[날짜] LocalDate, Calendar, Date 날짜 가져오는 방법

출처 : docs.oracle.com/javase/tutorial/i18n/format/simpleDateFormat.html

Date Format Pattern Syntax

You can design your own format patterns for dates and times from the list of symbols in the following table:

SymbolMeaningPresentationExample

G	era designator	Text	AD
y	year	Number	2009
M	month in year	Text & Number	July & 07
d	day in month	Number	10
h	hour in am/pm (1-12)	Number	12
H	hour in day (0-23)	Number	0
m	minute in hour	Number	30
s	second in minute	Number	55
S	millisecond	Number	978
E	day in week	Text	Tuesday
D	day in year	Number	189
F	day of week in month	Number	2 (2nd Wed in July)
w	week in year	Number	27
W	week in month	Number	2
a	am/pm marker	Text	PM
k	hour in day (1-24)	Number	24
K	hour in am/pm (0-11)	Number	0
z	time zone	Text	Pacific Standard Time
'	escape for text	Delimiter	(none)
'	single quote	Literal	'

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JDK1.8.x 부터 Date 를 사용하는 방법이 달라졌습니다.

 

    /**
     * 날짜를 원하는 SimpleDateFormat 에 맞춰 리턴한다.
     * 
     * @param strDate
     * @return
     */
    public static String getDateTimeFormat( String dateFormat ) {
        LocalDateTime nowDate = LocalDateTime.now();
        DateTimeFormatter formatter = null;
        String strDate = "";
        
        try {
            formatter = DateTimeFormatter.ofPattern(dateFormat);
        } catch(Exception e) {
            formatter = DateTimeFormatter.ofPattern("yyyyMMddHHmmss");
        }

        strDate = nowDate.format( formatter );
        
        return strDate;
    }

 

이전에 사용하던 방식 (JDK 1.1 기준)

    /**
     * 날짜를 원하는 SimpleDateFormat 에 맞춰 리턴한다.
     * 
     * @param strDate
     * @return
     */
    public static String getDateTimeFormat_( String dateFormat ) {
        Calendar cal = Calendar.getInstance();
        cal.add(Calendar.DATE, 1);
        SimpleDateFormat simpleDate = null;
        String strDate = "";
        
        try {
            simpleDate = new SimpleDateFormat(dateFormat);
        } catch(Exception e) {
            simpleDate = new SimpleDateFormat("yyyyMMddHHmmss");
        }

        strDate = simpleDate.format(cal.getTime());
        
        return strDate;
    }

 

이전에 사용하던 방식 (JDK 1.0 기준)

    /**
     * 날짜를 원하는 SimpleDateFormat 에 맞춰 리턴한다.
     * 
     * @param strDate
     * @return
     */
    public static String getDateTimeFormat_( String dateFormat ) {
        Date today = new Date();
        SimpleDateFormat simpleDate = null;
        String strDate = "";
        
        try {
            simpleDate = new SimpleDateFormat(dateFormat);
        } catch(Exception e) {
            simpleDate = new SimpleDateFormat("yyyyMMddHHmmss");
        }

        strDate = simpleDate.format(cal.getTime());
        
        return strDate;
    }