Inheritance in XML Schema definition (XSD) for Java objects

Question

Hi,

I need to create an XML schema definition (XSD) that describes Java objects.

I was wondering how to do this when the objects in question inherit from a common base class with a type parameter.

public abstract class Rule<T> { ... }

public abstract class TimeRule extends Rule<XTime> { ... }

public abstract class LocationRule extends Rule<Location> { ... }

public abstract class IntRule extends Rule<Integer> { ... }

....

(where XTime and Location are custom classes defined elsewhere)

How would I go about constructing an XSD that such that I can have XML nodes that represent each of the subclasses of Rule<T> - without the XSD for each of them repeating their common contents?

Thank you!

Answer 1

Conisder JAXB for XML Schema -> Java compilation.

XML Schema gives some possibilities for modelling iheritance:

<xs:complexType name="baseType">
    <xs:sequence>
        <xs:element name="a" type="xs:string"/>
        <xs:element name="b" type="xs:long"/>
    </xs:sequence>
</xs:complexType>
<xs:complexType name="extendedType">
    <xs:complexContent>
        <xs:extension base="baseType">
            <xs:sequence>
                <xs:element name="c" type="xs:dateTime"/>
                <xs:element name="d" type="xs:base64Binary"/>
            </xs:sequence>
        </xs:extension>
    </xs:complexContent>
</xs:complexType>

However, I don't think you can achieve exactly the Java code you're posting. You can, nevertheless get somewhat close with the inheritance plugin.