I am getting the time object in the form of a string from a rest service . I need to extract the time and then do some time operation.The given time string is "2015-06-16T14:58:48Z". I tried the below code , to convert the string to the time , however , getting incorrect values.
String time = "2015-06-16T14:58:48Z";
SimpleDateFormat formatter = new SimpleDateFormat("YYYY-MM-DD'T'hh:mm:ss'Z'", Locale.US);
String dateInString = "2015-06-16T14:58:48Z";
Date date = formatter.parse(dateInString);
System.out.println("Original String : " + time);
System.out.println("After converting to time : " + formatter.format(date));
The output that i am getting is as below: Original String : 2015-06-16T14:58:48Z After converting to time : 2015-12-362T02:58:48Z
The converted date somehow is getting wrong value.Please suggest where is the mistake.Thanks.
change SimpleDateFormat to this..
SimpleDateFormat formatter = new SimpleDateFormat(
"yyyy-MM-dd'T'HH:mm:ssX", Locale.US);
You format string has a couple of mistakes:
Y
means the week year , not the year , which is y
D
means the day of the year . You should have used d
, which means the day of the month .h
means a 12-hour notation time of day. Since you have 14
you should use H
, which handle a 24-hour notation.To sum it all up:
SimpleDateFormat formatter =
new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX", Locale.US);
The root cause of the problem is using wrong symbols
Y
(which specifies week-based-year ) instead of y
(which specifies year-of-era ) D
(which specifies day-of-year ) instead of d
(which specifies day-of-month ). h
(which specifies clock-hour-of-am-pm ) instead of H
(which specifies hour-of-day ). Check the documentation page to learn more about these symbols.
Also, note that the legacy date-time API ( java.util
date-time types and their formatting API, SimpleDateFormat
) is outdated and error-prone. It is recommended to stop using it completely and switch to java.time
, the modern date-time API * .
Solution using the modern API:
The modern date-time API is based on ISO 8601 and does not require you to use a DateTimeFormatter
object explicitly as long as the date-time string conforms to the ISO 8601 standards. Your date-time string conforms to ISO 8601 standards (or the default format used by OffsetDateTime#parse
).
import java.time.LocalTime;
import java.time.OffsetDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Locale;
public class Main {
public static void main(String[] args) {
String strDateTime = "2015-06-16T14:58:48Z";
OffsetDateTime odt = OffsetDateTime.parse(strDateTime);
System.out.println(odt);
// ########################Extract time information########################
LocalTime time = odt.toLocalTime();
// You can also get it as time.getHour()
// Extract other units in a similar way
int hour = odt.getHour();
// Also using time.format(DateTimeFormatter.ofPattern("a", Locale.ENGLISH));
String amPm = odt.format(DateTimeFormatter.ofPattern("h a", Locale.ENGLISH));
System.out.println(time);
System.out.println(hour);
System.out.println(amPm);
}
}
Output:
2015-06-16T14:58:48Z
14:58:48
14
2 PM
Note:
Z
in the output is the timezone designator for zero-timezone offset. It stands for Zulu and specifies the Etc/UTC
timezone (which has the timezone offset of +00:00
hours).OffsetDateTime
to an object of java.util.Date
, you can do so as follows: Date date = Date.from(odt.toInstant());
Learn more about the the modern date-time API * from Trail: Date Time .
* For any reason, if you have to stick to Java 6 or Java 7, you can use ThreeTen-Backport which backports most of the java.time functionality to Java 6 & 7. If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring and How to use ThreeTenABP in Android Project .
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