DateTimeFormatterBuilder with default zone id?

Question

I have a requirement where if ISO date time does not specify zone offset, I should assume Europe/Bratislava's current offset.

Basically "2020-03-26T22:47:32.497" -> "2020-03-26T22:47:32.497+01:00"

Tldr; do parse time zone id if there is one, but default to a specific one if none is present

What I have now

private val isoDateTimeParser = DateTimeFormatterBuilder()
    .append(DateTimeFormatter.ISO_OFFSET_DATE_TIME)
    .parseDefaulting(ChronoField...?)
    .toFormatter()

Obviously it doesnt work. Is it even possible? Should I just have 2 formatters (one with tz, one without) and try one after another?

Michael · Answer 1 · 2020-03-26T23:48:15.650

1

Add an "override zone" to the formatter with withZone

private val isoDateTimeParser = DateTimeFormatterBuilder()
    .append(DateTimeFormatter.ISO_DATE_TIME)
    .toFormatter()
    .withZone(/*whatever*/)

From the docs

If a zone has been parsed directly from the text, perhaps because DateTimeFormatterBuilder.appendZoneId() was used, then this override zone has no effect

By the way, there is very rarely any reason for a formatter to be an instance variable. It should be static. Given that it's immutable, and therefore a constant, it should be upper case as well.

private static final ISO_DATE_TIME_PARSER = ...

edited Mar 26 '20 at 23:48

answered Mar 26 '20 at 22:26

Michael

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doesnt work. `org.threeten.bp.format.DateTimeParseException: Text '2020-03-26T22:47:32.497' could not be parsed at index 23` – urSus Mar 26 '20 at 22:45
@urSus ISO_OFFSET_DATE_TIME does not have an optional offset, it is mandatory. – Michael Mar 26 '20 at 23:48
well thats my whole question, how to attach a default to optional timezone – urSus Mar 27 '20 at 00:02
@urSus See the edit friend – Michael Mar 27 '20 at 00:02

DateTimeFormatterBuilder with default zone id?

1 Answers1