java 日期格式相互转化

1 java日期format 相关的说明

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 (context sensitive)	Month	July; Jul; 07
L	Month in year (standalone form)	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

 

2 转化示例

1. import java.text.DateFormat;
   import java.text.SimpleDateFormat;
   import java.util.Date;
   public class DateToStringDemo{
      public static void main(String args[])
      {
          Date todaysDate = new Date();
          DateFormat df = new SimpleDateFormat("dd/MM/yyyy");
          DateFormat df2 = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
          DateFormat df3 = new SimpleDateFormat("dd-MMM-yyyy");
          DateFormat df4 = new SimpleDateFormat("MM dd, yyyy");
          DateFormat df5 = new SimpleDateFormat("E, MMM dd yyyy");
          DateFormat df6 = new SimpleDateFormat("E, MMM dd yyyy HH:mm:ss");
          try
          {
              //format() method Formats a Date into a date/time string. 
              String testDateString = df.format(todaysDate);
              System.out.println("String in dd/MM/yyyy format is: " + testDateString);
              String str2 = df2.format(todaysDate);
              System.out.println("String in dd-MM-yyyy HH:mm:ss format is: " + str2);
              String str3 = df3.format(todaysDate);
              System.out.println("String in dd-MMM-yyyy format is: " + str3);
              String str4 = df4.format(todaysDate);
              System.out.println("String in MM dd, yyyy format is: " + str4);
              String str5 = df5.format(todaysDate);
              System.out.println("String in E, MMM dd yyyy format is: " + str5);
              String str6 = df6.format(todaysDate);
              System.out.println("String in E, E, MMM dd yyyy HH:mm:ss format is: " + str6);
          }
          catch (Exception ex ){
             System.out.println(ex);
          }
       }
   }
   //输出
   String in dd/MM/yyyy format is: 02/01/2014
   String in dd-MM-yyyy HH:mm:ss format is: 02-01-2014 22:38:35
   String in dd-MMM-yyyy format is: 02-Jan-2014
   String in MM dd, yyyy format is: 01 02, 2014
   String in E, MMM dd yyyy format is: Thu, Jan 02 2014
   String in E, E, MMM dd yyyy HH:mm:ss format is: Thu, Jan 02 2014 22:38:35

    

1. import java.text.DateFormat;
   import java.text.SimpleDateFormat;
   import java.util.Date;
   public class StringToDateDemo{
      public static void main(String args[])
      {
          String testDateString = "02/04/2014";
          String testDateString2 = "02-04-2014 23:37:50";
          String testDateString3 = "02-Apr-2014";
          String testDateString4 = "04 02, 2014";
          String testDateString5 = "Thu, Apr 02 2014";
          String testDateString6 = "Thu, Apr 02 2014 23:37:50";
          DateFormat df = new SimpleDateFormat("dd/MM/yyyy");
          DateFormat df2 = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
          DateFormat df3 = new SimpleDateFormat("dd-MMM-yyyy");
          DateFormat df4 = new SimpleDateFormat("MM dd, yyyy");
          DateFormat df5 = new SimpleDateFormat("E, MMM dd yyyy");
          DateFormat df6 = new SimpleDateFormat("E, MMM dd yyyy HH:mm:ss");
          try
          {
              //format() method Formats a Date into a date/time string. 
              Date d1 = df.parse(testDateString);
              System.out.println("Date: " + d1);
              System.out.println("Date in dd/MM/yyyy format is: "+df.format(d1));
              Date d2 = df2.parse(testDateString2);
              System.out.println("Date: " + d2);
              System.out.println("Date in dd-MM-yyyy HH:mm:ss format is: "+df2.format(d2));
              Date d3 = df3.parse(testDateString3);
              System.out.println("Date: " + d3);
              System.out.println("Date in dd-MMM-yyyy format is: "+df3.format(d3));
              Date d4 = df4.parse(testDateString4);
              System.out.println("Date: " + d4);
              System.out.println("Date in MM dd, yyyy format is: "+df4.format(d4));
              Date d5 = df5.parse(testDateString5);
              System.out.println("Date: " + d5);
              System.out.println("Date in E, MMM dd yyyy format is: "+df5.format(d5));
              Date d6 = df6.parse(testDateString6);
              System.out.println("Date: " + d6);
              System.out.println("Date in E, E, MMM dd yyyy HH:mm:ss format is: "+df6.format(d6));
          }
          catch (Exception ex ){
             System.out.println(ex);
          }
      }
   }
   //output
   Date: Wed Apr 02 00:00:00 IST 2014
   Date in dd/MM/yyyy format is: 02/04/2014
   Date: Wed Apr 02 23:37:50 IST 2014
   Date in dd-MM-yyyy HH:mm:ss format is: 02-04-2014 23:37:50
   Date: Wed Apr 02 00:00:00 IST 2014
   Date in dd-MMM-yyyy format is: 02-Apr-2014
   Date: Wed Apr 02 00:00:00 IST 2014
   Date in MM dd, yyyy format is: 04 02, 2014
   Date: Wed Apr 02 00:00:00 IST 2014
   Date in E, MMM dd yyyy format is: Wed, Apr 02 2014
   Date: Wed Apr 02 23:37:50 IST 2014
   Date in E, E, MMM dd yyyy HH:mm:ss format is: Wed, Apr 02 2014 23:37:50

    

格式例子：

1. dd-MM-yy 31-01-12
   dd-MM-yyyy 31-01-2012
   MM-dd-yyyy 01-31-2012
   yyyy-MM-dd 2012-01-31
   yyyy-MM-dd HH:mm:ss 2012-01-31 23:59:59
   yyyy-MM-dd HH:mm:ss.SSS 2012-01-31 23:59:59.999
   yyyy-MM-dd HH:mm:ss.SSSZ 2012-01-31 23:59:59.999+0100
   EEEEE MMMMM yyyy HH:mm:ss.SSSZ Saturday November 2012 10:45:42.720+0100
   
   yyyy-MM-dd'T'HH:mm:ssZZZZ 2017-02-19T22:36:06-0800
   
   dd-MM-yyyy EEEE hh:mm:ss a 22-11-2017 Wednesday 12:16:38 PM

    

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