java - 无法将类型编码为 XML 元素，因为缺少 @XmlRootElement 注释

Question

我想将对象编码为 XML。

但是，它失败并出现异常:

javax.xml.bind.MarshalException
 - with linked exception:
[com.sun.istack.SAXException2: unable to marshal type "FreightOfferDetail" as an element because it is missing an @XmlRootElement annotation]
    at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:331)
    at com.sun.xml.bind.v2.runtime.MarshallerImpl.marshal(MarshallerImpl.java:257)
    at javax.xml.bind.helpers.AbstractMarshallerImpl.marshal(AbstractMarshallerImpl.java:96)
    at com.wktransportservices.fx.test.util.jaxb.xmltransformer.ObjectTransformer.toXML(ObjectTransformer.java:27)
    at com.wktransportservices.fx.test.sampler.webservice.connect.FreightOfferToConnectFreight.runTest(FreightOfferToConnectFreight.java:59)
    at org.apache.jmeter.protocol.java.sampler.JavaSampler.sample(JavaSampler.java:191)
    at org.apache.jmeter.threads.JMeterThread.process_sampler(JMeterThread.java:429)
    at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:257)
    at java.lang.Thread.run(Thread.java:662)
Caused by: com.sun.istack.SAXException2: unable to marshal type "FreightOfferDetail" as an element because it is missing an @XmlRootElement annotation
    at com.sun.xml.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:244)
    at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeRoot(ClassBeanInfoImpl.java:303)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsRoot(XMLSerializer.java:490)
    at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:328)

事实上，这个注解是存在的(对于父类和交付类):

@XmlRootElement(name = "Freight_Offer")
@XmlAccessorType(XmlAccessType.FIELD)
@JsonIgnoreProperties(ignoreUnknown = true)
@JsonInclude(JsonInclude.Include.NON_EMPTY)
public class FreightOffer {
    @JsonIgnore
    @XmlTransient
    private String freightId;
    private String id;

    private String externalSystemId;

    private AddressLocation pickUp;

    private AddressLocation delivery;

    private FreightDescription freightDescription;

    private ListContacts contacts;

    private Customer customer;

    private ListSla slas;

    private String pushId;

    private CompanyProfile company;

    private Route route;

    private String href;

    private Lifecycle lifecycle;

    private Visibility visibility;

    private Boolean unfoldedVXMatching;
    // getters / setters

子类:

@XmlAccessorType(XmlAccessType.PROPERTY)
public class FreightOfferDetail extends FreightOffer {

    private List<Contact> contact;

    @XmlElement(name = "contacts")
    @JsonProperty("contacts")
    public List<Contact> getContact() {
        return contact;
    }

    public void setContact(List<Contact> contact) {
        this.contact = contact;
    }

正是在这个方法 toXML() 上失败了:

public class ObjectTransformer<T> implements Transformer<T> {

    protected final JAXBContext context;
    protected final Marshaller marshaller;

    protected final int okStatusCode = 200;
    protected final String okSubErrorCode = "OK";

    public ObjectTransformer(JAXBContext context) throws JAXBException {
        this.context = context;
        marshaller = context.createMarshaller();
        marshaller.setProperty("jaxb.encoding", "UTF-8");
        marshaller.setProperty("jaxb.formatted.output", Boolean.TRUE);
    }

    public String toXML(T object) throws JAXBException {
        StringWriter writer = new StringWriter();
        marshaller.marshal(object, writer);
        String xmlOffer = writer.toString();
        return xmlOffer;
    }

它应该有效，但它不应该。

我找不到这里遗漏或错误的内容。

更新:

这是测试的片段:

public SampleResult runTest(JavaSamplerContext context) {
    AbstractSamplerResults results = new XMLSamplerResults(new SampleResult());
    results.startAndPauseSampler();

    if (failureCause != null) {
        results.setExceptionFailure("FAILED TO INSTANTIATE connectTransformer", failureCause);
    } else {
        FreightOfferDTO offer = null;
        FreightOffer freightOffer = null;
        try {
            results.resumeSampler();            

            RouteInfo routeDTO = SamplerUtils.getRandomRouteFromRepo(context.getIntParameter(ROUTES_TOUSE_KEY));

            offer = FreightProvider.createRandomFreight(routeDTO, createUserWithLoginOnly(context));

            freightOffer = connectTransformer.fromDTO(offer);
            String xmlOfferString = connectTransformer.toXML(freightOffer); // <- it fails here.

我从 CSV 文件中获取日期并转换为 DTO 对象。这个方法返回给我FreightOfferDetail.

这里是这个方法的片段:

public FreightOfferDetail freightFromDTO(FreightOfferDTO freightDTO, boolean fullFormat){
    FreightOfferDetail freight = new FreightOfferDetail();

    freight.setFreightId(freightDTO.getIds().getAtosId());
    freight.setId(freightDTO.getIds().getFxId());
    // ...

在这种情况下，如何将对象编码到 XML 文件？

Answer 1

public String toXML(T object) throws JAXBException {
  StringWriter stringWriter = new StringWriter();

  JAXBContext jaxbContext = JAXBContext.newInstance(T.class);
  Marshaller jaxbMarshaller = jaxbContext.createMarshaller();

  // format the XML output
  jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

  QName qName = new QName("com.yourModel.t", "object");
  JAXBElement<T> root = new JAXBElement<Bbb>(qName, T.class, object);

  jaxbMarshaller.marshal(root, stringWriter);

  String result = stringWriter.toString();
  LOGGER.info(result);
  return result;
}

这是我在没有@XmlRootElement 的情况下必须编码/解码时使用的文章:http://www.source4code.info/2013/07/jaxb-marshal-unmarshal-with-missing.html

祝一切顺利:)