Design Patterns discussion

[Eduardo Franco <eduardo.franco AT pulso.com.br>]

I don't think the Strategy is the best pattern for your problem. I don't
even know much about the context your are developing the system, but
AFAICS the best suitable pattern is the "Abstract Factory".

[..]

"Provide an interface for creating families of related or dependent
objects without specifying their concrete classes."

[..]

This pattern let you vary families of product objects when the
"Strategy" pattern let you vary an algorithm which I don't think is your
real problem.

Regards,

--
Eduardo Franco

Zhai wrote:
> In a software system, we meet the following
> requirements:
>   a client program, when running, have to set or get a
> parameter, named paraValue.
> But the parameter paraValue could be stored in a file
> named filePara, or in a relation
> database, such as Oracle. Now we design an abstract
> class "CParaAccess", with two
> public virtual functions setPara() and getPara() to
> set and get the parameter.
> There are two subclasses "CFileParaAccess" and
> "CDatabaseParaAccess" inherited
>  from "CParaAccess", all implement setPara() and
> getPara(). However in 
>  "CFileParaAccess" and "CDatabaseParaAccess", the
> principle to implement
>  setPara() and getPara() is different. 
>    In the design we can understand the client had two
> strategies to set/get the 
>  parameter, i.e. from a file or a database. so can we
> think our design cohere 
>  with the Strategy design pattern? If not, which
> pattern could we use to improve
>  the design?
>  thx.