Question

How do I format a javax.time.Instant as a string in the local time zone? The following translates a local Instant to UTC, not to the local time zone as I was expecting. Removing the call to toLocalDateTime() does the same. How can I get the local time instead?

public String getDateTimeString( final Instant instant )
{
    checkNotNull( instant );
    DateTimeFormatterBuilder builder = new DateTimeFormatterBuilder();
    DateTimeFormatter formatter = builder.appendPattern( "yyyyMMddHHmmss" ).toFormatter();
    return formatter.print( ZonedDateTime.ofInstant( instant, TimeZone.UTC ).toLocalDateTime() );
}

Note: We’re using the older version 0.6.3 of the JSR-310 reference implementation.

Answer 1

The question was about version 0.6.3 of the JSR-310 reference implementation, long before the arrival of Java 8 and the new date library

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I gave up on JSR-310 classes DateTimeFormatter and ZonedDateTime and instead resorted to old fashioned java.util.Date and java.text.SimpleDateFormat:

public String getDateTimeString( final Instant instant )
{
    checkNotNull( instant );
    DateFormat format = new SimpleDateFormat( "yyyyMMddHHmmss" );
    Date date = new Date( instant.toEpochMillisLong() );
    return format.format( date );
}