java cast duration to long

/**
 * @author lautturi.com
 * Java example: convert duration to long milliseconds in java
 */
import java.util.*;
import java.time.Duration;

public class Lautturi {

	public static void main(String[] args) {

		Duration d = Duration.ofHours(1); 	// 1 hour with java.time
		long millis = d.toMillis();			// 1 hour in milliseconds
		
		System.out.println(millis);
	}
}

output:

3600000