SimpleDateFormat ignoring month when parsing

问题

The following code is giving me the parsed date as "Wed Jan 13 00:00:00 EST 2010" instead of "Wed Jun 13 00:00:00 EST 2010". Any ideas much appreciated.

    SimpleDateFormat sf = new SimpleDateFormat("yyyy-mm-dd'T'HH:mm:ss");

    String str = "2010-06-13T00:00:00";

    Date date = sf.parse(str);

    System.out.println(" Date " + date.toString());

回答1:

Try:

"yyyy-MM-dd'T'HH:mm:ss"

MM means month. mm means minutes. See the documentation for SimpleDateFormat for more details of the supported date and time patterns.

回答2:

The problem is that you're using 'mm' as month and 'mm' represents minutes. Below is all date formats available, read more doc here.

Symbol  Meaning                Kind         Example
D       day in year             Number        189
E       day of week             Text          E/EE/EEE:Tue, EEEE:Tuesday, EEEEE:T
F       day of week in month    Number        2 (2nd Wed in July)
G       era designator          Text          AD
H       hour in day (0-23)      Number        0
K       hour in am/pm (0-11)    Number        0
L       stand-alone month       Text          L:1 LL:01 LLL:Jan LLLL:January LLLLL:J
M       month in year           Text          M:1 MM:01 MMM:Jan MMMM:January MMMMM:J
S       fractional seconds      Number        978
W       week in month           Number        2
Z       time zone (RFC 822)     Time Zone     Z/ZZ/ZZZ:-0800 ZZZZ:GMT-08:00 ZZZZZ:-08:00
a       am/pm marker            Text          PM
c       stand-alone day of week Text          c/cc/ccc:Tue, cccc:Tuesday, ccccc:T
d       day in month            Number        10
h       hour in am/pm (1-12)    Number        12
k       hour in day (1-24)      Number        24
m       minute in hour          Number        30
s       second in minute        Number        55
w       week in year            Number        27
G       era designator          Text          AD
y       year                    Number        yy:10 y/yyy/yyyy:2010
z       time zone               Time Zone     z/zz/zzz:PST zzzz:Pacific Standard

回答3:

Modern answer:

    String str = "2010-06-13T00:00:00";
    LocalDateTime dateTime = LocalDateTime.parse(str);
    System.out.println("Date-time " + dateTime);

Output:

Date-time 2010-06-13T00:00

I am using and recommending java.time, the modern Java date and time API. We don’t even need an explicit formatter for parsing. This is because your string is in ISO 8601 format, the international standard that the java.time classes parse as their default. java.time came out in 2014.

While in 2010 when this question was asked, SimpleDateFormat was what we had for parsing dates and times, that class is now considered long outdated, fortunately, because it was also troublesome.

In case your string contained only a date without time of day, use the LocalDate class in quite the same manner (this was asked in a duplicate question).

    String dateStr = "2018-05-23";
    LocalDate date2 = LocalDate.parse(dateStr);
    System.out.println(date2);

2018-05-23

Link: Oracle tutorial: Date Time explaining how to use java.time.

回答4:

Example if Date is 06 07 2016

SimpleDateFormat sdf= new SimpleDateFormat("dd MM yyyy");

you can use comma, full-stop, slash, or hyphen between these format.

 Ex: dd-mm-yyyy, it will display like(06-07-2016)
 dd/mm/yyyy,it will display like(06/07/2016)
 dd.mm.yyyy,it will display like(06.07.2016)
 dd,mm,yyyy ,it will display like(06,07,2016)

 MM   - will display number of the Month.
 MMM  - will display Month Three character only(Ex: Jul)
 MMMM - will display full month(Ex: July)

 yyyy - will display full year(2016) 
 yy   - will display last two digits(16)

 hh - will display hours
 mm -will display minutes
 ss - will display seconds
 a - will display AM or PM

 Ex: if time is 12:09:10 PM means (hh:mm:ss a)

 EEE- will display short week name(Ex: Wed)
 EEEE- will display full week name(Ex: Wednesday)

来源：https://stackoverflow.com/questions/3056703/simpledateformat-ignoring-month-when-parsing

标签

java

simpledateformat