关于定时运行的问题

Question

用Timer组件！可以定时执行动作！

Answer 1

请问能否说的详细一点?我就是没有看明白啊,Timer 和 TimerTask  谢谢

Answer 2

private java.util.Timer timer = null;
public void contextInitialized(ServletContextEvent event)
  {
        timer = new java.util.Timer(true);
        event.getServletContext().log("定时器已启动");
        timer.schedule(new MyTask(event.getServletContext()),0, 10*1000);
        event.getServletContext().log("已经添加任务调度表");
  }
public void contextDestroyed(ServletContextEvent event)
  {
    timer.cancel();
    event.getServletContext();log("定时器销毁");
   }------------------------------------------------------
public class MyTask extends TimerTask {
  private static final int C_SCHEDULE_HOUR = 22;
  private static boolean isRunning = false;
  private ServletContext context = null;  public MyTask(ServletContext context)
  {
          this.context = context;
  }  public void run()
  {
          Calendar cal = Calendar.getInstance();
          if (!isRunning)
          {
                  if (C_SCHEDULE_HOUR == cal.get(Calendar.HOUR_OF_DAY))
                  {
                          isRunning = true;
                          context.log("开始执行指定任务");                          //TODO添加自定义的详细任务，以下只是示例
                          int i = 0;
                          while (i++ < 10)
                          {
                                  context.log("已完成任务的" + i + "/" + 10);
                          }                          isRunning = false;
                          context.log("指定任务执行结束");
                  }
          }else {
                  context.log("上一次任务执行还未结束");
          }
  }
}

Answer 3

一个例子：
import java.uitl.*;
public class TimerTest{
public static void main(String args[]){
new TimerTest.do();}
void do(){
Timer t = new Timer(true);
t.schedule(new Task(),50000L);
}
}
class Task extends TimeTask{
public void run(){
System.out.println("This is task is running....");
} 
}