[java] JAXB Exception: Class not known to this context

When I call a particular restful service method, which is built using CXF, I get the following error, anyone know why and how to resolve it?

JAXBException occurred : class com.octory.ws.dto.ProfileDto nor any of its super class is known to this context...

Following are the service method and relevant DTOs:

public class Service {
   public Response results() {
   Collection<ProfileDto> profilesDto = new ArrayList<ProfileDto>();
   ...
   SearchResultDto srd = new SearchResultDto();
   srd.setResultEntities(profilesDto); // Setting profilesDto collection as resultEntities
   srd.setResultSize(resultSize);
   return Response.ok(srd).build();
   }
}

SearchResultDto:

@XmlRootElement(name="searchResult")
public class SearchResultDto {
    private Collection resultEntities;
    private int resultSize;

    public SearchResultDto() { }

    @XmlElementWrapper(name="resultEntities")
    public Collection getResultEntities() {
        return resultEntities;
    }

    public void setResultEntities(Collection resultEntities) {
        this.resultEntities = resultEntities;
    }

    public int getResultSize() {
        return resultSize;
    }

    public void setResultSize(int resultSize) {
        this.resultSize = resultSize;
    }
}

ProfileDto:

@XmlRootElement(name="profile")
public class ProfileDto {
    ...
    ...
    public ProfileDto() { }
    ...
}

Fixed it by setting the class name to the property "classesToBeBound" of the JAXB marshaller:

<bean id="jaxbMarshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
        <property name="classesToBeBound">
          <list>
                <value>myclass</value>
          </list>
        </property>
</bean>

I had the same exception on Tomcat.. I found another problem - when i use wsimport over maven plugin to generate stubs for more then 1 WSDLs - class ObjectFactory (stubs references to this class) contains methods ONLY for one wsdl. So you should merge all methods in one ObjectFactory class (for each WSDL) or generate each wsdl stubs in different directories (there will be separates ObjectFactory classes). It solves problem for me with this exception..J

I had this error because I registered the wrong class in this line of code:

JAXBContext context = JAXBContext.newInstance(MyRootXmlClass.class);

I had the same problem with spring boot. It resolved when i set package to marshaller.

@Bean
public Jaxb2Marshaller marshaller() throws Exception
{
    Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
    marshaller.setPackagesToScan("com.octory.ws.dto");
    return marshaller;
}

@Bean
public WebServiceTemplate webServiceTemplate(final Jaxb2Marshaller marshaller)   
{
    WebServiceTemplate webServiceTemplate = new WebServiceTemplate();
    webServiceTemplate.setMarshaller(marshaller);
    webServiceTemplate.setUnmarshaller(marshaller);
    return webServiceTemplate;
}

This error message happens either because your ProfileDto class is not registered in the JAXB Content, or the class using it does not use @XmlSeeAlso(ProfileDto.class) to make processable by JAXB.

About your comment:

I was under the impression the annotations was only needed when the referenced class was a sub-class.

No, they are also needed when not declared in the JAXB context or, for example, when the only class having a static reference to it has this reference annotated with @XmlTransient. I maintain a tutorial here.