Java - Convert a given DateTime in String to local timezone

Question

I am reading a timestamp from a database as a string value, say:

2020-04-30T09:59:00.272-05:00

. Now i have to compare this with current timestamp in local timezone(System timezone)

What i have tried so Far:

ZonedDateTime result = ZonedDateTime.parse("2020-04-30T09:59:00.272-05:00"); System.out.println("Given : "+result); System.out.println("Given In Local: "+result.withZoneSameLocal(ZoneId.systemDefault()));

OutPut: Given : 2020-04-30T09:59:00.272-05:00 Given In Local: 2020-04-30T09:59:00.272-05:00[America/Chicago]

My Desired output is "2020-04-30T14:59:00.272"

Answer 1

You could parse the given date string as an OffsetDateTime, then change its offset and convert it to LocalDateTime as follows

    final String dateString = "2020-04-30T09:59:00.272-05:00";
    final ZonedDateTime result = ZonedDateTime.parse(dateString);
    System.out.println("Given         : " + result);
    final LocalDateTime localDateTime = OffsetDateTime.parse(dateString)
        .atZoneSameInstant(ZoneId.of("Europe/Berlin"))
        .toLocalDateTime();
    System.out.println("Given In Local: " + localDateTime);```

prints

Given         : 2020-04-30T09:59:00.272-05:00
Given In Local: 2020-04-30T16:59:00.272

Besides, you could also parse it to ZonedDateTime and then change the time zone, e.g.

final LocalDateTime result = ZonedDateTime.parse(dateString)
        .withZoneSameInstant(ZoneId.of("Europe/Berlin"))
        .toLocalDateTime();