Same code of date parsing show different results depending if I am using Java 8 or Java 11.
Here are a code sample to reproduce the problem :
public static void main(String[] args) {
DateTimeFormatterBuilder dfBuilder = new DateTimeFormatterBuilder()
.appendPattern("uuuu-M-d")
.optionalStart()
.optionalStart().appendLiteral(' ').optionalEnd()
.optionalStart().appendLiteral('T').optionalEnd()
.appendValue(ChronoField.HOUR_OF_DAY)
.optionalStart()
.appendLiteral(':')
.appendValue(ChronoField.MINUTE_OF_HOUR)
.optionalStart()
.appendLiteral(':')
.appendValue(ChronoField.SECOND_OF_MINUTE)
.optionalStart()
.appendFraction(ChronoField.NANO_OF_SECOND, 1, 9, true)
.optionalEnd()
.optionalEnd()
.optionalEnd()
.appendPattern("[XXXXX][XXXX][XXX][XX][X]")
.optionalEnd();
DateTimeFormatter df = dfBuilder.toFormatter(Locale.FRANCE).withZone(ZoneId.of("Europe/Paris"));
TemporalAccessor temporalAccessor = df.parse("1970-01-01T00:00:00.00Z");
Instant instantTime = Instant.from(temporalAccessor);
long epochTimestamp = instantTime.getEpochSecond();
System.out.println(epochTimestamp);
}
On java 8 the output is -3600.
While on Java 11 the output is 0 (which is the value I am expecting).
From my analysis the origin is the use of "withZone()" method, if I remove it, it works as expected for dates that contains zone data.
But at the same this behavior is not the same on all DateTimeFormatter : for example if I use this formatter :
DateTimeFormatter formatter = new DateTimeFormatterBuilder()
.appendPattern("yyyy-MM-dd HH:mm:ss")
.appendFraction(ChronoField.MICRO_OF_SECOND, 0, 6, true)
.optionalStart()
.appendZoneId()
.optionalEnd()
.toFormatter()
.withZone(ZoneId.of("Europe/Paris"));
The zoneId is well taken into account in case present inside the date (despite the fact "withZone() is called). So I suppose there is something wrong with the first formatter and that a default behavior on Java 11 helps it to work as expected on Java 11 but not on Java 8 ? Also I precise that my goal is to have it works on Java 8.
