Change date format in a Java string
I've a String
representing a date.
String date_s = "2011-01-18 00:00:00.0";
I'd like to convert it to a Date
and output it in YYYY-MM-DD
format.
2011-01-18
How can I achieve this?
Okay, based on the answers I retrieved below, here's something I've tried:
String date_s = " 2011-01-18 00:00:00.0";
SimpleDateFormat dt = new SimpleDateFormat("yyyyy-mm-dd hh:mm:ss");
Date date = dt.parse(date_s);
SimpleDateFormat dt1 = new SimpleDateFormat("yyyyy-mm-dd");
System.out.println(dt1.format(date));
But it outputs 02011-00-1
instead of the desired 2011-01-18
. What am I doing wrong?
Use LocalDateTime#parse()
(or ZonedDateTime#parse()
if the string happens to contain a time zone part) to parse a String
in a certain pattern into a LocalDateTime
.
String oldstring = "2011-01-18 00:00:00.0";
LocalDateTime datetime = LocalDateTime.parse(oldstring, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.S"));
Use LocalDateTime#format()
(or ZonedDateTime#format()
) to format a LocalDateTime
into a String
in a certain pattern.
String newstring = datetime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd"));
System.out.println(newstring); // 2011-01-18
Or , when you're not on Java 8 yet, use SimpleDateFormat#parse()
to parse a String
in a certain pattern into a Date
.
String oldstring = "2011-01-18 00:00:00.0";
Date date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S").parse(oldstring);
Use SimpleDateFormat#format()
to format a Date
into a String
in a certain pattern.
String newstring = new SimpleDateFormat("yyyy-MM-dd").format(date);
System.out.println(newstring); // 2011-01-18
See also:
Update : as per your failed attempt: the patterns are case sensitive . Read the java.text.SimpleDateFormat
javadoc what the individual parts stands for. So stands for example M
for months and m
for minutes. Also, years exist of four digits yyyy
, not five yyyyy
. Look closer at the code snippets I posted here above.
Formatting are CASE-SENSITIVE so USE MM for month not mm (this is for minute) and yyyy For Reference you can use following cheatsheet.
G Era designator Text AD
y Year Year 1996; 96
Y Week year Year 2009; 09
M Month in year 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
Examples:
"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.SSS'Z'" 2001-07-04T12:08:56.235-0700
"yyyy-MM-dd'T'HH:mm:ss.SSSXXX" 2001-07-04T12:08:56.235-07:00
"YYYY-'W'ww-u" 2001-W27-3
The answer is of course to create a SimpleDateFormat object and use it to parse Strings to Date and to format Dates to Strings. If you've tried SimpleDateFormat and it didn't work, then please show your code and any errors you may receive.
Addendum: "mm" in the format String is not the same as "MM". Use MM for months and mm for minutes. Also, yyyyy is not the same as yyyy. eg,:
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class FormateDate {
public static void main(String[] args) throws ParseException {
String date_s = "2011-01-18 00:00:00.0";
// *** note that it's "yyyy-MM-dd hh:mm:ss" not "yyyy-mm-dd hh:mm:ss"
SimpleDateFormat dt = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
Date date = dt.parse(date_s);
// *** same for the format String below
SimpleDateFormat dt1 = new SimpleDateFormat("yyyy-MM-dd");
System.out.println(dt1.format(date));
}
}
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