convert iso to utc format in java

user_17424027 0
Viewed 113

I'm getting below exception while converting date string from ISO to UTC format in java, what I'm doing wrong here? Please find my code below:

Test.java

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

public class Test {
    public static void main(String[] args) {
        String date="2020-11-02T07:00:00.114";
        String result = LocalDateTime.parse(date, DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss")).atOffset(ZoneOffset.UTC).toString();
        System.out.println("result: "+result);
    }
}

Exception:

Exception in thread "main" java.time.format.DateTimeParseException: Text '2020-11-02T07:00:00.114' could not be parsed, unparsed text found at index 19
    at java.base/java.time.format.DateTimeFormatter.parseResolved0(DateTimeFormatter.java:2049)
    at java.base/java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1948)
    at java.base/java.time.LocalDateTime.parse(LocalDateTime.java:492)
    at test.service.Test.main(Test.java:11)
iso utc date java
3 Answers

tl;dr

LocalDateTime
.parse( "2020-11-02T07:00:00.114" ) 
.atOffset( ZoneOffset.UTC )
.toString()

2020-11-02T07:00:00.114Z

Details

You said:

converting date string from ISO to UTC format

That does not exactly make sense.

  • There is an ISO 8601 standard defining sensible formats for exchanging date-time values textually. These standard formats are used by default when parsing/generating text.
  • There is no such thing as "UTC format". UTC is the temporal prime meridian, against which all time zones are defined. The rules for a time zone specify an offset-from-UTC in effect as a number of hours-minutes-seconds ahead or behind UTC. But this has nothing to with "formats" of text.

As for parsing your input string as a LocalDateTime object, there is no need to bother with defining a formatting pattern. Your string complies with ISO 8601, so it can be parsed directly.

LocalDateTime ldt = LocalDateTime.parse( "2020-11-02T07:00:00.114" ) ;

Your string, and a LocalDateTime object, represent a date with a time-of-day. But both lack the context of a time zone or offset-from-UTC.

Apparently you know that the publisher of your input string intended that to be a moment as seen from an offset of zero hours-minutes-seconds from UTC. So we can assign a ZoneOffset to get OffsetDateTime object.

OffsetDateTime odt = ldt.atOffset( ZoneOffset.UTC ) ;

To generate text representing that moment in ISO 8601 format, simply call toString.

String output = odt.toString() ;

See this code run live at Ideone.com.

2020-11-02T07:00:00.114Z

Notice the Z on the end, pronounced “Zulu”. That is an abbreviation for an offset of zero, +00:00.

user_6427060

Your pattern ends in ss, in other words: In seconds. Your input then has still more stuff.

DateTimeFormatter doesn't take a wild stab at it - it either matches properly or it does not parse. It looks like those are intended to be milliseconds; toss .SSS at the end of your pattern.

user_7686440

You are giving the format of:

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

However are specifying a string with fractions of a second 2020-11-02T07:00:00.114.

That is parsing whole seconds, but there is still more in the time string.

You need format of:

yyyy-MM-dd'T'HH:mm:ss.SSS

user_62778310
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