CMRDB靜宜大學行雲者研發基地

Java 日期時間函數

DateTime Method

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日期時間類別庫◎java.util.*

java.util.Calendar java.util.GregorianCalendar java.util.TimeZone java.util.SimpleTimeZone java.util.Date

◎java.text.* java.text.DateFormat java.text.SimpleDateFormat java.text.DateFormatSymbols

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java.util.Date

◎宣告物件Date today = new Date();

◎方法抓取時 getHours()抓取分 getMinutes()抓取秒 getSeconds()

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範例import java.util.Date;

public class TimeExample1{

public static void main(String args[])

{

Date nowTime = new Date();

System.out.println(nowTime.getHours()+":“

+nowTime.getMinutes()+":“

+nowTime.getSeconds());

}

}

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java.util.Calendar

◎Calendar 日曆類別◎ 參考網址 http://nothing.tw/JDK_API_1_6/java/util/Calendar.html

◎宣告物件取得現在的時間Calendar today = Calendar.getInstance();

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範例import java.util.Calendar;

public class CalendarExample1{

public static void main(String args[])

{

Calendar today = Calendar.getInstance();

System.out.println(" 現在時區 ERA:"+today.get(Calendar.ERA));

System.out.println(" 現在年份 :"+today.get(Calendar.YEAR));

System.out.println(" 今天日期 :"+today.get(Calendar.DATE));

System.out.println(" 今天是這個月的幾號 :"+today.get(Calendar.DAY_OF_MONTH));

System.out.println(" 今天是這星期的第幾天 :"+today.get(Calendar.DAY_OF_WEEK));

System.out.println(" 現在幾點 :"+today.get(Calendar.HOUR));

}

}

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java.text.DateFormat◎ DateFormat 是日期 / 時間格式化子類別的抽象類別。 ( 設

定日期時間格式用。 )◎ 參考網址 http://nothing.tw/JDK_API_1_6/java/text/DateFormat.html

◎ 方法 getInstance() getDateInstance() getTimeInstance() getDateTimeInstance()

◎ DateFormat. 格式化樣式 FULL LONG MEDIUM SHORT

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範例import java.text.DateFormat;

import java.util.Date;

public class DateFormatExample1 {

public static void main(String[] args) {

Date now = new Date();

System.out.println(" 1. " + now.toString());

System.out.println(" 2. " + DateFormat.getInstance().format(now));

System.out.println(" 3. " + DateFormat.getTimeInstance().format(now));

System.out.println(" 4. " + DateFormat.getDateTimeInstance().format(now));

System.out.println(" 5. " + DateFormat.getTimeInstance(DateFormat.SHORT).format(now));

System.out.println(" 6. " + DateFormat.getTimeInstance(DateFormat.MEDIUM).format(now));

System.out.println(" 7. " + DateFormat.getTimeInstance(DateFormat.LONG).format(now));

// 續下頁

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// 承上頁

System.out.println(" 8. " + DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT).format(now));

System.out.println(" 9. " + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.SHORT).format(now));

System.out.println("10. " + DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG).format(now));

System.out.println("11. " + DateFormat.getDateTimeInstance(DateFormat.FULL, DateFormat.FULL).format(now));

}

}

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SimpleDateFormatimport java.text.SimpleDateFormat;

import java.util.Date;

public class SimpleExample1{

public static void main(String args[])

{

Date today = new Date();

SimpleDateFormat f1=new SimpleDateFormat("yyyy/M/d a h:m");

SimpleDateFormat f2=new SimpleDateFormat("yyyy/MMM/d H:m:s");

System.out.println(f1.format(today));

System.out.println(f2.format(today));

}

}

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java.text.SimpleDateFormat

Symbol

Meaning Type Example

G Era Text “GG” -> “AD”y Year Number “yy” -> “03″

“yyyy” -> “2003″

M Month Text or Number “M” -> “7″“M” -> “12″“MM” -> “07″“MMM” -> “Jul”“MMMM” -> “December”

d Day in month Number “d” -> “3″“dd” -> “03″

E Day in week Text “EEE” -> “Tue”“EEEE” -> “Tuesday”

D Day in year (1-365 or 1-364)

Number “D” -> “65″“DDD” -> “065″

F Day of week in month (1-5)

Number “F” -> “1″

w Week in year (1-53) Number “w” -> “7″W Week in month (1-5) Number “W” -> “3″z Time zone Text “z” -> “EST”

“zzz” -> “EST”“zzzz” -> “Eastern Standard Time”

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java.text.SimpleDateFormat

Symbol Meaning Type Exampleh Hour (1-12, AM/PM) Number “h” -> “3″

“hh” -> “03″

H Hour (0-23) Number “H” -> “15″“HH” -> “15″

k Hour (1-24) Number “k” -> “3″“kk” -> “03″

K Hour (0-11 AM/PM) Number “K” -> “15″“KK” -> “15″

m Minute Number “m” -> “7″“m” -> “15″“mm” -> “15″

s Second Number “s” -> “15″“ss” -> “15″

S Millisecond (0-999) Number “SSS” -> “007″

a AM/PM Text “a” -> “AM”“aa” -> “AM”

‘ Excape for text Delimiter “‘hour’ h” -> “hour 9″

” Single quote Literal “ss”SSS” -> “45′876″