Deserialization of class inheritance depends on attributes order

When I try to deserialize this xml, XmlMapper creates empty list of action-elements:

<widget id="4" type="Transition">
    <attributes>
        <event/>
        <action name="a"/>
        <action name="b"/>
        <code/>
        <guard/>
    </attributes>
</widget>

But if I put the type attribute on the first position, the list contains 2 elements.

Parent class Widget:

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type", defaultImpl = TransitionWidget.class)
@JsonSubTypes({
        @JsonSubTypes.Type(value = StateWidget.class, name = "State"),
        @JsonSubTypes.Type(value = TransitionWidget.class, name = "Transition")
})
public abstract class Widget {
    private Integer id;

    protected Widget(Integer id) {
        this.id = id;
    }

    @JacksonXmlProperty(isAttribute = true)
    public Integer getId() {
        return id;
    }
}

Child class TransitionWidget:

@JacksonXmlRootElement(localName = "widget")
public class TransitionWidget extends Widget {
    private final TransitionAttributes attributes;

    @JsonCreator
    public TransitionWidget(@JsonProperty("id") Integer id, @JsonProperty("attributes") TransitionAttributes attributes) {
        super(id);
        this.attributes = attributes;
    }

    @JacksonXmlProperty(localName = "attributes")
    public TransitionAttributes getAttributes() {
        return attributes;
    }
}

And its inner class:

@JacksonXmlRootElement(localName = "attributes")
public class TransitionAttributes {
    private Event event;
    private List<Action> actions;
    private String code;
    private String guard;

    @JacksonXmlProperty(localName = "action")
    @JacksonXmlElementWrapper(useWrapping = false)
    public List<Action> getActions() {
        return actions;
    }
}

Method “getActions” also returns empty list, when type-attribute of widget is missing while defaultImpl is specified.

This is checked with Jackson 2.8.8 and 2.9.0.pr3.

[cowtowncoder]

Figured out a way to solve the specific problem in this case.

[cowtowncoder]

@jimirocks Np. Glad I went ahead and problem turned out relatively easy to fix.