java Timer-优快云博客

本文介绍了一个使用Java实现的定时任务调度示例。通过继承TimerTask并重写run()方法定义任务内容，利用Timer类来安排任务的执行时机。该示例展示了如何设置任务在特定时间点执行，以及如何在应用启动和关闭时启动和取消这些任务。

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package com.test.task;

import java.util.Date;
import java.util.TimerTask;

public class MyTask extends TimerTask {

	@Override
	public void run() {
		System.out.println("call at " + (new Date()));


	}

}

package com.test.task;

import java.util.Calendar;
import java.util.Date;
import java.util.Timer;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

/**
 * Application Lifecycle Listener implementation class MyListener
 *
 */
public class MyListener implements ServletContextListener {
	private Timer timer = null;

    /**
     * Default constructor. 
     */
    public MyListener() {
        // TODO Auto-generated constructor stub
    }

	/**
     * @see ServletContextListener#contextInitialized(ServletContextEvent)
     */
    public void contextInitialized(ServletContextEvent arg0) {
        // TODO Auto-generated method stub
    	timer = new Timer(true);
    	// repeat invoke the task
       // timer.schedule(new MyTask(), 0,5*1000); 
        
      //Get the Date corresponding to 11:01:00 pm today.
      // task will invoke in 11:58
    	Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.HOUR_OF_DAY, 11);
        calendar.set(Calendar.MINUTE, 58);
        calendar.set(Calendar.SECOND, 0);
        Date time = calendar.getTime();
        
        Calendar calendar1 = Calendar.getInstance();
        calendar.set(Calendar.HOUR_OF_DAY, 11);
        calendar.set(Calendar.MINUTE, 57);
        calendar.set(Calendar.SECOND, 0);
        Date time1 = calendar.getTime();
        
        timer = new Timer();
        timer.schedule(new MyTask(), time);
        timer.schedule(new MyTask(), time1);


    }

	/**
     * @see ServletContextListener#contextDestroyed(ServletContextEvent)
     */
    public void contextDestroyed(ServletContextEvent arg0) {
        // TODO Auto-generated method stub
    	timer.cancel();

    }
	
}

  <listener>
    <listener-class>com.test.task.MyListener</listener-class>
  </listener>

http://bakcom.iteye.com/blog/1618721