import java.util.TimerTask;
public class TimerTaskTest extends TimerTask{
  @Override  
  public void run() {  
     // TODO Auto-generated method stub  
     System.out.println("执行任务……");  
  } 
}

import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
public class TestTimer {
  public static void main(String[] args){  
       Timer timer = new Timer();  
       Calendar calendar = Calendar.getInstance();
       calendar.set(Calendar.HOUR_OF_DAY, 12);//控制小时
       calendar.set(Calendar.MINUTE, 0);//控制分钟
       calendar.set(Calendar.SECOND, 0);//控制秒
       Date time = calendar.getTime();//执行任务时间为12:00:00
       //每天定时12:00执行操作，每秒执行一次
       timer.schedule(new TimerTaskTest(), time, 1000 );  
    }  
}