Java Unmarshal list of objects with JAXB

问题:

I have XML that looks like the following:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ObjectList>
  <object attributeOne="somedate" attributeTwo="false" attributeThree="id" attributeFour="true"/>
  <object attributeOne="somedate" attributeTwo="false" attributeThree="id" attributeFour="true"/>
  <object attributeOne="somedate" attributeTwo="false" attributeThree="id" attributeFour="true"/>
  <object attributeOne="somedate" attributeTwo="false" attributeThree="id" attributeFour="true"/>
  <object attributeOne="somedate" attributeTwo="false" attributeThree="id" attributeFour="true"/>
</ObjectList>

I have an ObjectList class that looks like the following:

@XmlRootElement
public class ObjectList {

    @XmlElementWrapper(name = "ObjectList")
    @XmlElement(name = "Object")
    private ArrayList<Object> ObjectList;

    public ArrayList<Object> getObjectList() {
        return ObjectList;
    }

    public void setObjectList(ArrayList<Object> objectList) {
        ObjectList = objectList;
    }
}

And an object class that looks like this:

@XmlRootElement(name = "Object")
public class Object {

    Date attributeOne;
    boolean attritbuteTwo;
    String attributeThree;
    boolean attributeFour;

    @XmlAttribute
    public Date getAttributeOne() {
        return attributeOne;
    }
    public void setAttributeOne(Date attributeOne) {
        this.attributeOne = attributeOne;
    }

    @XmlAttribute
    public boolean isAttributeTwo() {
        return attritbuteTwo;
    }
    public void setAttributeTwo(boolean attritbuteTwo) {
        this.AttributeTwo = AttributeTwo;
    }

    @XmlAttribute
    public String getAttributeThree() {
        return attributeThree;
    }
    public void setAttributeThree(String attributeThree) {
        this.attributeThree = attributeThree;
    }

    @XmlAttribute
    public boolean isAttributeFour() {
        return attributeFour;
    }
    public void setAttributeFour(boolean attributeFour) {
        this.attributeFour = attributeFour;
    }
}

When I try to unmarshal the xml into and object using this code:

JAXBContext jaxbContext = JAXBContext.newInstance(ObjectList.class);
Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();

RESTResponse response = getObjects();

ObjectList objects = (ObjectList) unmarshaller.unmarshal(new StringReader(response.getResponseBody()));

I get the following error:

javax.xml.bind.UnmarshalException: unexpected element (uri:"", local:"ObjectList"). Expected elements are <{}Object>,<{}objectList>

EDIT: I just noticed a couple problems I changed the XmlRootElement tag of my ObjectList object to @XmlRootElement(name = "ObjectList") and the XmlRootElement tag of my Object to @XmlRootElement(name = "object). I no longer get the exception, however I get and empty list of objects now.

Any help is much appreciated.

回答1:

Well, it says expected element: Object or objectList (starting with a lowercase "o") but it reads an ObjectList (starting with a uppercase "O")!

回答2:

maybe you should try to change name of your custom class from Object to some other? Or ensure that correct instance of Object is used in ObjectList class