[Java] 날짜 다루기 (Date, Calendar, SimpleDateFormat)

Calendar → Date

Calendar cal = Calendar.getInstance();

cal.set(2021, 07, 24);
Date startDate = cal.getTime();

cal.set(2021, 07, 25);
Date endDate = cal.getTime();

DateFormat df = new SimpleDateFormat("yyyy/MM/dd");
Date d = df.parse("2021/08/14");

오늘 날짜 원하는 데이터 형식으로 변환

SimpleDateFormat sdf = new SimpleDateFormat("YYYY-MM-DD HH:mm:ss");
String dateStr = sdf.format(new Date());