Confusion with BusinessObject implementations 2004-08-19 - By Robert Taylor
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So it seems like you would subscribe to METHOD 2 implementation and that the
BusinessObject would use (have as a data member) the
appropriate DAO to manage (persist and access) its state.
robert
> -- --Original Message-- --
> From: An interest list for Sun Java Center J2EE Pattern Catalog
> [mailto:J2EEPATTERNS-INTEREST@(protected)]On Behalf Of Keswani, Mohit
> Sent: Thursday, August 19, 2004 12:04 AM
> To: J2EEPATTERNS-INTEREST@(protected)
> Subject: Re: Confusion with BusinessObject implementations
>
>
> Hi Robert,
>
> "BusinessObjects encapsulate and manage business data, behavior and
> persistence"
> The statement implies that persistence is achieved not in Business Layer but
> by using DAO layer.
> The word which is tricky here is "encapsulate and manage". So business
> objects contain the logic to maintain data, behaviour and persistance
> through DAO.
>
> I hope this clears your doubt.
>
> Regards
> Mohit Keswani
>
> -- --Original Message-- --
> From: Robert Taylor [mailto:rtaylor@(protected)]
> Sent: Thursday, August 19, 2004 5:55 AM
> To: J2EEPATTERNS-INTEREST@(protected)
> Subject: Confusion with BusinessObject implementations
>
> Greetings,
>
> I've been reading Core J2EE Patterns, Second Edition and for the most part
> it has really been helpful in explaining the architectural entities of the
> enterprise.
>
> However, after reading the section on the business tier and having various
> discussions with other architects I'm confused about the following passage
> on page 375 in the BusinessObject section (chapter 7).
>
> "BusinessObjects encapsulate and manage business data, behavior and
> persistence."
>
> This seems to imply that the BusinessObject should contain methods like
> create(), update(), delete(), and various finder methods for managing its
> own persistence and data access along.
>
> This, however, does not seem to be the concensus when implementing
> BusinessObjects.
>
> Most architects manage persistence extrinsically to the BusinessObject
> itself.
> That is, they use the appropriate DataAccessObject to persist and access
> BusinessObjects; usually within some type of ApplicationService or
> ServiceFacade.
>
> For example:
>
> // Creating a new account METHOD 1
> Account account = // populate account BusinessObject AccountDAO accountDAO =
> // get an instance of AccountDAO accountDAO.create(account);
>
>
> as opposed to...
>
> // Creating a new account METHOD 2
> Account account = // populate account BusinessObject account.create(); //
> create a new account delegating persistence to AccountDAO
>
>
>
> It seems like METHOD 2 is more OO but requires the BusinessObject to become
> a facade to the DAO, where as METHOD 1 seems more procedural but has a
> clearer architectural separation of responsibility.
>
>
> Can anyone give me some pros and cons on the above two approaches?
> Is one better than the other?
>
> robert
>
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