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형식화 클래스 : SimpleDateFormat

은은하게미친자 2022. 7. 25. 23:41
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SimpleDateFormat ?

날짜데이터를 원하는 형태로 다양하게 출력하기 위해사용.

 

원하는 출력형식의 패턴을 작성하여 SimpleDateFormat인스턴스를 생성한다음, 출력하고자하는 date 인스턴스를 가지고format을 호출하여 사용.예제참고

 

 * SimpleDateFormat 의 패턴에서 사용되는기호.

Letter Date or Time Component Presentation Examples
G Era designator Text AD
y Year Year 1996; 96
Y Week year Year 2009; 09
M Month in year Month July; Jul; 07
w Week in year Number 27
W Week in month Number 2
D Day in year Number 189
d Day in month Number 10
F Day of week in month Number 2
E Day name in week Text Tuesday; Tue
u Day number of week (1 = Monday, ..., 7 = Sunday) Number 1
a Am/pm marker Text PM
H Hour in day (0-23) Number 0
k Hour in day (1-24) Number 24
K Hour in am/pm (0-11) Number 0
h Hour in am/pm (1-12) Number 12
m Minute in hour Number 30
s Second in minute Number 55
S Millisecond Number 978
z Time zone General time zone Pacific Standard Time; PST; GMT-08:00
Z Time zone RFC 822 time zone -0800
X Time zone ISO 8601 time zone -08; -0800; -08:00

예제

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package Capter10;
 
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
 
public class Ex10_4 {
 
    public static void main(String[] args) {
        Date today = new Date();
        Calendar cal = Calendar.getInstance();
        cal.set(2022,6,24); //7월24일로셋팅
        Date yesterday = cal.getTime();
        
        
        
        SimpleDateFormat sf1 =  new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
        SimpleDateFormat sf2 =  new SimpleDateFormat("yyyy년MM월dd일");
        SimpleDateFormat sf3 =  new SimpleDateFormat("yyyy-MM-dd hh:mm:ss a");
        
        System.out.println("today : " + sf1.format(today));
        System.out.println("today : " + sf2.format(today));
        System.out.println("yesterday : " + sf3.format(yesterday));
        System.out.println("yesterday : " + sf2.format(yesterday));
        
        try {
            Date d = sf2.parse("2012년07월25일");
            System.out.println("10년전 : "+ sf3.format(d));
        } catch (ParseException e) {
            e.printStackTrace();
        }
 
    }
 
}
 
 cs

 

실행결과
today : 2022-07-25 11:39:55
today : 2022년07월25일
yesterday : 2022-07-24 11:39:55 오후
yesterday : 2022년07월24일
10년전 : 2012-07-25 12:00:00 오전
 

 

 

 

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