How to get difference between two dates?

1. Time diffInMilli = java.time.Duration.between(dateTime1, dateTime2).toMillis();
2. Date diffInMilli = java.time.Duration.between(dateTime1, dateTime2).toMillis();
3. long diffInMilli = java.time.Duration.between(dateTime1, dateTime2).toMillis();
4. long diffInMilli = java.time.difference(dateTime1, dateTime2).toMillis();
5. None of these

Java 8 provides a method called between which provides Duration between two times.