My client is sending me Long which could be thought as
scala> System.currentTimeMillis
res3: Long = 1441056836609
scala>
How do I convert that into UTC timeStamp?
On Server, we are using Java 8
You can use the Instant class methods.
import java.time.Instant;
import java.time.ZoneOffset;
Instant.ofEpochMilli(<yourmillis>).atOffset(ZoneOffset.UTC).toString();
Your example date would be "2015-08-31T21:33:56.609Z".
Date dateFromTime = new Date(timeInMillis);
That will get a Date object, which you can then spit out in a proper UTC format using
DateFormat dateFormatter = SimpleDateFormat(/*UTC Format String*/, Locale./*Your Locale here*/);
System.out.printf("%s\n", dateFormatter.format(dateFromTime));
Since you are using scala, I would suggest you use the scala way, nscala-time is a very good library
scala> import com.github.nscala_time.time.Imports._
import com.github.nscala_time.time.Imports._
scala> DateTimeZone.setDefault(DateTimeZone.UTC)
scala> new DateTime(1441056836609L)
res1: org.joda.time.DateTime = 2015-08-31T21:33:56.609Z
This is what I am doing
I am using Joda-Time and doing
DateTimeZone.setDefault(DateTimeZone.UTC);
DateTime.now.toString
On client I see it as
Wed, 02 Sep 2015 20:57:34 GMT
and on server I see it as
2015-09-02T20:24:43.594Z
P.S. Don't compare values, they are copied differently, the format is what I wanted to share
来源：https://stackoverflow.com/questions/32320428/how-to-i-convert-long-currenttimeinmillis-to-utc-timestamp