Date计算人活了多少天

package livedate;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;
public class Livedate {
    public static void main(String[] args) throws ParseException {
        System.out.println("please release your birthdate:yyyy-MM-dd");
        Scanner sc=new Scanner(System.in);
        String birthdate=sc.next();
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
        Date birthday=sdf.parse(birthdate);
        Long birthdaySecond=birthday.getTime();

            System.out.println(birthday);
            Date dateC=new Date();
            Long Currentsecond=dateC.getTime();
            if(birthdaySecond>Currentsecond){
                System.out.println("no ret");
            }else {
                Long secondday = Currentsecond - birthdaySecond;
                int day = (int) (secondday / (60 * 1000 * 60 * 24));
                System.out.println(day);
            }



    }
}