Convert OffsetDateTime to UTC Timestamp

Question

I have an java.time.OffsetDateTime which I would like to convert to a java.sql.Timestamp . Since Timestamp doesn't store any offset information, I am going to store all dates/times in the database as UTC.

How do I convert the OffsetDateTime to a Timestamp which is in UTC?

EDIT:

I believe this is the answer but it seems are rather convoluted way to covert to UTC:

OffsetDateTime dateTime = OffsetDateTime.now();
Timestamp timestamp = Timestamp.valueOf(dateTime.atZoneSameInstant(ZoneId.of("Z")).toLocalDateTime());

Answer 1

This would be a way to do the conversion and ensure UTC is used. That I think is a little cleaner than solution proposed using the epoch seconds.

Timestamp test = Timestamp.valueOf(entityValue.atZoneSameInstant(ZoneOffset.UTC).toLocalDateTime());

Answer 2

Another solution would be:

Timestamp.valueOf(LocalDateTime.ofInstant(dateTime.toInstant(), ZoneOffset.UTC));

It converts the dateTime to UTC, strips the timezone information and then converts the result to a Timestamp . It is still convoluted but IMHO it's a bit cleaner.

Just using toInstance() or toEpochSeconds() will adjust the result with the offset provided.

The following shows the test results from this and the other answers:

OffsetDateTime dateTime = 
    OffsetDateTime.of(2015, 10, 23, 12, 44, 43, 0, ZoneOffset.UTC);
    // OffsetDateTime.of(2015, 10, 23, 12, 44, 43, 0, ZoneOffset.ofHours(-5));

err.println("dateTime            = " 
    + dateTime
);

err.println("as LocalDateTime    = " 
    + dateTime.toLocalDateTime()
);

err.println("as timestamp (mine) = " 
    + Timestamp.valueOf(LocalDateTime.ofInstant(dateTime.toInstant(), ZoneOffset.UTC))
);

err.println("@Cheetah (correct)  = " 
    + Timestamp.valueOf(dateTime.atZoneSameInstant(ZoneId.of("Z"))
        .toLocalDateTime())
);

err.println("@Notso (wrong)      = " 
    + Timestamp.from(dateTime.toInstant())
);

err.println("@Glorfindel (wrong) = " 
    + new Timestamp(1000 * dateTime.toEpochSecond())
);

which gives the following results (my timezone is CET) :

(with ZoneOffset.UTC)
dateTime            = 2015-10-23T12:44:43Z
as LocalDateTime    = 2015-10-23T12:44:43
as timestamp (mine) = 2015-10-23 12:44:43.0
@Cheetah (correct)  = 2015-10-23 12:44:43.0
@Notso (wrong)      = 2015-10-23 14:44:43.0
@Glorfindel (wrong) = 2015-10-23 14:44:43.0

(with ZoneOffset.ofHours(-5))
dateTime            = 2015-10-23T12:44:43-05:00
as LocalDateTime    = 2015-10-23T12:44:43
as timestamp (mine) = 2015-10-23 17:44:43.0
@Cheetah (correct)  = 2015-10-23 17:44:43.0
@Notso (wrong)      = 2015-10-23 19:44:43.0
@Glorfindel (wrong) = 2015-10-23 19:44:43.0

(The version from Notso above was before his edit of Feb 17 2016)

Answer 3

使用.toEpochSecond()从参考日期（以UTC为单位.toEpochSecond()获取秒数，乘以1000并将其传递给Timestamp构造函数（因为它需要毫秒）。

new Timestamp(1000 * offsetDateTime.toEpochSecond());