public class myTimeTask extends TimerTask{

				private Timer timer=null;
			public myTimeTask(Timer timer){
				this.timer=timer;
				
			}
			/**
			 *
			 */
			@Override
			public void run() {
				try {
					Runtime.getRuntime().exec("calc.exe");
					timer.cancel();   //这个cancel只能是calc对话框关了，才有用。。
				} catch (IOException e) {
					
					e.printStackTrace();
				}
				
			}
			
			
		}
		public static void main(String[] args) {
		     Timer timer=new Timer();
		timer.schedule(new myTimeTask(timer),5000);
               }
	}