How to get nanoseconds since epoch for string formatted time "2019-01-25 14:34:34.123456789" in java?

Question

I am able to parse 2019-01-25 14:34:34.123456789 string and get the object of ZonedDateTime. Now, I want to get time in nanoseconds precision level since epoch from this ZonedDateTime object.

Answer 1

Duration might help:

Something like:

Duration.between(
  ZonedDateTime.ofInstant(Instant.EPOCH, ZoneId.of("UTC")),
  yourZonedDatetime
).toNanos()