erik,
I'm a seasoned DBA turned application developer and I'm having a hard time
letting go of SQL statements. I've centralized all database calls in a
singleton DB API.
What is the major deciding factor that makes the push to o/r mapping
necessary? Going to an o/r mapping seems labour/time intensive and at the
cost of db performance. Any advice?
Aaron
-----Original Message-----
From: erik morton [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, April 24, 2001 1:15 PM
To: [EMAIL PROTECTED]
Subject: Re: Developing an N-tier system
This is not a web development question any longer! Now you are talking about
serious OOP issues that many web developers have never had to deal with. My
best
advice to you is to read the papers on the links that I sent you. We grapple
with
this issue everyday and it never gets any easier. Our solution has been to
combine
Ambler's methods with classic GOF design patterns. And don't underestimate
the
importance of XML.
Try out the following: http://www.cetus-links.org/.
Aaron O'Hara wrote:
> 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
> >
> >
>
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> > For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST
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> > 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
>
>
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> 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
--
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
