时间操作,根据起始--结束时间按周划分

需求是这样的,从数据库查到课程的开始和结束时间然后根据周来划分,先初步划分出时间

主要代码

  public List<HmScheduleTest> selectCourseSchedule(){
        List<HmScheduleTest>  list=new ArrayList<HmScheduleTest>();
        //根据教练或天使老师查询出课程id
        //未写...
        //根据课程ID查询课程信息
        String id="0ae00bcc-eb0c-4495-88ae-be30e40eff6e";
        HmCourseCase hmCourseCase = hmCourseCaseMapper.selectByPrimaryKey(id);
        SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss" );
        //判断开始日期是周几
          //开始时间
         Calendar c= Calendar.getInstance();
         c.setTime(hmCourseCase.getBeginTime());//开始时间
         //结束时间
        Calendar d= Calendar.getInstance();
        d.setTime(hmCourseCase.getEndTime());//结束时间
        //计算开始时间为周几
        int dayForWeek=0 ;//开始时间为周几
          if (c.get(Calendar.DAY_OF_WEEK)==1 ){
             dayForWeek=7 ;
          }else {
            dayForWeek=c.get(Calendar.DAY_OF_WEEK)-1;
          }
          //计算结束时间为周几
        int dayEndWeek=0 ;//结束时间为周几
        if (d.get(Calendar.DAY_OF_WEEK)==1 ){
            dayEndWeek=7 ;
        }else {
            dayEndWeek=d.get(Calendar.DAY_OF_WEEK)-1;
        }
          Date start=c.getTime();
          Date end=d.getTime();
          String aa=format.format(start);

          //计算两个时间之间相差多少天
        long startDay = c.getTime().getTime();//把时间转换为毫秒
        long endDay = d.getTime().getTime();//把时间转换为毫秒
        long days=(endDay-startDay)/86400000;//相差天数 86400000:一天时间的毫秒数
        long days2=days+dayForWeek+(7-dayEndWeek);
        long weeks=days2/7;//计算出一共分几周
        long oneWeeksEnd=0;
        for (int i=1;i<=weeks;i++){
            if(i==1){//判断当前为第一周时
                //第一周
               // startDay 开始时间 然后再转化为yyyy-mm-dd HH:mm:ss
                String beginweeks=format.format(start);//第一周开始时间
                //计算本周结束时间
                oneWeeksEnd=startDay+(7-dayForWeek)*86400000;//得到毫秒数
                Calendar calendar = Calendar.getInstance();
                calendar.setTimeInMillis(oneWeeksEnd);//Date日期
                //结束时间
                String endweeks=format.format(oneWeeksEnd);//转化为yyyy-mm-dd HH:mm:ss
                //根据本周开始时间和结束时间查询电话数和作业数
                HmScheduleTest hmScheduleTest=new HmScheduleTest(i,beginweeks,endweeks);
                list.add(hmScheduleTest);

            }else if (i==weeks){//判断当前为最后一周时
                long beginweeksMill=oneWeeksEnd+86400000+(i-2)*7*86400000;//当前周开始时间
                Calendar calendarbegin = Calendar.getInstance();
                calendarbegin.setTimeInMillis(beginweeksMill);
                Date datebegin= calendarbegin.getTime();
                //当前周开始时间转化为yyyy-mm-dd HH:mm:ss
                String beginweeks=format.format(datebegin);
                long endweeksMill=beginweeksMill+(dayEndWeek-1)*86400000;
                Calendar calendarend = Calendar.getInstance();
                calendarend.setTimeInMillis(endweeksMill);
                //当前周结束时间转化为yyyy-mm-dd HH:mm:ss
                Date dateend= calendarend.getTime();
                String endweeks=format.format(dateend);
                HmScheduleTest hmScheduleTest=new HmScheduleTest(i,beginweeks,endweeks);
                list.add(hmScheduleTest);
            }else {
                //long beginweeksMill=startDay+((7-dayForWeek)+(i-1)*7)*86400000;//当前周开始时间
                long beginweeksMill=oneWeeksEnd+86400000+(i-2)*7*86400000;
                Calendar calendarbegin = Calendar.getInstance();
                calendarbegin.setTimeInMillis(beginweeksMill);
                Date datebegin= calendarbegin.getTime();
                //当前周开始时间转化为yyyy-mm-dd HH:mm:ss
                String beginweeks=format.format(datebegin);
                long endweeksMill=beginweeksMill+6*86400000;
                Calendar calendarend = Calendar.getInstance();
                calendarend.setTimeInMillis(endweeksMill);
                //当前周结束时间转化为yyyy-mm-dd HH:mm:ss
                Date dateend= calendarend.getTime();
                String endweeks=format.format(dateend);
                HmScheduleTest hmScheduleTest=new HmScheduleTest(i,beginweeks,endweeks);
                list.add(hmScheduleTest);
            }
        }
        return list;

时间是

最后返回的结果