Why is this Date string failing the validation?

Question

I have a JSON file with a value of 2020-03-07T04:11:20.000 for a field with given pattern yyyy-MM-dd'T'HH:mm:ss.SSS. I tried to add a Z at the end of it, but it keeps failing the validation. Any idea why?

I tried to do OffsetDateTime.parse(mytext, DateTimeFormatter.ofPattern(mypattern)) and it threw DateTimeParseException with Unable to obtain OffsetDateTime from TemporalAccessor

What is the exception being thrown, if any? Show the code that is producing this. — Jason, Aug 20 '20 at 12:42
I tried to do OffsetDateTime.parse(mytext, DateTimeFormatter.ofPattern(mypattern)) and it threw DateTimeParseException with Unable to obtain OffsetDateTime from TemporalAccessor — user998692, Aug 20 '20 at 12:45
The field in the json has type OffsetDateTime and is annotated with that pattern. — user998692, Aug 20 '20 at 12:46
There is no offset in the `String`, you will have to add one when parsing... — deHaar, Aug 20 '20 at 12:47
What do you mean by offset? Could you please give me an example of amended string? — user998692, Aug 20 '20 at 12:49
I mean something inside the `String` that tells how many hours the value differs from UTC. For example: `2020-03-07T04:11:20.000+01:00` — deHaar, Aug 20 '20 at 12:51
The JSON annotation is @JsonFormat(shape=Shape.String, pattern = my pattern, timezone="UTC"). — user998692, Aug 20 '20 at 12:55
@user998692 Thank you for providing a wealth of good information in response comments. It’s even better to [edit](https://stackoverflow.com/posts/63505330/edit) the question and add all the information there so we have everything in one place. — Ole V.V., Aug 21 '20 at 18:13

score 4 · Accepted Answer · answered Aug 20 '20 at 12:51

Since neither the pattern nor the input has a timezone offset, you can't parse it directly to OffsetDateTime. What you can do is parse the date as LocalDateTime and add the offset to the result.

For example, using ZoneOffset.UTC:

LocalDateTime ldt = LocalDateTime.parse(mytext, DateTimeFormatter.ofPattern(mypattern));
OffsetDateTime odt = ldt.atOffset(ZoneOffset.UTC)

score 2 · Answer 2 · answered Aug 20 '20 at 19:37

First of all, you are using the wrong class, OffsetDateTime for your case. Since you have mentioned timezone="UTC", you should use ZonedDateTime. Note that after using the following annotation, the date-time produced will be like 2020-03-07T04:11:20.000 UTC.

@JsonFormat(shape=JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss.SSS z", timezone="UTC")

which you can parse into ZonedDateTime using the pattern, yyyy-MM-dd'T'HH:mm:ss.SSS z.

Demo:

import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;

public class Main {
    public static void main(String[] args) {
        String myPattern = "yyyy-MM-dd'T'HH:mm:ss.SSS z";
        String myText = "2020-03-07T04:11:20.000 UTC";
        System.out.println(ZonedDateTime.parse(myText, DateTimeFormatter.ofPattern(myPattern)));
    }
}

Output:

2020-03-07T04:11:20Z[UTC]

If you want to keep the date-time format as 2020-03-07T04:11:20.000 then you should remove timezone="UTC" from the annotation and parse the obtained date-time string into a LocalDateTime instead of ZonedDateTime. Needless to say that the pattern should be yyyy-MM-dd'T'HH:mm:ss.SSS in that case.

Why is this Date string failing the validation?

2 Answers2