How can we convert Timestamp datatype in Java to UTC timezone in JPA entity Java?

Question

We are using PO class to represent the sql DB and using Java JPA entity.In that class, we have one column as a field currentTime with Timestamp datatype and @version annotation from JPA.

@Version
private Timestamp currentTime;

whenever the entity gets updated, currentTime is updated with the latest time.

currentTime = new Timestamp(0); //this will create the new timestamp with current time.

but it's currently taking the time from the server. I want to convert this time to UTC format before saving it to DB.

Anyone can help how can I convert the time to UTC time?

Answer 1

I had a similar problem when I needed to parse the time from server but I needed to convert this time to UTC format before storing this information int MySQL DB. This was my solution:

     Instant dateConverted = LocalDateTime
                            .parse(dateTime, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss", Locale.ENGLISH))
                            .atZone(ZoneId.of("Europe/Bratislava")).toInstant();

     long epochTime = dateConverted.toEpochMilli() / 1000L;

Where dateTime is a String variable containing the date and time from server And I have used DateTimeFormatter to format my time to appropriate format. At the end I have added the zoneID of my timeZone and converted it to Instant

And at the end I have converted to seconds

Answer 2

试试下面的代码，

currentTime = Timestamp.valueOf(LocalDateTime.ofInstant(Instant.now(), ZoneOffset.UTC));

Answer 3

       SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm", Locale.getDefault());
       sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
    String localTime = sdf.format(new Date(your_time_stamp));
    Date date = new Date();
    try {
        date = sdf.parse(localTime);//get local date
    } catch (ParseException e) {
        e.printStackTrace();
    }