CODEWITHSUNDEEP
javajaxbjersey
Lahniep
Lahniep

Reputation: 729

Jaxb failed to marshall an annotated class

Am using an implementation of MessageBodyWriter to marshall all my objects to a file(XML).

@XmlRootElement(name="root")
@XmlAccessorType( XmlAccessType.FIELD )
class Myclass implements MyInterface{
// some private fields
}

interface MyInterface{
//some methods
}

I have a List<MyClass> objects to save in XML, But when i call Marshaller.marshall(object, outputstream) i got this exception :

[com.sun.istack.SAXException2: unable to marshall type "..MyClass" as an element because it is missing @XmlRootElement annotation]

But the thing is that I do have that annotation on MyClass. Any idea on what is wrong on my marshalling process?

Thanks

Upvotes: 1

Views: 1267

Answers (1)

Michael
Michael

Reputation: 5062

You can marshall a single instance, right?

    MyClass myClass1 = new MyClass();
    myClass1.setField("value");
    JAXB.marshal(myClass1, writer);

But I assume you try to marshall a list? Something like

    List<MyClass> list = new ArrayList<MyClass>();
    list.add(myClass1);
    JAXBContext.newInstance(ArrayList.class).createMarshaller().marshal(list, writer);

If you want to marshall a list in one XML document you need a wrapper class:

@XmlRootElement(name="root")
@XmlAccessorType( XmlAccessType.FIELD )
public class MyWrapper {

    @XmlElement(name="child")
    private List<MyClass> list = new ArrayList<MyClass>();

    public List<MyClass> getList() {
            return list;
    }
...

Then it should work, e.g.:

    MyClass myClass1 = new MyClass();
    myClass1.setField("value");
    MyWrapper wrapper = new MyWrapper();
    wrapper.getList().add(myClass1);
    JAXB.marshal(wrapper, writer);

results in 

    <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
    <root>
         <child>
            <field>value</field>
         </child>
    </root>

Upvotes: 2

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