String startDt = param.get("startDt2").toString();
String endDt = param.get("endDt2").toString();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
//날짜 차이 계산을 위해 문자열->Date
Date startDay = sdf.parse(startDt);
Date endDay = sdf.parse(endDt);
long diffDay = (endDay.getTime() - startDay.getTime()) / (24*60*60*1000);
int n = ((int) diffDay)+1;; //날짜 차이