Question

I’m using JAXB 2.1 and I’m confused by the XML output I’m seeing. Below I have two child classes that extend the same parent. When marshalled and viewed as XML in a browser using REST, Child class 1 (GeoLocationDecodedPayload) always has a root element of geoLocationDecodedPayload as expected. For some reason child class 2 (AltitudeDecodedPayload) doesn’t have altitudeDecodedPayload as its root element which is unexpected as its specified in its @XMLRootElement annotation. The XML output shows the super class (GeoPayload) @XMLRootElement of geoPayload. Any ideas why these two class act differently?

child class 1:

package com.api.model.vo.decoder;

import java.io.Serializable;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
import com.api.util.decoder.DecoderConstants;

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "geoLocationDecodedPayload")
public class GeoLocationDecodedPayload extends GeoPayload implements Serializable {

   public GeoLocationDecodedPayload() {}

}

child class 2:

package com.api.model.vo.decoder;

import java.io.Serializable;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
import com.api.util.decoder.DecoderConstants;

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "altitudeDecodedPayload")
public class AltitudeDecodedPayload extends GeoPayload implements Serializable {

    public AltitudeDecodedPayload() {}

}

parent class:

package com.api.model.vo.decoder;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "geoPayload")
public class GeoPayload {

    public GeoPayload() {}
}

Answer 1

I had forgot to include AltitudeDecodedPayload.class in the below. This fixed my issue.

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name="payloadResponse")
public class PayloadResponse extends AbstractResponse{
    @XmlElementWrapper(name="decodedPayloads")
    @XmlElementRefs({
        @XmlElementRef(type=GeoPayload.class),
        @XmlElementRef(type=GeoLocationDecodedPayload .class),
        @XmlElementRef(type=AltitudeDecodedPayload .class)