JAVA WEB程序中添加定时器
这是我的定时器类，用来定时执行某段任务；
package com.my.time;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Timer;
public class BugXmlTimer {
public Timer timer;
public void timerStart(){
timer = new Timer();
Date datetime=new Date();
Date midnightDate=new Date();
SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd");
SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
try {
midnightDate = sdf2.parse(sdf1.format(datetime)+" 23:00:00");
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
long in=midnightDate.getTime()-datetime.getTime();
System.out.println("before task");
//立刻执行，然后每隔30s执行一次
timer.schedule(new BugXmlTimerTask(), 0,30000);
}
public void timerStop(){
if(timer!=null)
timer.cancel();
}
public static void main(String[] args){
BugXmlTimer myTimer=new BugXmlTimer();
// TODO Auto-generated method stub
myTimer.timerStart();
}
}
//这是执行任务的类，即每隔一段时间要做的事情在这里
package com.my.time;
import java.util.TimerTask;
public class BugXmlTimerTask extends TimerTask {
@Override
public void run() {
System.out.print("run task");
}
}
//以下是出发定时操作的类，该类实现了ServletContextListener
public class MyTimerListener implements ServletContextListener {
private BugXmlTimer mytimer = new BugXmlTimer ();
public void contextInitialized(ServletContextEvent event) {
mytimer.timerStart();
}
public void contextDestroyed(ServletContextEvent event) {
mytimer.timerStop();
}
}
然后在web.xml里部署一下，即可在程序启动后运行定时器了！
<listener>
<listener-class>com.my.time.MyTimerListener </listener-class>
</listener>
补充：Jsp教程,J2EE/EJB/服务器 
