlet.ServletContextListener {

    private java.util.Timer timer = null;

    public void contextInitialized(ServletContextEvent event) {
        timer = new java.util.Timer(true);
        event.getServletContext().log("定时器已启动"); 
        System.out.println("定时器已启动");
        timer.schedule(new MyTimerTask(),0,3*1000);
        event.getServletContext().log("已经添加任务调度表");
        System.out.println("已经添加任务调度表");
    }

    public void contextDestroyed(ServletContextEvent event) {

        timer.cancel();
         event.getServletContext().log("定时器销毁");
        System.out.println("定时器销毁");
    }
}


package sxdd.gps.maininfo;

import java.util.Calendar;
import java.util.TimerTask;

import javax.servlet.ServletContext;


public class MyTimerTask extends TimerTask {

    private static boolean isRunning = false;
    private ServletContext context = null;

     public void StatisticsTask(ServletContext context)
        {
            this.context = context;
        }

    @Override
    public void run(){

        if(!isRunning){

            isRunning = true;
            //需要实现的功能的代码
            System.out.println("++++++++++++++++++++++++++++++");
            //任务结束
            isRunning = false;
        }else{
             context.log("上一次任务执行还未结束");
        }
    }
}


<listener>
　　　　        <listener-class>sxdd.gps.maininfo.MyTimer</listener-class>
　　  </listener>

timer = new java.util.Timer(true); 如果没有记错；需要.run();这样一样东西；
timer = new java.util.Timer().run();