小编Sha*_*ond的帖子

尝试运行此代码，直到一切正常为止，OCT但是NOV就像 firstdate 2019-12-01 & lastdate 2020-12-31

public class Test1 {
    public static void main(String[] args) {
        Calendar calendar = Calendar.getInstance();         
        calendar.add(Calendar.MONTH, 1);
        String date;    
        calendar.set(Calendar.DATE,calendar.getActualMinimum(Calendar.DAY_OF_MONTH));
        Date nextMonthFirstDay = calendar.getTime();
        date=new SimpleDateFormat("YYYY-MM-dd").format(nextMonthFirstDay).toLowerCase();
        System.out.println("firstdate "+ date);

        calendar.set(Calendar.DAY_OF_MONTH,calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
        Date nextMonthLastDay = calendar.getTime();
        date=new SimpleDateFormat("YYYY-MM-dd").format(nextMonthLastDay).toLowerCase();
        System.out.println("lastdate  "+date);

    }
}

我不知道为什么会这样显示。是Java中的错误还是bug？