jaxb namespace gives unneeded ns2 prefix

Question

I need to generate the namespace into the xml, but this leads to an inconsistent ns2 prefixing that I don't need (I don't have mixed namespaces). I tried several solutions i found with no luck.

package-info.java

    @javax.xml.bind.annotation.XmlSchema(namespace="http://namespace" ,
        elementFormDefault=javax.xml.bind.annotation.XmlNsForm.QUALIFIED,
        xmlns={
        @javax.xml.bind.annotation.XmlNs(namespaceURI="http://namespace", prefix="")
        })

    package hu.xml.create;

POJO

    @XmlRootElement(name = "create", namespace = "http://namespace")
    public class Create{
    ...

marshaller

    public String mashal(Object object) throws JAXBException {
        JAXBContext context = JAXBContext.newInstance(object.getClass());
        Marshaller mar= context.createMarshaller();
        mar.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
    
        StringWriter sw = new StringWriter();

        mar.marshal(object, sw);

        return sw.toString();
}

call

    @RequestMapping("/export/{id}")
    public String export(Model model, @PathVariable(value = "id") Long id) {
        String method = "export";
    
        Create create = new Create(...);
        try {
            String xml = RequestHandler.getInstance().mashal(create);
            model.addAttribute("xml", xml);
        } catch (JAXBException e) {
            e.printStackTrace();
        }
    
        return "export";
}

result

    <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
    <ns2:create xmlns:ns2="http://namespace">
        <ns2:tag>
            <subtag>true</subtag>

How does your desired XML result differ from the actual XML result? — kjhughes, Jan 10 '21 at 18:49
Does this answer your question? [How to set the default namespace using JAXB](https://stackoverflow.com/questions/17478317/how-to-set-the-default-namespace-using-jaxb) — Piotr P. Karwasz, Jan 10 '21 at 20:05
@PiotrP.Karwasz as far as I can tell, that answer contains the same thing I implemented. — Lance Toth, Jan 11 '21 at 10:34
@LanceToth, I noticed later and posted an answer, but forgot to delete the comment. :-) — Piotr P. Karwasz, Jan 11 '21 at 10:36

Piotr P. Karwasz · Accepted Answer · 2021-01-11T18:37:36.053

1

The namespace prefix is needed, since you have elements like <subtag> without a namespace. Once you assign a namespace to them, the ns2 prefix will disappear and JAXB will use a default namespace as your required.

There is also a comment in NamespaceContextImpl#declareNsUri of JAXB RI that states:

// the default prefix is already taken.
// move that URI to another prefix, then assign "" to the default prefix.

Edit: If you cannot get rid of the unqualified elements, you can qualify them with the same namespace as the other elements. This is possible at least with JAXB RI and is equivalent to a <xsd:include> tag:

final Map<String, String> props = Collections.singletonMap(JAXBRIContext.DEFAULT_NAMESPACE_REMAP, "http://namespace");
final JAXBContext ctx = JAXBContext.newInstance(new Class[]{Create.class}, props);

edited Jan 11 '21 at 18:37

answered Jan 10 '21 at 21:32

Piotr P. Karwasz

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the tag in question contains a POJO with identification information that I need to send in different requests, all with their own namespace – Lance Toth Jan 11 '21 at 10:51
If you accept to include those unqualified elements into the main namespace, you can proceed as in the edited answer. The generated XML will, however, not be equivalent to the one you get now. – Piotr P. Karwasz Jan 11 '21 at 18:40
I added what I could to the proper namespace and created subclasses for the class that is used in multiple namespaces. Not an elegant solution, but it works – Lance Toth Jan 15 '21 at 11:01
You can also [play with this gist](https://gist.github.com/ppkarwasz/41300cbcc50d75316903fe426b8be9c3) to check how namespace remapping work. – Piotr P. Karwasz Jan 17 '21 at 19:43

jaxb namespace gives unneeded ns2 prefix

1 Answers1