如何使用Java计算生日的剩余天数[副本]

Question

我想用Java计算生日的剩余天数。如果今天的日期等于输入的日期，我日志今天是我的生日。如果今天的日期不等于输入的日期，我要计算生日的剩余天数。我怎么能那样做？

我的代码：

public class BirthdayCountdown {

    public static void bdayCounter(String bday) throws Exception {
        SimpleDateFormat formatter= new SimpleDateFormat("dd-MM-yyyy");
        Date today = new Date();
        Date birthdate =new SimpleDateFormat("dd-MM-yyyy").parse(bday); 
        String formattedToday = formatter.format(today);
        String[] todayArr = formattedToday.split("-");
        String[] bdayArr = bday.split("-");
        
        
        if(todayArr!=null && bdayArr!=null &&(todayArr[0]+todayArr[1]).equals(bdayArr[0]+bdayArr[1])) {
            int todayYear = Integer.parseInt(todayArr[2]);
            int bdayYear = Integer.parseInt(bdayArr[2]);
            int yearDiff = todayYear - bdayYear;
            System.out.println("Today is your "+yearDiff+". birthday!");
        }else {
            //how many days left to my bday
        }
    }
    
    public static void main(String[] args) throws Exception {
        bdayCounter("15-03-1995");
    }
}

Answer 1

给定日期（用于生日）和新日期()（用于现在），您可以使用calendar.get(DAY_OF_YEAR)。需要考虑到年份（即生日在今天之前），但这种方式考虑到闰年等。

Answer 2

您可以使用BithDay的日期设置一个新的calendar实例；实例另一个日历，计算差异，如下所示：

    Calendar calBirth = Calendar.getInstance();
    calBirth.set(your_birth);

    Calenar now = Calendar.getInstance();

    long timeRemainingInMillis = calBirth.getTimeMillis() - now.getTimeMillis()

    //Now you should convert millis in what you want i.e. day, hour, min ecc...