连表查询计算分页pageNo与pageSize

按特定值分组得到count

1、转数组后计算
得到start、end即limit #{start},#

	UserBlockDeptGroupTo[] groupTos = userBlockDeptGroupTos.toArray(new UserBlockDeptGroupTo[0]);
        Integer pageNo = employeePageTo.getPageNo();
        Integer pageSize = employeePageTo.getPageSize();
        int pages = (int) Math.ceil(1.0 * groupTos.length / pageSize);
        int arrStart = (pageNo - 1) * pageSize;
        int start = 0;
        //注意索引越界问题
        for (int i = 0; i < arrStart; i++) {
            if (i<groupTos.length) start += groupTos[i].getCount();
        }
        if (pageNo == 1) start = 0;
        int arrEnd = arrStart + pageSize;
        int end = 0;
        for (int i = arrStart; i < arrEnd; i++) {
            if (i<groupTos.length) end += groupTos[i].getCount();
        }