This is disturbing to me. You have a reference
to an element, and not a reference to a type. You
wont be able to marshal the elements referenced
if you dont return elements. You also make specifying
the name of the class on the element being returned
useless, because it is not returned anyway. I dont
see why you cant extend AnElement with your Derived
type, in which case you could return elements and get
the inheritance right. I dont know enough about
schema
to understand your implementation choices.
--- Joe Fialli <Joseph.Fialli_at_Sun.COM> wrote:
> Han Ming Ong wrote:
>
> > Guys,
> >
> > Given the following schema snippets:
> >
> > <xs:element name="app">
> > <xs:complexType>
> > <xs:sequence>
> > <xs:element ref="comment-before-root"
> minOccurs="0"
> > maxOccurs="unbounded"/>
> > <xs:element ref="desc"
> maxOccurs="unbounded" />
> > </xs:sequence>
> > </xs:complexType>
> > </xs:element>
> >
> > <xs:element name="desc">
> > <xs:complexType>
> > <xs:sequence>
> > ...
> > </xs:sequence>
> > </xs:complexType>
> > </xs:element>
> >
> > I get the following API for returning desc in
> the interface AppType:
> >
> > DescType[] getDesc();
> >
> > Of course the interface DescType inherits from
> interface Desc. I
> > don't care about the rationale behind *not*
> returning Desc[] in the RI
>
> The rationale for the method signature returning the
> type of the
> element is very important
> for the general case. Future support for type
> substitution requires this
> return type.
>
> Example:
>
> Given following XML Schema:
>
> <complexType name="Base"> ....
> <complexType name="Derived"> <!-- derives by
> extension from Base -->
> <element name="anElement" type="Base"/>
>
> Any property referencing AnElement is bound to the
> following methods:
> Base getAnElement()
> void setAnElement(Base value)
>
> Here are the Java interfaces for above.
>
> public interface Base ....
> public interface Derived implements Base ..
> public interface AnElement extends Base,
> javax.xml.bind.Element ...
>
> It is important that one can handle instances of
> both Base and Derived
> for the JAXB property, AnElement. Following are
> legal instances
> of anElement in an xml document.
>
> <anElement xsi:type="Derived"> ..Content model for
> Base and
> Derived..</anElement>.
> <anElement>...Content model for Base ...
> </anElement>
>
> If the signature was constrained to the element
> interface, one would not
> be able
> to return an instance of Derived since it is not an
> instance of AnElement.
>
> It is true that your case with anonymous complex
> type definition that
> does not derive
> from anything does not allow for type substitution.
> However, there is a
> wish to not generate different looking JAXB Java
> properties to reflect the
> underlying XML as often as possible.
>
> >
> > but I would like to know if there is a way I could
> customize it in JAXB
> > generation?
>
> The current implementation is not capable of
> customizing the value returned
> by a JAXB property.
>
> In the interest of evaluating the capability that
> you need and
> what granularity it should be at, could you provide
> the rationale for
> why you need this capability.
>
> It would be possible to consider returning an
> instance of Desc for your
> example;
> however, it probably would be preferable for the
> signature to remain as is.
> Otherwise, it would introduce a JAXB customization
> that would allow
> the customizer to easily restrict the XML instance
> documents that the
> JAXB method
> signatures could handle.
>
> -Joe Fialli, Sun Microsystems
>
> >
> >
> > Naively changing the codes manually on my part
> result in
> > java.lang.ArrayStoreException eventually.
> >
> > Thanks much, Han Ming
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