Java定时任务

通过监听器（Listener）和定时器（Timer）定时执行某个任务（Task）。

(1)Listener

<!---->import java.util.Timer;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public   class MyListener implements ServletContextListener {
  private Timer timer =   null ;

  public   void contextInitialized(ServletContextEvent event) {
    timer =   new Timer( true );
    timer.schedule( new MyTask(), 0 , 86400000 ); // milliseconds
  }

  public   void contextDestroyed(ServletContextEvent event) {
    timer.cancel();
  }
}

(2)Task

<!---->import java.util.TimerTask;
public   class MyTask extends TimerTask {
public   void run() {
System.out.println(( new Date()));
  }
}

(3)web.xml配置

<!---->< listener >
< listener - class > com.fastunit.samples.listener.MyListener </ listener - class >
</ listener >