Unable to marshal type as XML element because @XmlRootElement annotation is missing

问题

I want to marshal object to XML.

However, it fails with exception:

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)

In fact, this annotation is present (for parent and delivered class):

@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

Child class:

@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;
    }

It fails exactly at this method toXML():

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;
    }

It should work, but it shouldn't.

I couldn't find what is missed or wrong here.

UPDATE:

Here is snippet from test:

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.

I take the date from CSV file and converting to DTO object. This method returns to me FreightOfferDetail.

Here is snippet from this method:

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

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

How to marshal object to XML file, at this case?

回答1:

Note that the error message talks about FreightOfferDetail, not FreightOffer.

Based on that, I would expect that somewhere (outside the provided code), you're asking a Detail to be marshalled.

If you want to be able to do that (with JAXB?) you need to annotate that class as well with the XmlRootElement annotation.

回答2:

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;
}

Here is the article I use when I have to marshal/unmarshal without @XmlRootElement: http://www.source4code.info/2013/07/jaxb-marshal-unmarshal-with-missing.html

All the best hope it helps :)

回答3:

You can use the ObjectFactory class to workaround for the classes which doesn't have the @XmlRootElement. ObjectFactory has overloaded methods.

Method:1 It does simple creation of the object and

Method:2 It will wrap the object with @JAXBElement.

Always to use Method:2 to avoid javax.xml.bind.MarshalException - with linked exception missing an @XmlRootElement annotation

Method:1

public GetCountry createGetCountry() {
        return new GetCountry();
    }

Method:2

 @XmlElementDecl(namespace = "my/name/space", name = "getCountry")
 public JAXBElement<GetCountry> createGetCountry(GetCountry value) {
        return new JAXBElement<GetCountry>(_GetCountry_QNAME, GetCountry.class, null, value);
    }

for more information follow this stackoverflow-question

Hope this will be helpful...

回答4:

When creating the Java-Objects from the WSDL with the apache-cxf maven-plugin, using sth. like:

<plugin>
    <groupId>org.apache.cxf</groupId>
    <artifactId>cxf-codegen-plugin</artifactId>
    ...
</plugin> 

There will be a automatically generated ObjectFactory.

When configuring your Exception in Java you can use this generated ObjectFactory for returning the fault. The important step is to return a JAXBElement<YourSoapFault> in the getFaultInfo() method of your exception.

@WebFault(name = "YourSoapFault",
        targetNamespace = "ns://somenamespace")
public class SomeWebServiceException extends RuntimeException {
    private final YourSoapFault fault;

    public SomeWebServiceException(String message, YourSoapFault fault) {
        super(message);
        this.fault = fault;
    }

    public SomeWebServiceException(String message, YourSoapFault fault, Throwable e) {
        super(message, e);
        this.fault = fault;
    }

    public JAXBElement<YourSoapFault> getFaultInfo() {
        return new ObjectFactory().createYourSoapFault(fault);
    }

}

来源：https://stackoverflow.com/questions/37050316/unable-to-marshal-type-as-xml-element-because-xmlrootelement-annotation-is-miss