java - 如何保存 UTC 时间戳？

Question

如何将 ZonedDateTime 转换为 SQL Timestamp 并保留时区信息？我正在尝试获取 UTC 分区时间，将其转换为 Timestamp，然后将其转换回来，但是当我转换为 Timestamp 时，它会丢失时区信息，并且时间戳是使用我的本地时区创建的:

public static void main(String[] args) {

    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("hh:mm a");

    ZonedDateTime zdtUTC = ZonedDateTime.now(ZoneId.of("UTC"));

    ZonedDateTime zdtNY = zdtUTC.withZoneSameInstant(ZoneId.of("America/New_York"));
    ZonedDateTime zdtAZ = zdtUTC.withZoneSameInstant(ZoneId.of("America/Phoenix"));
    ZonedDateTime zdtUK = zdtUTC.withZoneSameInstant(ZoneId.of("Europe/London"));

    System.out.println(formatter.format(zdtUTC) + " in UTC zone");
    System.out.println(formatter.format(zdtNY) + " in New York, NY");
    System.out.println(formatter.format(zdtAZ) + " in Phoenix, AZ");
    System.out.println(formatter.format(zdtUK) + " in London, UK");

    Timestamp timestamp = Timestamp.from(zdtUTC.toInstant());

    LocalDateTime converted = timestamp.toLocalDateTime();
    ZonedDateTime convertedZdt = ZonedDateTime.of(converted, ZoneId.of("UTC"));

    System.out.println(timestamp);

    System.out.println(formatter.format(convertedZdt) + " in UTC zone");

}

06:33 PM in UTC zone
02:33 PM in New York, NY
11:33 AM in Phoenix, AZ
07:33 PM in London, UK
2017-05-07 14:33:06.745
02:33 PM in UTC zone

我需要做什么才能确保 Timestamp 记录使用正确的时区信息？

Answer 1

when I convert to Timestamp, it loses the time zone info and the Timestamp is created using my local time zone

没有。当您将原始 ZonedDateTime zdtUTC 转换为 java.sql.Timestamp 时，您会得到相同的时间点。这可以通过直接格式化并显示 timestamp 值来验证:

Timestamp timestamp = Timestamp.from(zdtUTC.toInstant());  // as before
// verify the timestamp value directly
java.text.SimpleDateFormat sdfUTC = new java.text.SimpleDateFormat("hh:mm a z");
sdfUTC.setCalendar(java.util.Calendar.getInstance(java.util.TimeZone.getTimeZone("UTC")));
System.out.printf("timestamp is %s%n", sdfUTC.format(timestamp));

这将打印与输出第一行相同的值:

08:30 PM in UTC zone
...
timestamp is 08:30 PM UTC

随后转换为 LocalDateTime，然后再转换回 ZonedDateTime，从而“丢失”了时区信息。