main(){
   timer t1 = new timer(10);
   System.out.println("123");
}

class timer{
    public timer(int seconds)//每隔seconds秒运行一次,a是调度算法选择 
    {
        // Create local timer
        localTimer = new Timer();
        
        // Create local timer task and set the timer-parameter
        localTimer.schedule(new Dispacther(p,a), 0 , seconds * 1000); 
    }
    
    class Dispacther extends TimerTask{
        public Dispacther(int p,int a){

        }
 
        public void run(){
           localTimer.cancle();//比如在这里取消了任务,怎么再执行main中的输出123?
        }

    } 
}

Timer timer=new Timer();
  timer.schedule(new TimerTask(){
      public void run(){
        System.out.println("我是定时器");
        timer.cancel();
      }
  ,1000}
timer.cancel();
System.out.println("123");