JAXB Nesting a Collection

Question

I'm having troubles mapping a Collection of JAXB object within another JAXB object, anyone see the issue with my structure below? I get an empty formerUsers ArrayList using the following code:

 String test="<SSO-Request><User-Id>3119043033121014002</User-Id><Former-User-Ids><User-Id>3119043033121014999</User-Id><User-Id>3119043033121014555</User-Id></Former-User-Ids></SSO-Request>";
        SSORequest ssoRequest=null;
        try{
            JAXBContext jaxbContext = JAXBContext.newInstance(SSORequest.class);
            Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
            ssoRequest = (SSORequest) unmarshaller.unmarshal(new StringReader(test));
        }
        catch(Exception e){
            e.printStackTrace();
        }

    @XmlAccessorType(XmlAccessType.FIELD)
    @XmlRootElement(name="SSO-Request")
    public class SSORequest {
        @XmlElement(name="User-Id")
        String userId;
        @XmlElementWrapper(name="Former-User-Ids")
        List<FormerUser> formerUsers;
    }

    @XmlAccessorType(XmlAccessType.FIELD)
    @XmlRootElement(name="Former-User-Ids")
    public class FormerUser {
    @XmlElement(name="User-Id")
    String userId;
}

score 2 · Accepted Answer · answered Mar 28 '11 at 13:15

You're over-complicating your mapping, this is all you need:

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name="SSO-Request")
public class SSORequest {

    @XmlElement(name="User-Id")
    String userId;

    @XmlElementWrapper(name="Former-User-Ids")
    @XmlElement(name="User-Id")
    List<String> formerUserIds;
}

score 1 · Answer 2 · answered Mar 28 '11 at 13:31

You should either change your mapping as skaffman proposed, or you should change the xml:

<SSO-Request><User-Id>3119043033121014002</User-Id><Former-User-Ids><Former-User><User-Id>3119043033121014999</User-Id></Former-User><Former-User><User-Id>3119043033121014555</User-Id></Former-User></Former-User-Ids></SSO-Request>

and change the name of the the FormerUser xml element:

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name="Former-User")
public class FormerUser {
    @XmlElement(name="User-Id")
    String userId;
 }

score 0 · Answer 3 · edited May 23 '17 at 11:47

If the property should be List<FormerUser> then you will need a way to tell JAXB what the ID corresponds to. If the data for FormerUsers will occur in the document then you can use @XmlID and @XmlIDREF for this mapping:

http://bdoughan.blogspot.com/2010/10/jaxb-and-shared-references-xmlid-and.html

If the data for FormerUsers will occur outside the document, then you can use the strategy I described in the answer below:

Using JAXB to cross reference XmlIDs from two XML files

JAXB Nesting a Collection

3 Answers3