web应用每晚12点定时执行程序代码实例

1、当前web应用的web.xml文件配置容器监听类com.isoftstone.zfmi.listen.ZfmiContextListener：

-------------------------------------------------------------------------------------

  
    com.isoftstone.zfmi.listen.ZfmiContextListener
  

-------------------------------------------------------------------------------------

在后，元素之前

2、容器监听类com.isoftstone.zfmi.listen.ZfmiContextListener

在应用初始化和结束时，分别执行其覆盖的contextInitialized() 和contextDestroyed()方法，在contextInitialized()方法里，通过定时器timer的schedule(new FinDataTimerTask(),operTime, 86400000)方法在指定时间反复执行 FinDataTimerTask()对象中run()方法的操作，operTime 为指定初次执行时间，86400000)为反复执行时间间隔毫秒数，当前设定为一天，调试时可设短。

ZfmiContextListener.java:

-------------------------------------------------------------------------------------

package com.isoftstone.zfmi.listen;

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

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;

import org.apache.log4j.Logger;

public class ZfmiContextListener extends HttpServlet implements
   ServletContextListener {
Logger log = Logger.getLogger(this.getClass());
Timer timer = new Timer();

Date operTime;
public void service(ServletRequest request, ServletResponse response)
    throws ServletException, IOException {//

}

public void contextInitialized(ServletContextEvent sce) {
   log.info("\n 执行应用监听器初始方法      initialcontext....");
  
   Calendar now=Calendar.getInstance();
   now.add(Calendar.DATE, 1);
   now.set(Calendar.HOUR_OF_DAY, 0);
   now.set(Calendar.MINUTE, 0);
   now.set(Calendar.SECOND, 0);
   now.set(Calendar.MILLISECOND, 0);
   log.info("\n时间now为：   "+now.toString()+"     毫秒数："+now.getTimeInMillis());
   operTime=new Date(now.getTimeInMillis());
   log.info("\n预设初始执行时间为：   "+operTime);
   timer.schedule(new FinDataTimerTask(),operTime, 86400000); //一天执行一次
//   timer.schedule(new FinDataTimerTask(),operTime, 10000);   //10秒钟执行一次,调试可用
}

public void contextDestroyed(ServletContextEvent sce) {
   log.info("\n 执行应用监听器结束方法       destory context....");
   timer.cancel();
}
}

-------------------------------------------------------------------------------------

3、定时任务类com.isoftstone.zfmi.listen.FinDataTimerTask

继承TimerTask，需要定时执行的操作写在其覆盖的run()方法里面

FinDataTimerTask.java:

-------------------------------------------------------------------------------------

package com.isoftstone.zfmi.listen;

import java.util.TimerTask;

import org.apache.log4j.Logger;

public class FinDataTimerTask extends TimerTask {
Logger log = Logger.getLogger(this.getClass());

public void run() {
   //定时进行的操作
   log.info("\n时间到，正在执行定时预设的操作....");
  
}
}

-------------------------------------------------------------------------------------