code: public static int getMonthSpan(Date begin, Date end) {
          Calendar beginCal = new GregorianCalendar();
          beginCal.setTime(begin);
          Calendar endCal = new GregorianCalendar();
          endCal.setTime(end);
          int m = (endCal.get(Calendar.MONTH)) - (beginCal.get(Calendar.MONTH));
          int y = (endCal.get(Calendar.YEAR)) - (beginCal.get(Calendar.YEAR));
          return y * 12 + m;
      }
docs: #func 获取月份差<br>
  
  @author dongguoshuang