[java] How do I get milliseconds from epoch (1970-01-01) in Java?

I need to get the number of milliseconds from 1970-01-01 UTC until now UTC in Java.

I would also like to be able to get the number of milliseconds from 1970-01-01 UTC to any other UTC date time.

You can also try

  Calendar calendar = Calendar.getInstance();
  System.out.println(calendar.getTimeInMillis());

getTimeInMillis() - the current time as UTC milliseconds from the epoch

Also try System.currentTimeMillis()

java.time

Using the java.time framework built into Java 8 and later.

import java.time.Instant;

Instant.now().toEpochMilli(); //Long = 1450879900184
Instant.now().getEpochSecond(); //Long = 1450879900

This works in UTC because Instant.now() is really call to Clock.systemUTC().instant()

https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html