Duplicated field in generated XML using JAXB

Question

This is my scenario. I have a generic class:

public class Tuple extends ArrayList {
  //...
  public Tuple(T ...members) {
    this(Arrays.asLi         


        

Answer 1

You could use the following approach of marking the property @XmlTransient on the parent and @XmlElement on the child:

Parent

package forum7851052;

import java.util.ArrayList;
import java.util.List;

import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;

@XmlRootElement
public class Parent<T> {

    private List<T> item = new ArrayList<T>();

    @XmlTransient
    public List<T> getItem() {
        return item;
    }

    public void setItem(List<T> item) {
        this.item = item;
    }

}

IntegerChild

package forum7851052;

import java.util.List;

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class IntegerChild extends Parent<Integer> {

    @Override
    @XmlElement
    public List<Integer> getItem() {
        return super.getItem();
    }

    @Override
    public void setItem(List<Integer> item) {
        super.setItem(item);
    }

}

StringChild

package forum7851052;

import java.util.List;

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class StringChild extends Parent<String> {

    @Override
    @XmlElement
    public List<String> getItem() {
        return super.getItem();
    }

    @Override
    public void setItem(List<String> item) {
        super.setItem(item);
    }

}

Demo

package forum7851052;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Parent.class, IntegerChild.class, StringChild.class);

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

        IntegerChild integerChild = new IntegerChild();
        integerChild.getItem().add(1);
        integerChild.getItem().add(2);
        marshaller.marshal(integerChild, System.out);

        StringChild stringChild = new StringChild();
        stringChild.getItem().add("A");
        stringChild.getItem().add("B");
        marshaller.marshal(stringChild, System.out);
    }

}

Output

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<integerChild>
    <item>1</item>
    <item>2</item>
</integerChild>
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<stringChild>
    <item>A</item>
    <item>B</item>
</stringChild>

Answer 2

This might be quite old, but its the first result while searching for "JAXB duplicate fields"

Stumbled upon the same problem, this did the trick for me:

@XmlRootElement
@XmlAccessorType(XmlAccessType.NONE) // <-- made the difference
public abstract class ParentClass
{
...
}


@XmlRootElement
public class ChildClass extends ParentClass
{
 ...
}