Birth Date with Jaxb and XMLGregorianCalendar

Lots of googling and frustrated colleagues and no solution to represent a simple birth date without minutes and seconds. In short, jaxb always uses XMLGregorianCalendar to represent dates, how to represent the birth date as
1980-01-01
instead of
1980-01-01T00:00:00.000+01:00

This is related to my previous article regarding Fødselsnummer, the Norwegian equivalent of US social security number, extracting birth date from the fødselsnummer.

As this jax-rpc vs jaxb comparison shows, http://www.ibm.com/developerworks/webservices/library/ws-tip-jaxwsrpc2.html, all date related stuff is represented as XMLGregorianCalendar in JAXB. Normally, I work with org.joda.time.DateTime and map to the XMLGregorianCalendar like this.

public static XMLGregorianCalendar dateTimeToXMLGregorianCalendar(
                       DateTime dateTime) throws DatatypeConfigurationException {
  DatatypeFactory dataTypeFactory = DatatypeFactory.newInstance();
  return dataTypeFactory.newXMLGregorianCalendar(dateTime.toGregorianCalendar());
}

What I’ve learned is that it’s of great importance how the XMLGregorianCalendar object is constructed. The solution is simple, but I argue that it’s not very intuitive. I like explicit constructors or static constructors to indicate separate constructors.

public static XMLGregorianCalendar birthDateToXML(DateTime birthDate) throws DatatypeConfigurationException {
        XMLGregorianCalendar xmlGregorianCalendar = DatatypeFactory.newInstance().newXMLGregorianCalendar();
        xmlGregorianCalendar.setDay(birthDate.getDayOfMonth());
        xmlGregorianCalendar.setMonth(birthDate.getMonthOfYear());
        xmlGregorianCalendar.setYear(birthDate.getYear());
        return xmlGregorianCalendar;
}

now you may use xsd:date to represent it, instead of xsd:dateTime, in order to improve compatibility with older web services implementing older jaxb versions (with java.util.calendar instead of XMLGregorianCalendar) and/or JAX-RPC.