RE: Additional interfaces for proxy objects?

Hi,

On 1 Dec 2004 at 13:04, Aidan Slingsby wrote:

> > Is it possible for proxy classes to implement more than one 
> > interface?  I was hoping that OPP would would automatically 
> > give the proxy classes all the interfaces listed in the Impl 
> > class, but they are only given the one Ozone interface 
> > (inherited from OzoneRemote).
> 
> I should perhaps give a few more details of what I want.  I am slightly hazy
> about exactly how all this works - sorry.
> 
> I used to have an interface called Line (which extended OzoneRemote) and a
> class called LineImpl (extended from OzoneObject).  Proxy classes were
> generated in the usual way.
> 
> The problem is that there are cases when I wish to temporarily create a
> LineImpl) i.e. outside the database to be used in the short term.  I'd do
> this by new NodeImpl().  As long as I wasn't passing between client and
> server, this was fine.  And I didn't, because it was only short-lived.  This
> was my workaround.
> 
> There is now a situation where I wish to pass the temporary Line between
> client and server, and of course I get a "not (yet) in database" error.
> 

Transferring a regular java object (serializable) between client an 
server is possible in 
standard way: as a parameter of an ozone object method and returning 
as argument 
of a return statement. This object is serialized and transferred in 
both directions.


> My solution was to have two interfaces.  One called Line (standard Java) and
> one called LineDB (which extends OzoneRemote), both with the same methods
> defined.  Then have a class LineGeometry (a standard Serialisable Java
> object) and LineDBImpl (an object object).  LineDBImpl is a wrapper object,
> which has a protected LineGeometry variable and all the methods in the
> interface passed through to LineGeometry.  Since LineGeometry implements
> Line and LineDBImpl implements Line and LineDB, they can both be treated as
> Line.  The idea is that a Line could be a LineGeometry, a LineDBImpl (which
> wraps around LineGeometry) or a proxy.  I was hoping that the proxy object
> could also implement Line and LineDB, so it can be treated as Line.
> 

You can only reach an ozone object by a proxy. It is impossible to 
work with a regular 
java object this way.

Cheers,
Wieslaw



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