package com.utils;import java.io.IOException;import java.text.SimpleDateFormat;import java.util.Date;
public class MyTimer extends Thread {        // 间隔时间：小时    private int intervalHours;        // 误差(操作所需时间可能导致误差)：分钟    private int deviationMinute;        // 执行时间    private String runTime;        public MyTimer(){        // 参数取得        intervalHours = 24;        deviationMinute = 5;        runTime= "19:30";    }        public void run() {        while (!this.isInterrupted()) {// 线程未中断执行循环                    // 获取当前时间：HH:mm            Date now = new Date();             SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm");            String hours = dateFormat.format(now);             // 时间到达            if(hours.equals(runTime)){                doRun();                try {                    // 长时间休眠:间隔时间-误差                    Thread.sleep(intervalHours * 3600 * 1000 - deviationMinute * 60 * 1000);                } catch (InterruptedException e) {                    e.printStackTrace();                }            }else{                try {                    // 等待间隔:30s                    Thread.sleep(30000);                    System.out.println(hours);                } catch (InterruptedException e) {                    e.printStackTrace();                }            }        }    }    /**     * 处理     */    private void doRun() {    }}

package com.utils;import javax.servlet.http.HttpServlet;public class MyServlet extends HttpServlet{    /**     *      */    private static final long serialVersionUID = 1L;    private MyTimer myTimer;      public MyServlet(){          }      public void init(){          String str = null;          if (str == null && myTimer== null) {              myTimer=  new MyTimer();                        myTimer.start();         }
　　　　　super.init();      }      public void destory(){          if (myTimer!= null && myTimer.isInterrupted()) {              myTimer.interrupt();          }
　　　　　super.destroy();      }  }

    <servlet>        <servlet-name>MyServlet</servlet-name>        <servlet-class>com.utils.MyServlet</servlet-class>        <load-on-startup>9</load-on-startup
　　</servlet>