java重置Timer執行頻率

public class BallUtil {
    public static  Timer fisTimer ;
    
    public static void fisStartBall(){
        long firstTime = 2000l;
        long time = 2000l;
        if(fisTimer==null){
            fisTimer = new Timer();
        }
        fisTimer.scheduleAtFixedRate(new TimerTask(){
            public void run(){
                System.out.println("time="+time+"-----firstTime="+"定時器執行"+"----type="+type);
                Date date = new Date();
                int hour = date.getHours();
                if(hour==9){
                        System.out.println("重置頻率");
                        stop();//關閉后再開啟
                        start();
                        //直接更新新的時間
                        //Long newTime = patt.getInt("INTERVDAY")*60l*1000;
                        //resetPeriod(newTime);
                }
            }
            //此方法也可以重置頻率，直接傳入新的時間
            public void resetPeriod(final long time) throws IllegalArgumentException, IllegalAccessException{
                Field[] fields = this.getClass().getSuperclass() .getDeclaredFields();  
                   for (Field field : fields)  
                   {  
                       if (field.getName().endsWith("period"))  
                       {  
                           if (!field.isAccessible())  
                           {  
                               field.setAccessible(true);  
                           }  
                           field.set(this, time);  
                       }  
                   }  
            }
        }, firstTime, time);
    }
    public  static void start(){
            fisStartBall();
    }
    
    public static void stop(){
            fisTimer.cancel();
    }
}