java 中获取2个时间段中所包含的周数(股票的周数->从周六到周五)

Calendar 类中是以周日为开始的第一天的,所以Calendar.DAY_OF_WEEK为1的时候是周日.

在股票中有日K 周K和月K的数据. 

在此之中的周K是指交易日中一周的数据,周六到周五为一个周期.

 /**

      * 返回2个日期间有多少股票周

      * @param startDate 2012-02-01 开始日期

      * @param endDate  2014-02-01   结束日期

      * @return

      */

     public static  int getStockWeeks(String  startDate,String endDate){

         int a = 0;

         try {

             SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

             Calendar before = Calendar.getInstance();

             Calendar after = Calendar.getInstance();

             Calendar temp = Calendar.getInstance();

             before.setTime(sdf.parse(startDate));

             after.setTime(sdf.parse(endDate));

             long time1 = before.getTime().getTime();

             long time2 = after.getTime().getTime();

             if(time1>time2){//开始和结束时间对换了(有可能前后时间给错了)

                 temp=before;

                 before=after;

                 after=temp;

             }

             int week = before.get(Calendar.DAY_OF_WEEK);

             before.add(Calendar.DATE, -week);//并非周一为第一天  周六为第一天

             week = after.get(Calendar.DAY_OF_WEEK);

             if(week>0&&week<7)after.add(Calendar.DATE, 6 - week);

             if(week==7)after.add(Calendar.DATE, 6);

             a= (int) ((after.getTimeInMillis() - before

                     .getTimeInMillis()) / CONST_WEEK);

             a = a - 1;

             if (a == 0) {

                 a = 1;

             }

         } catch (Exception e) {

             e.printStackTrace();

         }

         return a;

     }