LocalDateTime 주요 메소드 정리

포스트 작성 날짜에서 일자만 뽑아내는 로직을 구현 중에,

@CreatedDate 로 생성한 생성일을 가져와서 어떻게 일자만 뽑아낼지 고민했다.

처음에는 String처럼 슬라이싱하여 일자만 뽑아낼 수 있지 않을까? 했었는데

구글링을 해보니, LocalDateTime 메소드에 이미 일자를 뽑아내는 메소드가 존재했다.

아래의 코드로 한번에 LocalDateTIme의 메소드들을 살펴보자.

 

LocalDateTime 메소드 예제

LocalDate today = Year.of(2017).atMonth(12).atDay(17);
System.out.println("Today : " + today);
System.out.println("Year : " + today.getYear());
System.out.println("Month : " + today.getMonth());
System.out.println("DayOfMonth : " + today.getDayOfMonth());
System.out.println("DayOfWeek : " + today.getDayOfWeek());
System.out.println("IsLeapYear : " + today.isLeapYear());

System.out.println("1 year after today: " + today.plusYears(1));
System.out.println("1 month after today: " + today.plusMonths(1));
System.out.println("1 day after today: " + today.plusDays(1));

LocalDate yesterday = today.minusDays(1);
System.out.println("Today is after yesterday? " + today.isAfter(yesterday));
System.out.println("Today is before yesterday? " + today.isBefore(yesterday));

LocalDateTime now = today.atTime(22, 46, 17, 348);
System.out.println("Now : " + now);
System.out.println("Hour: " + now.getHour());
System.out.println("Minute: " + now.getMinute());
System.out.println("Second: " + now.getSecond());
System.out.println("Nano: " + now.getNano());

Today : 2017-12-17
Year : 2017
Month : DECEMBER
DayOfMonth : 17
DayOfWeek : SUNDAY
IsLeapYear : false
1 year after today: 2018-12-17
1 month after today: 2018-01-17
1 day after today: 2017-12-18
Today is after yesterday? true
Today is before yesterday? false
Now : 2017-12-17T22:46:17.000000348
Hour: 22
Minute: 46
Second: 17
Nano: 348

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예제 출처

[Java8 Time API] LocalDate, LocalTime, LocalDateTime 사용법

[Java8 Time API] LocalDate, LocalTime, LocalDateTime 사용법