获取指定指定时间是今年的第几个星期(日期可调)

//此为获取时间戳指定时间是一年的第几周   Calender
public class DateUtils {


  public static Integer getWeekOfYear(Date date) {
      Calendar calendar = Calendar.getInstance();
      calendar.setFirstDayOfWeek(Calendar.MONDAY);
      calendar.setTime(date);
      int week = calendar.get(Calendar.WEEK_OF_YEAR);
      int mouth = calendar.get(Calendar.MONTH);
      // JDK think 2015-12-31 as 2016 1th week
      //如果月份是12月，且求出来的周数是第一周，说明该日期实质上是这一年的第53周，也是下一年的第一周
      if (mouth >= 11 && week <= 1) {
          week += 52;
      }
      return week;
  }

    public static Integer getYearOfDate(Date date) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        return calendar.get(Calendar.YEAR);
    }

    public static Integer weeksBetween(Date fromDate, Date toDate) {
        if (fromDate.before(toDate)) {
            Date temp = fromDate;
            fromDate = toDate;
            toDate = temp;
        }
        Integer weekNum = (getWeekOfYear(fromDate) - getWeekOfYear(toDate))
                + (getYearOfDate(fromDate) - getYearOfDate(toDate)) * 52;
        return ++weekNum;
    }

    public static void main(String[] args) {
         //此为获取   2021年1月10是2021年的第几周
        String formDateString = "2021-01-1 ";
        String toDateString = "2021-01-10 ";
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd ");
        try {
            Date formDate = sdf.parse(formDateString);
            Date toDate = sdf.parse(toDateString);
            System.out.println(weeksBetween(formDate, toDate));
        } catch (ParseException e) {
            e.printStackTrace();
        }

    }

}