java时钟

package Clock;
public class Clock{
   private int hour ;
   private int minute ;
   private int second ;
    
// private Display H = new Display(hour,24) ;
// private Display M = new Display(minute,60) ;
// private Display S = new Display(second,60) ;
    
   public Clock(int hour , int minute , int second ) {
       this.hour = hour ;
       this.minute = minute ;
       this.second = second ;
   }
   public void tick() {
        Display S = new Display(second,60) ;
        Display M = new Display(minute,60) ;
        Display H = new Display(hour,24) ;
        for(;;) { 
        S.increase() ;
        this.second = S.getvalue() ;
        if (S.getvalue() == 0) {
             M.increase() ;
             this.minute = M.getvalue() ;
             if(M.getvalue() == 0) {
                 H.increase() ;
                 this.hour = H.getvalue() ;
             }
          }
        }
   } 

   public String toString() {
       String res ;
       String a1 = Integer.toString(hour) ;
       String a2 = Integer.toString(minute) ;
       String a3 = Integer.toString(second) ;
       if (hour < 10) {
           a1  = "0" + a1 ;
       }
       if (minute < 10){
           a2  = "0" + a2 ;
       }
       if(second < 10) {
           a3  = "0" + a3 ;
       }
       res = a1 + ":" + a2 + ":" + a3 ;
       return res ;
   }
    

public static void main(String[] args) {
     
     
    java.util.Scanner in = new java.util.Scanner(System.in);

    Clock clock = new Clock(in.nextInt(),in.nextInt(),in.nextInt());

    clock.tick();

    System.out.print(clock);

    in.close();

}
}