字符串和日期的轉(zhuǎn)換_百度文庫(kù)

1、java開(kāi)發(fā)時(shí)往往需要做字符串和日期的轉(zhuǎn)換主要用到：java.text.SimpleDateFormatSimpleDateFormat sdf = new SimpleDateFormat( yyyy-MM-dd HH:mm:ss ; 它確立了轉(zhuǎn)換的格式，為什么有的格式大寫(xiě)，有的格式小寫(xiě)，那是怕避免混淆，例如MM是月份，mm是分；HH是24小 時(shí)制，而hh是12小時(shí)制1.字符串轉(zhuǎn)日期 2008-07-10 19:20:00 要把它轉(zhuǎn)成日期，可以用 Date date = sdf.parse( 2008-07-10 19:20:00 ;2.日期轉(zhuǎn)字符串 假如把今天的日期轉(zhuǎn)成字符串可用 Stri

2、ng str = sdf.format(new Date(;這個(gè)字符串內(nèi)容的格式類似2008-07-10 19:20:00。附編寫(xiě)好的一個(gè)簡(jiǎn)單實(shí)例：import java.util.Date; import java.text.ParseException; import java.text.SimpleDateFormat; public class ConvertDemo /* */* * 日期轉(zhuǎn)換成字符串 * param date * return str */ public static String DateToStr(Date date SimpleDateFormat forma

3、t = new SimpleDateFormat(yyyy-MM-dd HH:mm:ss; String str = format.format(date; return str; /* */* * 字符串轉(zhuǎn)換成日期 * param str * return date */ public static Date StrToDate(String str SimpleDateFormat format = new SimpleDateFormat(yyyy-MM-dd HH:mm:ss; Date date = null; try date = format.parse(str; catch (

4、ParseException e e.printStackTrace(; return date; public static void main(String args Date date = new Date(; System.out.println(日期轉(zhuǎn)字符串： + ConvertDemo.DateToStr(date; System.out.println(字符串轉(zhuǎn)日期： + ConvertDemo.StrToDate(ConvertDemo.DateToStr(date; import java.text.ParseException; import java.text.Simpl

5、eDateFormat; import java.util.Date; /* */* * JAVA中字符串轉(zhuǎn)與日期型的互轉(zhuǎn)實(shí)例 */ public class ExValue /* */* * 取當(dāng)前系統(tǒng)日期，并按指定格式或者是默認(rèn)格式返回 * param format * return */ public static String getNow(String format if(null = format | .equals(format format = yyyy-MM-dd HH:mm:ss; SimpleDateFormat sdf = new SimpleDateFormat(fo

6、rmat; String date = sdf.format(new Date(; return date; /* */* * 將字符型轉(zhuǎn)換為指定格式日期型 * param _date 需要轉(zhuǎn)換成日期的字符串 * param format 與需要轉(zhuǎn)換成日期的字符串相匹配的格式 * return */ private static Date stringToDate(String _date,String format if(null = format | .equals(format format = yyyy-MM-dd HH:mm:ss; SimpleDateFormat sdf = ne

7、w SimpleDateFormat(format; Date date=null; try date=sdf.parse(_date; catch (ParseException e / TODO Auto-generated catch block e.printStackTrace(; return date; /* */* * 將日期型轉(zhuǎn)換為指定格式的字符串 * param date 日期 * param format 格式 * return */ public static String dateToString(Date date,String format if(null = f

8、ormat | .equals(format format = yyyy年MM月dd日 hh點(diǎn):mm分:ss秒; SimpleDateFormat sdf = new SimpleDateFormat(format; return sdf.format(date; public static void main(String args throws Exception /當(dāng)字符串轉(zhuǎn)日期型的時(shí)候，format的格式，一定要和需要轉(zhuǎn)成日期的字符串相匹配 /String dateString=2009-01-01,format=yyyy-MM-dd; String dateString=2009-0

9、1-01 01:01:02,format=yyyy-MM-dd hh:mm:ss; String result=stringToDate(dateString, format.toString(; System.out.println(字符轉(zhuǎn)日期:+result.toString(; System.out.println(日期轉(zhuǎn)字符串:+dateToString(stringToDate(dateString, format,yyyy年MM月dd日 hh點(diǎn):mm分:ss秒; System.currentTimeMillis(;/以毫秒為單位返回當(dāng)前時(shí)間java.util.CalendarCal

10、endar g=Calendar.getInstance(; g.add(Calendar.YEAR,1; SimpleDateFormat s=new SimpleDateFormat(yyyy-MM-dd HH-mm-ss,Locale.US; String d=s.format(g.getTime(; System.out.println(d;Calendar calendar = new GregorianCalendar(; calendar.setTime(date; calendar.add(calendar.DATE,1;/把日期往后增加一天.整數(shù)往后推,負(fù)數(shù)往前移動(dòng) date

11、=calendar.getTime(; Calendar c = Calendar.getInstance(; /得到當(dāng)前日期和時(shí)間c.set(Calendar.HOUR, 0; /把當(dāng)前時(shí)間小時(shí)變成c.set(Calendar.MINUTE, 0; /把當(dāng)前時(shí)間分鐘變成c.set(Calendar.SECOND, 0; /把當(dāng)前時(shí)間秒數(shù)變成c.set(Calendar.MILLISECOND, 0; /把當(dāng)前時(shí)間毫秒變成Date date1 = c.getTime(; /創(chuàng)建當(dāng)天的0時(shí)0分0秒一個(gè)date對(duì)象c.setFirstDayOfWeek(Calendar.SUNDAY; /設(shè)定星期

12、的第一天是星期天c.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY; /把日期變成本周的星期天Date date2 = c.getTime(; /得到這個(gè)星期的星期天0時(shí)0分0秒c.set(Calendar.DAY_OF_WEEK, Calendar.SATURDAY; /把日期變成本周的星期六Date date3 = c.getTime(; /得到這個(gè)星期的星期六0時(shí)0分0秒System.out.println(date1;System.out.println(date2;System.out.println(date3;當(dāng)天0點(diǎn)0分0秒 Calendar calendar=Calendar.getInstance(; calendar.set(Calendar.HOUR_OF_DAY,0; calendar.set(Calendar.MINUTE,0; calendar.set(Calendar.SECOND,0; calendar.set(Calendar.MILLISECOND,0; Date today = calendar.getTime(; 這個(gè)星期的星期天0時(shí)0分0秒和星期六0時(shí)0分0秒 接著上面的 c.add(Calendar.DATE,