i would appreciate comments on this question too. my two cents:
* how complex is your data and object models - e.g., if you object model
uses inheritance your o/r tool should support this to map nice to db.
* how much can you afford - app servers supporting ejb are expensive, as are
some o/r tools...are you willing to go with open source, e.g., castor
* skill set/timeframe - developers need to learn o/r tool
* how robust a solution do yo need? do you need to support distributed
transaction (two phase commit)
those are what i can think of top of my head.
tinou
----- Original Message -----
From: "Aaron O'Hara" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, April 24, 2001 3:32 PM
Subject: Re: [JSP-INTEREST] Developing an N-tier system
> What major considerations are there in choosing a solution to implement
> object to rdb mapping?
>
> Aaron
>
> -----Original Message-----
> From: erik morton [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, April 24, 2001 12:21 PM
> To: [EMAIL PROTECTED]
> Subject: Re: Developing an N-tier system
>
>
> The biggest advantage that I can see for using JSPs instead of Servlets
for
> the
> "workflow" layer is Rapid App Development - that's it. As a previous
reader
> pointed
> out, Servlets are true objects where JSPs are really just a temporary
> concept that
> are translated into actual servlets at deploy/runtime. On the other hand,
if
> you
> place ALL of your business logic inside beans than I see little need for
> servlets.
> But you must put ALL of the logic in the beans - I don't want to see a
> single IF
> statement in those JSP pages and don't even think about accessing the
> database :-).
> I said it before and I will say it again: spend time working on your
> persistence
> model. The truly robust systems that I have seen have persistence models
> where you
> can change the data model all you want and you never recompile your code.
As
> a rule
> of thumb, we never embed SQL in the middle tier.
>
> You can call me Captain Obvious if you want.
>
> some links:
> http://www.ambysoft.com/
> http://www.castor.org/
>
>
> Aaron O'Hara wrote:
>
> > All,
> >
> > I'm designing an N-tier application and would like some feedback,
> comments,
> > notes from the field. I have tried to layer my design as follows:
> >
> > JSP/HTML - presentation layer
> > Non-Gui JSP - workflow layer
> > Scope Beans (page, request, session, application) - business logic
> > Psuedo Entity Beans - persistence layer
> > DB API - database services
> >
> > In the presentation layer, I either present information to the user or
> > receive form information. All the form submissions go to the workflow
> layer
> > which calls the necessary business logic beans to determine what should
> > happen next. The business logic beans retreive or save data using the
> > psuedo entity beans. (I say psuedo because this in not a EJB entity
bean,
> > but an object that maps to a corresponding table in a database). All
the
> > entity beans perform their database operations via a singleton class,
the
> DB
> > API.
> >
> > I'm looking for a critique or comments from people about the design I've
> > adopted and implemented.
> >
> > Aaron
> >
> >
>
===========================================================================
> > To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff
> JSP-INTEREST".
> > For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST
> DIGEST".
> > Some relevant FAQs on JSP/Servlets can be found at:
> >
> > http://java.sun.com/products/jsp/faq.html
> > http://www.esperanto.org.nz/jsp/jspfaq.html
> > http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
> > http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
>
> --
> Erik I Morton
> Software Developer
> ------------------
> CommerceHub
> http://www.commercehub.com
> 518-886-0704
> 21 Corporate Drive
> Clifton Park, NY 12065
>
>
===========================================================================
> To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff
> JSP-INTEREST".
> For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST
> DIGEST".
> Some relevant FAQs on JSP/Servlets can be found at:
>
> http://java.sun.com/products/jsp/faq.html
> http://www.esperanto.org.nz/jsp/jspfaq.html
> http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
> http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
>
>
===========================================================================
> To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff
JSP-INTEREST".
> For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST
DIGEST".
> Some relevant FAQs on JSP/Servlets can be found at:
>
> http://java.sun.com/products/jsp/faq.html
> http://www.esperanto.org.nz/jsp/jspfaq.html
> http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
> http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
>
===========================================================================
To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST".
For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST".
Some relevant FAQs on JSP/Servlets can be found at:
http://java.sun.com/products/jsp/faq.html
http://www.esperanto.org.nz/jsp/jspfaq.html
http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
