Unable to unmarshall XML using Jaxb and XMLPath

Question

I have an XML which needs to be mapped to a Java object i.e. a DTO. My XML has some wrapper elements which don't have any java objects in my DTO.. my XML looks something like this

<UseCaseView>
<FindCandidates>
    <CandidatesRequest>
        <APIRequest>
            <Code>Code</Code>
        </APIRequest>
    </CandidatesRequest>
</FindCandidates>   </UseCaseView>

The "FindCandidates" and "CandidatesRequest" are just wrapper elements and "APIRequest" is again a DTO..

I am using XMLPath like this in my DTO.. My Dto looks like this..

@XmlRootElement(name = "UseCaseView")
 public class FindRequestDTO implements Serializable{

private static final long serialVersionUID = 5528726225975606325L;

private ApiRequestDTO apiRequest;


@XmlPath("FindCandidates/CandidatesRequest/APIRequest")
public ApiRequestDTO getAPIRequest() {
    return apiRequest;
    .........

This is not mapping the APIRequest element to my ApiRequestDTO, if I remove the two wrapper elements and map directly using XMLElement(name = "APIRequest") it works... But I need to ignore the two wrapper elements and construct my DTO.. I have added the Jaxb.properties file with

"javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory"

in my resources folder.

can someone help me to know whats going wrong here..

thanks,

Answer 1

Note: I'm the EclipseLink JAXB (MOXy) lead and a member of the JAXB 2 (JSR-222) expert group.

Below is a complete example that should help.

jaxb.properties

To specify MOXy as your JAXB provider you need to add a file called jaxb.properties with the following entry in the same package as your domain model.

javax.xml.bind.context.factory = org.eclipse.persistence.jaxb.JAXBContextFactory

FindRequestDTO

package forum9881188;

import java.io.*;
import javax.xml.bind.annotation.*;
import org.eclipse.persistence.oxm.annotations.*;

@XmlRootElement(name = "UseCaseView")
public class FindRequestDTO implements Serializable {

    private static final long serialVersionUID = 5528726225975606325L;

    private ApiRequestDTO apiRequest;

    @XmlPath("FindCandidates/CandidatesRequest/APIRequest")
    public ApiRequestDTO getAPIRequest() {
        return apiRequest;
    }

    public void setAPIRequest(ApiRequestDTO apiRequest) {
        this.apiRequest = apiRequest;
    }

}

ApiRequestDTO

package forum9881188;

public class ApiRequestDTO {
}

Demo

package forum9881188;

import javax.xml.bind.*;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(FindRequestDTO.class);

        FindRequestDTO fr = new FindRequestDTO();
        fr.setAPIRequest(new ApiRequestDTO());

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(fr, System.out);
    }

}

Output

<?xml version="1.0" encoding="UTF-8"?>
<UseCaseView>
   <FindCandidates>
      <CandidatesRequest>
         <APIRequest/>
      </CandidatesRequest>
   </FindCandidates>
</UseCaseView>

For More Information

• http://blog.bdoughan.com/2010/07/xpath-based-mapping.html
• http://blog.bdoughan.com/2011/05/specifying-eclipselink-moxy-as-your.html
• https://github.com/bdoughan/blog20110908

---

UPDATE

If for some reason you can't get the MOXy implementation of JAXBContext, you can always use the native APIs to bootstrap. When using the native APIs you do not need the jaxb.properties file:

package forum9881188;

import javax.xml.bind.*;
import org.eclipse.persistence.jaxb.JAXBContextFactory;

public class Demo {

    public static void main(String[] args) throws Exception {
        //JAXBContext jc = JAXBContext.newInstance(FindRequestDTO.class);
        JAXBContext jc = JAXBContextFactory.createContext(new Class[] {FindRequestDTO.class}, null);

        FindRequestDTO fr = new FindRequestDTO();
        fr.setAPIRequest(new ApiRequestDTO());

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(fr, System.out);
    }

}