How to persist UserData of Element in JAXB Unmarshal? - jaxb

Question

I unmarshal the Document to object as below.
Before that, when parsing XML, use setUserData to store location information for each element.
class MyJaxbAdapter extends XmlAdapter<Object, SubObject> {}
#Override
public UnattendComponent unmarshal(Object v) throws Exception {
Node node = (Node) v; // ElementNSImpl; It's probably a newly created object. Because It is different from the document object given by ownerDocument as SAXSource.
node.getUserData(...) // return NULL
}
}
Document document = ...;
unmarshaller.setAdapter(new MyJaxbAdapter());
MyXMLObject object = unmarshaller.unmarshal(new DOMSource(document), MyXMLObject.class).getValue();
But I can't get UserData inside XmlAdapter's unmarshal method. Is there any way to persist UserData?
Locator information is stored in the properties of Element as shown below.
#Override
public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
Element el = document.createElementNS(usedNamespaceUri, qName);
// ...
el.setUserData(
ElementUserData.class.getName(),
ElementUserData.builder()
.lineNumber(locator.getLineNumber())
.columnNumber(locator.getColumnNumber())
.build(),
null);
}
I need the Locator information (UserData) stored by the above code in the unmarshal of the XmlAdapter.
However, there is no userdata in the node passed as an argument to unmarshal .
Sample Code:
https://github.com/joseph-jclab/jaxb-question-01

Answer 1

Not entirely sure if this is something you are looking for but providing it as a reference so you might get some idea to proceed further:
Sample XML:
<root>
<name>Batman</name>
<year>2008</year>
</root>
Root.class:
#XmlRootElement(name = "root")
#Data
#XmlAccessorType(XmlAccessType.FIELD)
public class Root {
private String name;
private String year;
#XmlJavaTypeAdapter(CustomAdapter.class)
private String after;
private void afterUnmarshal(Unmarshaller m, Object parent) {
after = name;
}
}
CustomAdapter.class:
public class CustomAdapter extends XmlAdapter<String, String> {
#Override
public String unmarshal(String v) throws Exception {
System.out.println("Within Unmarshal : " + v);
return null;
}
#Override
public String marshal(String v) throws Exception {
System.out.println("Within Marshal : " + v);
return null;
}
}
SampleMain.class:
public class SampleMain {
public static void main(String[] args) throws XMLStreamException, JAXBException {
final InputStream inputStream = Unmarshalling.class.getClassLoader().getResourceAsStream("sample.xml");
final XMLStreamReader xmlStreamReader = XMLInputFactory.newInstance().createXMLStreamReader(inputStream);
final Unmarshaller unmarshaller = JAXBContext.newInstance(Root.class).createUnmarshaller();
unmarshaller.setAdapter(new CustomAdapter());
final Root root = unmarshaller.unmarshal(xmlStreamReader, Root.class).getValue();
System.out.println(root.toString());
Marshaller marshaller = JAXBContext.newInstance(Root.class).createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.TRUE);
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
marshaller.marshal(root, System.out);
}
}
Output:
Root(name=Batman, year=2008, after=Batman)
Within Marshal : Batman
<root>
<name>Batman</name>
<year>2008</year>
</root>