背景:
提供任意日期,比如:2023-01-01,计算对应月份的天数
方案一:Calendar
Calendar calendar = Calendar.getInstance();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
calendar.setTime(simpleDateFormat.parse(timeValue));
int days = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
方案二:hutool
DateTime dateTime = DateUtil.parse("2023-01-01");
int days = dateTime.getLastDayOfMonth();