javax.xml.bind.UnmarshalException: unexpected elem

问题:

unexpected element (uri:"", local:"Group"). Expected elements are <{}group>

Meet an exception when unmarshalling from xml

JAXBContext jc = JAXBContext.newInstance(Group.class); 
Unmarshaller unmarshaller = jc.createUnmarshaller();
Group group = (User)unmarshaller.unmarshal(new File("group.xml"));

Group class has no any annotation and group.xml just contains data.

Anything can be the cause?

回答1:

It looks like your XML document has the root element "Group" instead of "group". You can:

1. Change the root element on your XML to be "group"
2. Add the annotation @XmlRootElement(name="Group") to the Group classs.

回答2:

You need to put package-info.java in your generated jaxb package. Its content should be something like that

@javax.xml.bind.annotation.XmlSchema(namespace = "http://www.example.org/StudentOperations/")
package generated.marsh;

回答3:

Luckily, the package-info class isn't required. I was able to fix mine problem with iowatiger08 solution.

Here is my fix showing the error message to help join the dots for some.

Error message

javax.xml.bind.UnmarshalException: unexpected element (uri:"http://global.aon.bz/schema/cbs/archive/errorresource/0", local:"errorresource"). Expected elements are <{}errorresource>

Code before fix

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name="", propOrder={"error"})
@XmlRootElement(name="errorresource")
public class Errorresource

Code after fix

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name="", propOrder={"error"})
@XmlRootElement(name="errorresource", namespace="http://global.aon.bz/schema/cbs/archive/errorresource/0")
public class Errorresource

You can see the namespace added to @XmlRootElement as indicated in the error message.

回答4:

After looking more, the root element has to be associated with a schema-namespace as Blaise is noting. Yet, I didnt have a package-info java. So without using the @XMLSchema annotation, I was able to correct this issue by using

@XmlRootElement (name="RetrieveMultipleSetsResponse", namespace = XMLCodeTable.NS1)
@XmlType(name = "ns0", namespace = XMLCodeTable.NS1)
@XmlAccessorType(XmlAccessType.NONE)
public class RetrieveMultipleSetsResponse {//...}

Hope this helps!

回答5:

This is a fix for a pretty niche use case but it gets me each time. If you are using the Eclipse Jaxb generator it creates a file called package-info.

@javax.xml.bind.annotation.XmlSchema(namespace = "blah.xxx.com/em/feed/v2/CommonFeed")
package xxx.blah.mh.domain.pl3xx.startstop;

If you delete this file it will allow a more generic xml to be parsed. Give it a try!

回答6:

I had the same problem.. It helped me, I'm specify the same field names of my classes as the tag names in the xml file (the file comes from an external system).

For example:

My xml file:

<Response>
  <ESList>
     <Item>
        <ID>1</ID>
        <Name>Some name 1</Name>
        <Code>Some code</Code>
        <Url>Some Url</Url>
        <RegionList>
           <Item>
              <ID>2</ID>
              <Name>Some name 2</Name>
           </Item>
        </RegionList>
     </Item>
  </ESList>
</Response>

My Response class:

@XmlRootElement(name="Response")
@XmlAccessorType(XmlAccessType.FIELD)
public class Response {
    @XmlElement
    private ESList[] ESList = new ESList[1]; // as the tag name in the xml file..

    // getter and setter here
}

My ESList class:

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name="ESList")
public class ESList {
    @XmlElement
    private Item[] Item = new Item[1]; // as the tag name in the xml file..

    // getters and setters here
}

My Item class:

@XmlRootElement(name="Item")
@XmlAccessorType(XmlAccessType.FIELD)
public class Item {
    @XmlElement
    private String ID; // as the tag name in the xml file..
    @XmlElement
    private String Name; // and so on...
    @XmlElement
    private String Code;
    @XmlElement
    private String Url;
    @XmlElement
    private RegionList[] RegionList = new RegionList[1];

    // getters and setters here
}

My RegionList class:

@XmlRootElement(name="RegionList")
@XmlAccessorType(XmlAccessType.FIELD)
public class RegionList {
    Item[] Item = new Item[1];

    // getters and setters here
}

My DemoUnmarshalling class:

public class DemoUnmarshalling {
    public static void main(String[] args) {
        try {
            File file = new File("...");

            JAXBContext jaxbContext = JAXBContext.newInstance(Response.class);
            Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
            jaxbUnmarshaller.setEventHandler(
                new ValidationEventHandler() {
                    public boolean handleEvent(ValidationEvent event ) {
                        throw new RuntimeException(event.getMessage(),
                            event.getLinkedException());
                    }
                }
            );

            Response response = (Response) jaxbUnmarshaller.unmarshal(file);

            ESList[] esList = response.getESList();
            Item[] item = esList[0].getItem();
            RegionList[] regionLists = item[0].getRegionList();
            Item[] regionListItem = regionLists[0].getItem();

            System.out.println(item[0].getID());
            System.out.println(item[0].getName());
            System.out.println(item[0].getCode());
            System.out.println(item[0].getUrl());
            System.out.println(regionListItem[0].getID());
            System.out.println(regionListItem[0].getName());

        } catch (JAXBException e) {
            e.printStackTrace();
        }
    }
}

It gives:

1
Some name 1
Some code
Some Url
2
Some name 2

回答7:

Same to me. The name of the mapping class was Mbean but the tag root name was mbean so I had to add the annotation:

@XmlRootElement(name="mbean")
public class MBean { ... }

回答8:

I had the same issue. I added following attributes to <xs:schema..> elementFormDefault="qualified" attributeFormDefault="unqualified"

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns="http://www.example.com/schemas/ArrayOfMarketWithStations"
    targetNamespace="http://www.example.com/schemas/ArrayOfMarketWithStations" 
    elementFormDefault="qualified" attributeFormDefault="unqualified" >

and re-generated java classes by running xjc, which corrected package-info.java.

@javax.xml.bind.annotation.XmlSchema(namespace = "http://www.example.com/schemas/ArrayOfMarketWithStations", elementFormDefault = javax.xml.bind.annotation.XmlNsForm.QUALIFIED)

This fixed the issue for me.

回答9:

If none of the above works, try adding

@XmlRootElement(name="Group") to the Group classs.