How to use XMLGregorianCalendar

How to convert a Date to an XMLGregorianCalendar

GregorianCalendar c = new GregorianCalendar();
c.setTime(new Date());
XMLGregorianCalendar xmlDate = DatatypeFactory.newInstance().newXMLGregorianCalendar(c);

How to convert an XMLGregorianCalendar to a Date

Date date = xmlDate.toGregorianCalendar().getTime();