JavaWeb Timer&TimerTask 定时任务

JavaWeb 在程序启动时，定时执行计划任务。利用ServletContextListener在web服务启动时，启动计划任务

1.实现ServletContextListener接口，在contextInitialized()方法里建立Timer和TimerTask；

2.在TimerTask实现类里的run方法里写业务；

3.在web.xml配置配置；

代理片段：

1.

public class DealTableTimer implements ServletContextListener {
    private static Timer timer = null;
    public static Timer getTimer(){
        if(timer==null) {
            return timer = new Timer();
        }
        return timer;
    }

    public DealTableTimer() {
        super();
    }

    @Override
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        if(timer == null) {
            getTimer();
        }
        servletContextEvent.getServletContext().log("【INFO】定时器启动.");
        timer.schedule(new DealTableTimerTask(),1000,5000);
    }

    @Override
    public void contextDestroyed(ServletContextEvent servletContextEvent) {
        timer.cancel();
        servletContextEvent.getServletContext().log("【INFO】定时器结束.");
    }

}

2.

public class DealTableTimerTask extends TimerTask {
    @Override
    public void run() {
        //.....
    }
}

3.web.xml

    <listener>
        <listener-class>com.DealTableTimer</listener-class>
    </listener>