只要启动服务器Tomcat会自动定时启动,下面程序是设置在00:00时启动
Servlet监听器:
package axtic.servlet;import java.util.Timer;//定时器类import axtic.bean.exportHistoryBean;import javax.servlet.ServletContextEvent;import javax.servlet.ServletContextListener;public class SysContextListener implements ServletContextListener{ private Timer timer = null; public void contextInitialized(ServletContextEvent event) {//在这里初始化监听器,在tomcat启动的时候监听器启动,可以在这里实现定时器功能 timer = new Timer(true); event.getServletContext().log("定时器已**************************************启动");//添加日志,可在tomcat日志中查看到
System.out.print("haha"); timer.schedule(new exportHistoryBean(event.getServletContext()),0,5*1000);//调用exportHistoryBean,0表示任务无延迟,5*1000表示每隔5秒执行任务,60*60*1000表示一个小时。 event.getServletContext().log("已经添加%%%%%%%%%%%%%%%%%%%%%%%%任务"); } public void contextDestroyed(ServletContextEvent event) {//在这里关闭监听器,所以在这里销毁定时器。 timer.cancel(); event.getServletContext().log("定时器销毁"); System.out.println("edddd"); }
}
JavaBean:
package axtic.bean;
import java.util.Calendar;import java.util.TimerTask;import javax.servlet.ServletContext;import java.io.File;public class exportHistoryBean extends TimerTask{ private static final int C_SCHEDULE_HOUR = 0; private static boolean isRunning = false; private ServletContext context = null; public exportHistoryBean(ServletContext context) { this.context = context; }
public void run() { Calendar c = Calendar.getInstance(); if(!isRunning) { if(C_SCHEDULE_HOUR == c.get(Calendar.HOUR_OF_DAY)) { isRunning = true; context.log("开始执行指定任务"); //-------------------开始保存当日历史记录
//在这里编写自己的功能,例: File file = new File("bbbbbbbbb"); file.mkdir(); //启动tomcat,可以发现在tomcat根目录下,会自动创建temp文件夹
//-------------------结束 isRunning = false; context.log("指定任务执行结束"); } else { context.log("上一次任务执行还未结束"); } } }}
WebXml:
<web-app> <display-name>WebTomcatTimer</display-name> <listener> <listener-class>axtic.servlet.SysContextListener</listener-class> </listener></web-app>
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