java-using SimpleDateFormat to format time output

Before a blog is to use NSDateFormatter to format the output of time, but the use of a bit cumbersome, today introduced under the recently used SimpleDateFormat.

1  Public class extends DateFormat

Date and Time mode

Date and time formats are specified by a date and time pattern string. In a date and time pattern string, the unquoted letters ‘A‘ to ‘Z‘ and ‘a‘ to ‘z‘ are interpreted as pattern letters, which are used to represent date or time string elements. Text can be caused by using single quotation marks ( ‘ ) to avoid interpretation. "‘‘"represents a single quotation mark. All other characters are not interpreted; Simply copy them to the output string when they are formatted, or match the input string when parsing.

The following pattern letters are defined (all other characters ‘A‘ to ‘Z‘ and ‘a‘ to ‘z‘ are preserved):

Letters	date or time element	represents	Example
G	Era Marker	Text	AD
y	Years	Year	1996;96
M	Month of the Year	Month	July; Jul;07
w	Number of weeks in the year	Number	27
W	Number of weeks in the month	Number	2
D	Number of days in the year	Number	189
d	Number of days in month	Number	10
F	Week of the Month	Number	2
E	Days of the Week	Text	Tuesday;Tue
a	AM/PM Mark	Text	PM
H	Number of hours in the day (0-23)	Number	0
k	Number of hours in the day (1-24)	Number	24
K	Number of hours in am/pm (0-11)	Number	0
h	Number of hours in am/pm (1-12)	Number	12
m	Number of minutes in hours	Number	30
s	Number of seconds in minutes	Number	55
S	Number of milliseconds	Number	978
z	Time	General Time Zone	Pacific Standard Time; PST;GMT-08:00
Z	Time	RFC 822 Time Zone	-0800

Example The following example shows how to interpret the date and time patterns in the U.S. locale. Given the date and time of the United States Pacific Time zone for local time 2001-07-04 12:08:56.

Date and Time mode	Results
"yyyy.MM.dd G ‘at‘ HH:mm:ss z"	2001.07.04 AD at 12:08:56 PDT
"EEE, MMM d, ‘‘yy"	Wed, Jul 4, ‘01
"h:mm a"	12:08 PM
"hh ‘o‘‘clock‘ a, zzzz"	12 o‘clock PM, Pacific Daylight Time
"K:mm a, z"	0:08 PM, PDT
"yyyyy.MMMMM.dd GGG hh:mm aaa"	02001.July.04 AD 12:08 PM
"EEE, d MMM yyyy HH:mm:ss Z"	Wed, 4 Jul 2001 12:08:56 -0700
"yyMMddHHmmssZ"	010704120856-0700
"yyyy-MM-dd‘T‘HH:mm:ss.SSSZ"	2001-07-04T12:08:56.235-0700

Common construction Methods:

SimpleDateFormat Sformat = new SimpleDateFormat (String pattern);

Or

SimpleDateFormat Sformat = new SimpleDateFormat ();

Sformat.applypattern (String pattern);

Or

DateFormat DateFormat = dateformat.getdateinstance (DateFormat. full, Locale.getdefault ());

Specific desirable dateformat.short,default,long,full, etc.

Sample code

1  Public voidTestcalendar () {2Calendar C1 =calendar.getinstance (); 3C1.settime (NewDate ()); 4           5         //when the time set in the calendar exceeds the maximum value for each item, the time is set with the value minus the maximum, such as the month setting of 13, and finally the 13-11=026Calendar C2 =calendar.getinstance (); 7C2.set (1920, 13, 24, 22, 32, 22); 8         //using the pattern9SimpleDateFormat format =NewSimpleDateFormat ("Yyyy-mm-dd h:m:s"); TenSimpleDateFormat FORMAT2 =NewSimpleDateFormat ("Yy-mm-dd h:m:s");  OneSimpleDateFormat FORMAT3 =NewSimpleDateFormat ("Y-m-d h:m:s");  A         //Use contract Format -    -DateFormat DateFormat =dateformat.getdateinstance (Dateformat.full, Locale.getdefault ());  the          //ways to get the individual attribute fields in the calendar -Log.info ("The Year now time is" +C1.get (C1.  year));  -Log.info ("The Month now time is" +C1.get (C1.  MONTH));  -Log.info ("The Day_of_month now time is" +C1.get (C1.  Day_of_month));  +Log.info ("The Day_of_week now time is" +C1.get (C1.  Day_of_week));  -Log.info ("Today is the first few weeks of the month:" +C1.get (C1.  Day_of_week_in_month));  +Log.info ("The Day_of_year now time is" +C1.get (C1.  Day_of_year));  A         //different modes correspond to a slightly different format, there is time to test a little more mode atLog.info ("Yyyy-mm-dd h:m:s-->" +Format.format (C1.gettime ()));  -Log.info ("Yy-mm-dd h:m:s-->" +Format2.format (C1.gettime ()));  -Log.info ("y-m-d h:m:s-->" +Format3.format (C1.gettime ()));  -Log.info ("dateformat.full-->" +Dateformat.fomat (C1.gettime ()));  - Log.info (Format.format (C2.gettime ()));  -}

java-using SimpleDateFormat to format time output