Java 8 时区转换

2022-09-04 07:59:55

在Java 8中,我想将日期时间从UTC转换为ACST(UTC + 9:30)。

输入 -> 2014-09-14T17:00:00+00:00

输出> 2014-09-15 02:30:00

String isoDateTime = "2014-09-14T17:00:00+00:00";
LocalDateTime fromIsoDate = LocalDateTime.parse(isoDateTime, DateTimeFormatter.ISO_OFFSET_DATE_TIME);

ZoneOffset offset = ZoneOffset.of("+09:30");
OffsetDateTime acst = OffsetDateTime.of(fromIsoDate, offset);
System.out.println(acst.toString()); // 2014-09-14T17:00+09:30
System.out.println(acst.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME)); // 2014-09-14T17:00:00+09:30

为什么不执行偏移?


答案 1

尝试:

String isoDateTime = "2014-09-14T17:00:00+00:00";
ZonedDateTime fromIsoDate = ZonedDateTime.parse(isoDateTime);
ZoneOffset offset = ZoneOffset.of("+09:30");
ZonedDateTime acst = fromIsoDate.withZoneSameInstant(offset);

System.out.println("Input:  " + fromIsoDate);
System.out.println("Output: " + acst.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME)); 

输出:

Input:  2014-09-14T17:00Z
Output: 2014-09-15T02:30:00+09:30

OffsetDateTime

虽然通常最好按上图所示使用,但您可以使用以下命令执行相同的转换:ZonedDateTimeOffsetDateTime

String isoDateTime = "2014-09-14T17:00:00+00:00";
OffsetDateTime fromIsoDate = OffsetDateTime.parse(isoDateTime);
ZoneOffset offset = ZoneOffset.of("+09:30");
OffsetDateTime acst = fromIsoDate.withOffsetSameInstant(offset);

答案 2

对上述内容略有改进。避免硬编码偏移。此外,还要注意夏令时。

public static LocalDateTime convertTo(LocalDateTime dateTime, String timeZone) {
    ZoneId zone = ZoneId.of(timeZone);
    ZonedDateTime zdt = dateTime.atZone(zone);
    ZoneOffset offset = zdt.getOffset();
    return dateTime.plus(offset.getTotalSeconds(), ChronoUnit.SECONDS);
}

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