How to get milliseconds from LocalDateTime in Java 8

To get the milliseconds from a LocalDateTime object in Java 8, you can use the toInstant method and the toEpochMilli method.

Here's an example of how you can use these methods to get the milliseconds from a LocalDateTime object:

import java.time.LocalDateTime;
import java.time.ZoneId;

public class Main {
  public static void main(String[] args) {
    LocalDateTime localDateTime = LocalDateTime.now();
    long milliseconds = localDateTime.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli();
    System.out.println(milliseconds);
  }
}

This code defines a LocalDateTime object and gets the current time using the now method. It then uses the atZone method to convert the LocalDateTime to a ZonedDateTime object, the toInstant method to convert the ZonedDateTime to an Instant object, and the toEpochMilli method to convert the Instant to a long value representing the number of milliseconds since the epoch (midnight, January 1, 1970).

I hope this helps! Let me know if you have any questions.