java 定时执行任务

import java.util.Timer;

import java.util.TimerTask;

import javax.servlet.ServletContext;

import javax.servlet.ServletContextEvent;

import javax.servlet.ServletContextListener;

public class ServletTimer implements ServletContextListener {

private Timer timer;

public void contextDestroyed(ServletContextEvent arg0) {//销毁定时器

timer.cancel();

System.out.println("定時器銷毀");

}

public void contextInitialized(ServletContextEvent event) {//启动定时器

timer = new java.util.Timer(true);

SampleTimer sampleTimer = new SampleTimer(event.getServletContext());

System.out.println("定时器启动");

timer.schedule(sampleTask, 0,60*60*1000);//一个小时执行一次

System.out.println("定时器完成");

}

}

任务类：

public class SampleTimer extends TimerTask {

private ServletContext context;

private static final int C_SCHEDULE_HOUR = 15;

private Timer timer;

public SampleTask(ServletContext context){

this.context = context;

}

@Override

public void run() {

System.out.print("dsdsd");

}

}

在web.xml中配置如下：

<listener>
<listener-class>com.*.*.ServletTimer </listener-class>
</listener>