Jaxb 中怎么去除空标签

例如 以下空值的节点不需要生成：

<OperationalDateTime>
                <DispatchDateTime>
                    <AircraftDispatchDateTime/>
                </DispatchDateTime>
                <DoorCloseDateTime>
                    <ActualDoorCloseDateTime/>
                </DoorCloseDateTime>
                <OffBlockDateTime>
                    <ActualOffBlockDateTime/>
                </OffBlockDateTime>
                <TakeOffDateTime>
                    <ActualTakeOffDateTime>2019-06-14T08:44:00</ActualTakeOffDateTime>
                </TakeOffDateTime>
                <NextAirportArrivalDateTime>
                    <EstimatedNextAirportArrivalDateTime/>
                    <ActualNextAirportArrivalDateTime/>
                </NextAirportArrivalDateTime>
            </OperationalDateTime>

/**
 * JavaBean转换成xml
 * @param obj
 * @param encoding
 * @return
 */
public static String convertToXml(Object obj, String encoding) {
    String result = null;
    try {
        JAXBContext context = getJaxbContext(obj.getClass());
        Marshaller marshaller = context.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.setProperty(Marshaller.JAXB_ENCODING, encoding);
        StringWriter writer = new StringWriter();
        marshaller.marshal(obj, writer);
        result = writer.toString();
    } catch (Exception e) {
        e.printStackTrace();
    }
    return result;
}

https://blog.csdn.net/qq_26576585/article/details/77689561

我的问题跟你相反，我是想要你这种效果，空值要显示标签，现在显示不出来