Java Date Time Java Java API
java.time.Duration
public long toMillis()
package com.logicbig.example.duration;import java.time.Duration;public class ToMillisExample { public static void main(String... args) { Duration d = Duration.ofMinutes(40); System.out.println(d); long m = d.toMillis(); System.out.println(m); }}
PT40M2400000