JAXB unmarshalling error: Expected elements are <{ } Root>

Question

I'm reusing existing objects generated elsewhere to unmarshall XML data coming in as a String type.

The object:

/*  3:   */ import java.util.ArrayList;
/*  4:   */ import java.util.List;
/*  5:   */ import javax.xml.bind.annotation.XmlAccessType;
/*  6:   */ import javax.xml.bind.annotation.XmlAccessorType;
/*  7:   */ import javax.xml.bind.annotation.XmlElement;
/*  8:   */ import javax.xml.bind.annotation.XmlRootElement;
/*  9:   */ import javax.xml.bind.annotation.XmlType;
/* 10:   */ 
/* 11:   */ @XmlAccessorType(XmlAccessType.FIELD)
/* 12:   */ @XmlType(name="", propOrder={"policy"})
/* 13:   */ @XmlRootElement(name="MyNodeResponse")
/* 14:   */ public class MyNodeResponse
/* 15:   */ {
/* 16:   */   @XmlElement(name="Policy")
/* 17:   */   protected List<Policy> policy;
/* 18:   */   
/* 19:   */   public List<Policy> getPolicy()
/* 20:   */   {
/* 21:65 */     if (this.policy == null) {
/* 22:66 */       this.policy = new ArrayList();
/* 23:   */     }
/* 24:68 */     return this.policy;
/* 25:   */   }
/* 26:   */ }

My unmarshalling code:

JAXBContext jc = JAXBContext.newInstance(MyNodeResponse.class); 
Unmarshaller unmarshaller = jc.createUnmarshaller();
MyNodeResponse myNodeResponse = (MyNodeResponse)unmarshaller.unmarshal(new InputSource(new ByteArrayInputStream(xmlStringInput.getBytes("utf-8"))));

My input XML:

<ns2:MyNodeResponse 
         xmlns:ns2="mynamespace/2010/10">   
   <ns2:Policy>
   ....more data....
   <ns2:Policy/>
<ns2:MyNodeResponse />

I get the following error when unmarshalling:

unexpected element (uri:"mynamespace/2010/10", local:"MyNodeResponse"). Expected elements are <{}MyNodeResponse>

What exactly does the "{ }" refer to in the error, and how do I unmarshall in a way to match what is present in the input XML and how the object is expecting?

Answer 1

What the Error Message is Saying

What exactly does the "{ }" refer to in the error

In {}MyNodeRespons the {} portion refers to that qualified name not having the namespace URI portion set.

How to Fix It

You need to map the namespace qualification using the package level @XmlSchema annotation:

package-info.java

@XmlSchema(
    namespace = "mynamespace/2010/10",
    elementFormDefault = XmlNsForm.QUALIFIED)
package example;

import javax.xml.bind.annotation.XmlNsForm;
import javax.xml.bind.annotation.XmlSchema;

For More Information

• http://blog.bdoughan.com/2010/08/jaxb-namespaces.html

Answer 2

there is @XmlSchema annotation that defines an attribute called elementFormDefault. In order to put the elements together with their namespaces, this atribute must be set to javax.xml.bind.annotation.XmlNsForm.QUALIFIED. This annotation should be defined in package-info.java