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;
    }