package com.ripsoft.util;

import java.util.Calendar;

import java.util.Timer;

import javax.servlet.ServletContextEvent;

import javax.servlet.ServletContextListener;

public class TimerListener implements ServletContextListener{

private Timer timer = null;

@Override

public void contextInitialized(ServletContextEvent event) {

timer = new Timer(true);

event.getServletContext().log(“定时器已启动”);

//设置执行时间

Calendar calendar = Calendar.getInstance();

int year = calendar.get(Calendar.YEAR);

int month = calendar.get(Calendar.MONTH);

int day = calendar.get(Calendar.DAY_OF_MONTH);//每天

//定制每天的11:00:00执行

calendar.set(year, month, day, 11, 00, 00);

java.util.Date date = calendar.getTime();

int period = 30 * 1000;

//每天的date时刻执行TestTask，每隔30秒重复执行

timer.schedule(new TestTask(), date, period);

//每天的date时刻执行TestTask, 仅执行一次

//timer.schedule(new TestTask(), date);

}

@Override

public void contextDestroyed(ServletContextEvent event) {

if (timer != null) {

timer.cancel();

event.getServletContext().log(“定时器销毁”);

}

}

}

package com.ripsoft.util;

import java.util.TimerTask;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

public class TestTask extends TimerTask{

protected final Log logger = LogFactory.getLog(getClass());

private static boolean isRunning = false;

@Override

public void run() {

if (!isRunning) {

isRunning = true;

logger.info(“开始执行任务。”);

int i = 0;

while (i++ < 10) {

logger.info(“已完成任务的” + i + “/” + 10);

}

isRunning = false;

logger.info(“任务执行结束。”);

} else {

logger.info(“上一次任务执行还未结束，本次任务不能执行。”);

}

}

}

1.TestTimerListener.java执行定时任务，实现servlet的ServletContextListener接口，当服务器启动时开始执行TestTask任务

2.想要任务在服务器启动时定时执行，就要借助监听实现需要在web.xml中做如下配置

com.ripsoft.util.TimerListener