That is similiar to what I started. I made a
findByPrimaryKey(UserPK pk) that returns a UserBean
object containing the data (also insert, update, and
delete). So on the user end you only deal with the
data and don't have to worry about the persistence
method. What I started probably another layer as an
interface. You can let me know what you think once
you look at it.
Do you recommend the "Core J2EE patterns" book?
David
--- Ted Husted <[EMAIL PROTECTED]> wrote:
> I'm thinking of a Data Access Object model, where
> either the EJB or JDBC
> call would be inside a wrapper so the caller would
> have no idea where
> the data is coming from. So the method signature for
> a select on a
> primary key might look like
>
> public static final RowSet accountSelect(int
> key)
>
> This returns a RowSet as a "value object", but
> RowSets can be generated
> on the fly, so the data could be retrieved from
> anyplace. If all the
> data accesses are wrapped up this way, you can
> change form JDBC or EJB
> or whatever, without the rest of the application
> being the wiser.
>
> In the Core J2EE patterns book, there is even talk
> of DAO factories, the
> idea being you might a DAO Oracle implementation or
> a DAO MySQL
> implementation, and the application could be
> configured to call one one
> day and the other the next.
>
> I'm now using a Helper object between the Action and
> the DAO. The Action
> selects the Helper, and passes it any necessary
> parameters, the Helper
> selects the DAO, and catches the RowSet. The Helper
> is then inserted
> into the context for access by the presentation
> layer. The Helper gives
> you a place to put special output methods for the
> presentation layer (or
> report layer, for that matter). Neither the Helper
> nor the DAO are
> linked to HTTP or a Web application.
>
>
> David Winterfeldt wrote:
> >
> > What DBMS design patterns were you thinking of? I
> was
> > thinking that it would be nice if you could
> migrate
> > from JDBC to EJB without having to change
anything.
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