Did my other suggestion not work for you?
On 7/12/06, Nick Minutello <nick.minutello_at_gmail.com> wrote:
> I can give it a try.
>
> I am just mindful of the performance impact of that.
> The major part of the payload I will be marshalling/unmarshalling will
> be the dynamic stuff.
>
> Ideally it would be nice to plug in a handler for a given class - and
> that handler would have the marshalling/unmarshalling delegated to it.
>
> -Nick
>
> On 7/11/06, Kohsuke Kawaguchi <Kohsuke.Kawaguchi_at_sun.com> wrote:
> > I wonder if you can adapt your DataObject class to DOM element by using
> > XmlJavaTypeAdapter.
> >
> > Nick Minutello wrote:
> > > Hi, thanks Dim.
> > >
> > > I will explain it as briefly and clearly as I can :-)
> > >
> > > (I have had an attempt at doing that previously, here
> > > http://forums.java.net/jive/thread.jspa?threadID=16615&tstart=0 so feel
> > > free to use that as further info)
> > >
> > > The business problem at hand is that we want people to be able to define
> > > some metadata in some storage somewhere (they would create a meta-model
> > > of concepts, their properties & relationships to each other). From this
> > > metamodel, an xml schema representation could be generated dynamically.
> > > We want people to be able to send/receive XML conforming to that xml
> > > schema to/from the server - but we don't want to have to change anything
> > > on the server. The server has a generic data object it works with - and
> > > the xml would get marshalled into and out of that.
> > >
> > > Basically, at a technical level, my problem is this:
> > > I have a bunch of classes that I want to map using JAXB - and I can do
> > > that fine.
> > >
> > > But I have 1 class where the class and the XML are going to be very very
> > > different.
> > > The class is called DataObject which is just a property bag and some
> > > Type information (The type information/metadata tells it what
> > > properties it can have (property name and property type - where one of
> > > the property types might be DataObject)
> > > But basically you can think about it as a Map of Maps.
> > >
> > > The thing is I don't want the DataObject graph to look like a map of
> > > maps when its serialised to XML.
> > > I want it to be readable. I want the xml to look like the domain
> > > concepts defined in the metamodel.
> > >
> > > So, imagine I have the following code to create a small DataObject
> > > graph:
> > >
> > > =====================
> > > // defining the metadata (in my case its stored somewhere centrally)
> > > Type personType = new Type("Person");
> > > personType.addProperty("name", Type.STRING);
> > >
> > > Type petType = new Type("Cat")
> > > petType.addProperty("weight", Type.DECIMAL);
> > > petType.addProperty("name", Type.STRING);
> > > petType.addProperty("owner", personType);
> > >
> > > // now create some instances
> > > DataObject john = new DataObject(personType, new Guid())
> > > john.setProperty("name", "John");
> > >
> > > DataObject sooty= new DataObject(petType, new Guid());
> > > sooty.setProperty("weight", 5.5);
> > > sooty.setProperty("name", "sooty");
> > > sooty.setProperty("owner", john)
> > > =====================
> > >
> > > I want sooty to look like this as XML:
> > >
> > > <pet xsi:type="Cat" name="sooty" weight="5.5" guid="32l2-k3-43j...">
> > > <owner xsi:type="Person" name="John" />
> > > </pet>
> > >
> > > And you can imagine for Fluffy, its like this:
> > > <pet xsi:type="Cat" name="fluffy" weight="15.5" guid="2433-sd9-243...">
> > > <owner xsi:type="Person" name="Billy" />
> > > </pet>
> > >
> > > So, you see the XML looks like it would come from a classes like this:
> > > class Person {
> > > String name;
> > > }
> > > class Cat {
> > > String name;
> > > Double weight;
> > > Person owner;
> > > }
> > >
> > > But these classes don't ever exist.
> > > Effectively, we want to map a bunch of different schema complexType's to
> > > one generic DataObject.
> > > We want people to be able to add a new concept to the metamodel - and
> > > the server handle it with no code change.
> > > The metadata (which would come from some storage) would tell us:
> > > A) what the xml schema would effectively look like (so clients know what
> > > to send/receive)
> > > B) how the server marshals conforming XML to/from our generic DataObject
> > > graph
> > >
> > > So, all the other static classes (like Type & Property, the
> > > ActionCommand's and their Envelopes, etc - a bunch of other stuff) I can
> > > map with JAXB no problem. However, its not clear to me if (let alone
> > > how) I can get JAXB to do the Marshalling/unmarshalling of DataObject
> > > to/from readable XML like you see above.
> > >
> > > What I *don't* want is XML that looks like this:
> > >
> > > <dataobject guid="2433-sd9-243..." doType="Cat" >
> > > <property name="name" xsi:type="xs:string" value="fluffy" />
> > > <property name="weight" xsi:type="xs:double" value="15.5" />
> > > <property name="owner" doType="Person">
> > > <dataobject guid="2433-sd9-243..." doType="Person" >
> > > <property name="name" xsi:type="xs:string" value="Billy" />
> > > </dataobject>
> > > </property>
> > > </dataobject>
> > >
> > > The XML schema in this case would tell me nothing about the domain.
> > >
> > > So, if indeed its not possible to get JAXB to do the marshalling &
> > > unmarshalling, I need to find a way I can get JAXB to delegate the
> > > marshalling/unmarshalling to me whenever it hits a DataObject.
> > >
> > > Can I do this? Does this mechanism exist?
> > > I think I can use a SAX Filter to switch unmarshalling delegation
> > > between JAXB and my own custom SAX DatObject unmarshaller.
> > > I don't see a way I can plug into JAXB's marshalling though.
> > >
> > > I thought I could be cunning and use an XmlJavaTypeAdapter to convert
> > > between DataObject and String - but of course it escapes the String
> > > contents - so marshalling my DataObject into an xml string wasn't the
> > > droid I was looking for...
> >
> >
> > --
> > Kohsuke Kawaguchi
> > Sun Microsystems kohsuke.kawaguchi_at_sun.com
> >
> >
> >
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe_at_jaxb.dev.java.net
> For additional commands, e-mail: users-help_at_jaxb.dev.java.net
>
>