Conversion between Date and LocalDateTime

I do not know why the conversion between Date and LocalDate is so complicated and ugly. But I have to do it increasingly often. So this note is on how to convert between Date, LocalDate and milliseconds.

public static void main(String[] args) {
    // convert from Date to LocalDateTime
    Date d = new Date();
    LocalDateTime ld = LocalDateTime.ofInstant(d.toInstant(), ZoneId.systemDefault());

    // convert from LocalDateTime to Date  
    Date d2 = Date.from(ld.atZone(ZoneId.systemDefault()).toInstant());
    System.out.println("date : " + d);
    System.out.println("ldate: " + ld);
    System.out.println("date2: " + d2);

    // compare milliseconds
    System.out.println("millis : " + d.getTime());
    System.out.println("lmillis: " + ld.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli());
}

The output is:

date : Sat Feb 17 14:41:00 CET 2018
ldate: 2018-02-17T14:41:00.941
date2: Sat Feb 17 14:41:00 CET 2018

millis : 1518874860941
lmillis: 1518874860941