1. CMRDB 靜宜大學行雲者研發基地 Java 日期時間函數 DateTime Method

2. 2 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

3. 3 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()

4. 4 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()); }

5. 5 java.util.Calendar ◎ Calendar 日曆類別 ◎ 參考網址 http://nothing.tw/JDK_API_1_6/java/util/Calendar.html 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();

6. 6 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)); }

7. 7 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.htmlhttp://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

8. 8 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

9. 9 // 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)); }

10. 10 SimpleDateFormat import 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)); }

11. 11 java.text.SimpleDateFormat Symbol MeaningTypeExample GEraText“GG” -> “AD” yYearNumber“yy” -> “03″ “yyyy” -> “2003″ MMonthText or Number“M” -> “7″ “M” -> “12″ “MM” -> “07″ “MMM” -> “Jul” “MMMM” -> “December” dDay in monthNumber“d” -> “3″ “dd” -> “03″ EDay in weekText“EEE” -> “Tue” “EEEE” -> “Tuesday” DDay in year (1-365 or 1-364)Number“D” -> “65″ “DDD” -> “065″ FDay of week in month (1-5)Number“F” -> “1″ wWeek in year (1-53)Number“w” -> “7″ WWeek in month (1-5)Number“W” -> “3″ zTime zoneText“z” -> “EST” “zzz” -> “EST” “zzzz” -> “Eastern Standard Time”

12. 12 java.text.SimpleDateFormat Symbol MeaningTypeExample hHour (1-12, AM/PM)Number“h” -> “3″ “hh” -> “03″ HHour (0-23)Number“H” -> “15″ “HH” -> “15″ kHour (1-24)Number“k” -> “3″ “kk” -> “03″ KHour (0-11 AM/PM)Number“K” -> “15″ “KK” -> “15″ mMinuteNumber“m” -> “7″ “m” -> “15″ “mm” -> “15″ sSecondNumber“s” -> “15″ “ss” -> “15″ SMillisecond (0-999)Number“SSS” -> “007″ aAM/PMText“a” -> “AM” “aa” -> “AM” ‘Excape for textDelimiter“‘hour’ h” -> “hour 9″ ”Single quoteLiteral“ss”SSS” -> “45′876″