JAXB: How can I unmarshal XML without namespaces

An easier way might be to use unmarshalByDeclaredType, since you already know the type you want to unmarshal.

By using

Unmarshaller.unmarshal(rootNode, MyType.class);

you don't need to have a namespace declaration in the XML, since you pass in the JAXBElement that has the namespace already set.

This also perfectly legal, since you are not required to reference a namespace in an XML instance, see http://www.w3.org/TR/xmlschema-0/#PO - and many clients produce XML in that fashion.

Finally got it to work. Note that you have to remove any custom namespace in the schema; here's working sample code:

The schema:

<xsd:schema   xmlns:xsd="http://www.w3.org/2001/XMLSchema"><xsd:element name="customer">   <xsd:complexType>      <xsd:sequence minOccurs="1" maxOccurs="1">         <xsd:element name="name" type="xsd:string" minOccurs="1" maxOccurs="1" />         <xsd:element name="phone" type="xsd:string" minOccurs="1" maxOccurs="1" />      </xsd:sequence>   </xsd:complexType></xsd:element>

XML:

<?xml version="1.0" encoding="UTF-8"?><customer>   <name>Jane Doe</name>   <phone>08154712</phone></customer>

JAXB code:

JAXBContext jc = JAXBContext.newInstance(Customer.class);Unmarshaller u = jc.createUnmarshaller();u.setSchema(schemaInputStream); // load your schema from File or any streamsourceCustomer = u.unmarshal(new StreamSource(inputStream), clazz);  // pass in your XML as inputStream

UPDATE

You can get this to work by introducing an intermediate layer to translate between type and xsi:type. Below is example of using the StAX StreamReaderDelegate to do this for the JAXB unmarshal operation:

package forum7184526;import java.io.FileInputStream;import javax.xml.bind.JAXBContext;import javax.xml.bind.Unmarshaller;import javax.xml.stream.XMLInputFactory;import javax.xml.stream.XMLStreamReader;import javax.xml.stream.util.StreamReaderDelegate;import org.eclipse.persistence.oxm.XMLConstants;public class Demo {    public static void main(String[] args) throws Exception {        XMLInputFactory xif = XMLInputFactory.newFactory();        XMLStreamReader xsr = xif.createXMLStreamReader(new FileInputStream("input.xml"));        xsr = new XsiTypeReader(xsr);        JAXBContext jc = JAXBContext.newInstance(Spec.class);        Unmarshaller unmarshaller = jc.createUnmarshaller();        Spec spec = (Spec) unmarshaller.unmarshal(xsr);    }    private static class XsiTypeReader extends StreamReaderDelegate {        public XsiTypeReader(XMLStreamReader reader) {            super(reader);        }        @Override        public String getAttributeNamespace(int arg0) {            if("type".equals(getAttributeLocalName(arg0))) {                return XMLConstants.SCHEMA_INSTANCE_URL;            }            return super.getAttributeNamespace(arg0);        }    }}

xsi:type is a schema mechanism for specifying the real type of an element (similar to a cast in Java). If you remove the namespace, you are changing the semantics of the document.

• http://blog.bdoughan.com/2010/11/jaxb-and-inheritance-using-xsitype.html

In EclipseLink JAXB (MOXy) we allow you to specify your own inheritance indicator for domain objects using @XmlDescriminatorNode and @XmlDescrimatorValue. We currently do not offer this type of customization for data type properties:

• http://blog.bdoughan.com/2010/11/jaxb-and-inheritance-moxy-extension.html

Based on Blaise's comments (thanks Blaise!) and my research.Here is the solution to my problem. Do you agree with that Blaise, or you have a better way?

package forum7184526;import java.io.FileInputStream;import javax.xml.bind.JAXBContext;import javax.xml.bind.Unmarshaller;import javax.xml.stream.XMLInputFactory;import javax.xml.stream.XMLStreamReader;import javax.xml.stream.util.StreamReaderDelegate;import org.eclipse.persistence.oxm.XMLConstants;public class Demo {public static void main(String[] args) throws Exception {    XMLInputFactory xif = XMLInputFactory.newFactory();    XMLStreamReader xsr = xif.createXMLStreamReader(new FileInputStream("input.xml"));    xsr = new XsiTypeReader(xsr);    JAXBContext jc = JAXBContext.newInstance(Spec.class);    Unmarshaller unmarshaller = jc.createUnmarshaller();    Spec spec = (Spec) unmarshaller.unmarshal(xsr);}private static class XsiTypeReader extends StreamReaderDelegate {    public XsiTypeReader(XMLStreamReader reader) {        super(reader);    }    @Override    public String getAttributeNamespace(int arg0) {        if("type".equals(getAttributeLocalName(arg0))) {            return "http://www.w3.org/2001/XMLSchema-instance";        }        return super.getAttributeNamespace(arg0);    }    @Override    public String getAttributeValue(int arg0) {      String n = getAttributeLocalName(arg0);      if("type".equals(n)) {         String v = super.getAttributeValue(arg0);          return  "xs:"+ v;      }      return super.getAttributeValue(arg0);    }    @Override    public NamespaceContext getNamespaceContext() {      return new MyNamespaceContext(super.getNamespaceContext());    }}private static class MyNamespaceContext implements NamespaceContext {  public NamespaceContext _context;  public MyNamespaceContext(NamespaceContext c){     _context = c;  }  @Override  public Iterator<?> getPrefixes(String namespaceURI) {     return _context.getPrefixes(namespaceURI);  }  @Override  public String getPrefix(String namespaceURI) {     return _context.getPrefix(namespaceURI);  }  @Override  public String getNamespaceURI(String prefix) {     if("xs".equals(prefix)) {        return  "http://www.w3.org/2001/XMLSchema";     }     return _context.getNamespaceURI(prefix);  }}}