Java Data Type - 如何将GregorianCalendar转换为ZonedDateTime

import java.time.ZonedDateTime;
import java.util.GregorianCalendar;

public class Main {

  public static void main(String[] args) {
    GregorianCalendar gregorianCalendar = new GregorianCalendar();
    ZonedDateTime d = gregorianCalendar.toZonedDateTime();
    System.out.println(d);

  }
}