JAXB - Unmarshal non root element

While generating JAX-WS web service client code using wsimport, it generates Object factory top level method input and output type. This restricts the use to marshal and unmarshal classes which are contained within the top level objects.

More often than not, top level Schema objects are non-domain specific objects like MethodInput/MethodOutput. You can unmarshal them using ObjectFactory

ObjectFactory.java

	@XmlRegistry
	public class ObjectFactory {
	// ...
	private final static QName Query1_QNAME = new QName("urn:Account-WSDL", "query");
	// ...
	}

view raw ObjectFactory.java hosted with ❤ by GitHub

query.xml

	<query xmlns="urn:Account-WSDL">
	<serviceContext>
	<externalUserName>USR</externalUserName>
	</serviceContext>
	<account>
	<accountKey>
	<location>Texas</location>
	<number>6086510</number>
	<code>06</code>
	</accountKey>
	</account>
	</query>

view raw query.xml hosted with ❤ by GitHub

MethodInput.java

	@XmlAccessorType(XmlAccessType.FIELD)
	@XmlType(name = "MethodInput", propOrder = {
	"serviceContext",
	"account"
	})
	public class MethodInput{
	@XmlElement(required = true)
	protected ServiceContext serviceContext;
	@XmlElement(required = true)
	protected Account account;
	// .... omitted for brevity
	}

view raw MethodInput.java hosted with ❤ by GitHub

JaxbUnmarshallerMethodInput.java

	public class JaxbUnmarshallerMethodInput{
	public static void main(String args[]){
	try{
	JAXBContext jc = JAXBContext.newInstance("com.kartikshah.api.account.wsdl");
	Unmarshaller u = jc.createUnmarshaller();
	JAXBElement element = (JAXBElement)u.unmarshal(JaxbUnmarshallerMethodInput.class.getResource("query.xml"));
	MethodInput methodInput = (MethodInput)element.getValue();
	Account account = methodInput.getAccount();
	ServiceContext context = methodInput.getServiceContext();
	}
	catch (Exception e){
	// Removed for brevity
	}
	}
	}

view raw JaxbUnmarshallerMethodInput.java hosted with ❤ by GitHub

But if you want to unmarshal XML chunks of objects contained within those top level object, the same approach does not work, if those generated classes are not included as part of ObjectFactory or they do not have annotation @XmlRootElement on top of that.

account.xml

	<account>
	<accountKey>
	<location>Texas</location>
	<number>6086510</number>
	<code>06</code>
	</accountKey>
	</account>

view raw account.xml hosted with ❤ by GitHub

Option 1

So the obvious option is to add @XmlRootElement to any generated classes that you want to unmarshal directly, but when you are using wsdls are from an external source, idea of updating generated classes breaks the process. 

	@XmlRootElement
	@XmlAccessorType(XmlAccessType.FIELD)
	@XmlType(name = "Account", propOrder = {
	"accountKey", // .. other fields omitted for brevity
	})
	public class Account{
	protected AccountKey accountKey;
	// ...
	}

view raw Account.java hosted with ❤ by GitHub

Option 2

Another option is to pass the child element's Node object to unmarshal 

	public class JaxbUnmarshallerWithDocBuilder {
	public static void main(String args[]){
	try{
	JAXBContext jc = JAXBContext.newInstance("com.kartikshah.api.account.wsdl");
	Unmarshaller u = jc.createUnmarshaller();
	DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
	dbf.setNamespaceAware(true);
	DocumentBuilder db = dbf.newDocumentBuilder();
	Document doc = db.parse(JaxbUnmarshallerWithDocBuilder.class.getResource("account.xml"));
	Node fooSubtree = doc.getFirstChild();
	JAXBElement<Account> account = u.unmarshal( fooSubtree, Account.class);
	}
	catch (Exception e){
	// ... Omitted for brevity
	}
	}

view raw JaxbUnmarshallerWithDocBuilder.java hosted with ❤ by GitHub