[saga-rg] Is there Factory in Java Binding?

[Andre Merzky]

Hi Hidemote, Graeme, 

please excuse my ignorance - as said before, I am Java
agnostic, and my question might be off target...

Hidemote mentioned the use of the factory pattern at GGF
already, and other people I know which do Java issued
similar statements.

How does that actually compare to other languages?  E.g. in
C/C++, you can usually link your code against a specific
_API_ in a shared library - as long as a library implements
the same API, there is no need to recompile (just exchange
library).

Also, in C/C++ it is possible to implement an API with
plugins: so you create a thin API layer, which forwards to
dunamically loaded plugins, which can then provide different
implementations of the API calls.

The latter way is what we actually do in our C++
implementation (plugins are called adaptors though).

The difference I see is actually that in both cases, the
fact that the API is implemented by different vendors is
completely hidden on API level, w/o the need for any
additional patterns like factories.

So, is there a difference between these approaches?  And if
not: what is the advantage of the factory approach?

Thanks, 

  Andre.


Quoting [Hidemoto Nakada] (May 17 2006):
> 
> All,
> 
> I have a question on the Java Binding.
> Does the current Java binding include explicit factory notion?
> 
> Factory mechanism is important to
> - reuse a source code with several implementation of the API
>    without modification of the code.
> - leverage several implementation simultaneously from one
>   client code.
> 
> One good example of factory design can be found in the Dom parser
> definition; org.w3c.dom.DomImplementation.
> When you create a Dom document
> 
> - get a DomImplementation from org.w3c.dom.bootstrap.DomImplementationRegistory
> - then create a Document object using DomImplementation.
> 
> This mechanism might be too complicated for SAGA, but
> I think some flavor of this is required.
> 
> -hidemoto
> 
> 
> 
> 



-- 
"So much time, so little to do..."  -- Garfield