hello all,
since it came up, this is an issue that i and our
other programmer have been wrestling with for a while,
because like everyone else we feel the pressure to use
the cool new stuff..and we wonder if the transactional
and distributed advantages will help us out.
here is my problem. call me dense, but i just don't
see or mapping being as flexible as i need it to be.
in all the books the examples tell you that you map
your object to the table that holds its data. sounds
fine in theory, but we have some very complex objects,
and we have a complex relational model, the reason for
which is to store our data efficiently, not only for
this application, but also for others. so we have
objects that need to get their data from different
tables, even different databases. these objects
contain collections, single entities, indexes into
other objects, etc., all of which must be persisted in
the db. we have solved the problem by writing our own
dblayer, employing reflection and stashing all our
queries (as well as caching them and the connections)
in a static lookup object. this gives us a level of
control over the data that i cannot see us getting
from any OR tool, no matter how smart (and remember,
the smarter something is, the slower).
as to transactional support, we use jts or the db
transaction services. no problems..
as to servlets, we use exactly one per application,
mereley to take the requests and to control
everything--everything else is plain old java classes.
it is blazingly fast. i cannot believe that looking
up objects through jndi is going to be as quick as
looking up my classes in a hashmap.
if i want distribution, i simply break my app into
multiple apps, run them on separate machines, and use
the same object model--thats one benefit of oo, right?
i hope someone has the time to refute me completely,
because, like kevin, i really do want to understand
what ejb will give me that i cannot live without. my
greatest concern, as i mentioned above, is OR mapping.
i have been a dba and a programmer, and i find it
really difficult to believe that some tool is going to
produce more efficient and more flexible access to my
data than i can, given that i currently have full
control from table to view to sp to accessor methods
on objects..
bradley mclain
--usmoving.com
--- "Duffey, Kevin" <[EMAIL PROTECTED]> wrote:
> Hi Mike (and all),
>
> Actually, while Struts is pretty kewl, there are
> some things that I wish
> were modified that won't be for reasons of the
> general population interest
> instead of my own. Because of this, while I will
> continue to use Struts at
> work, my own projects will use my own solution,
> similar to Struts but not
> near as robust in some ways, but a bit better on
> performance. The one thing
> I really dislike, but I agree with based on what
> Craig has told me, is that
> every single form submission causes the
> auto-population feature to get
> called (reflection). I only want it to be called if
> an update occurs. If the
> user hits cancel to go back, or what not..I don't
> much care what they just
> entered. Only when doing searches or updates/entry
> on forms should it be
> called. For that reason I am doing my own reflection
> population routine that
> does use nested objects. But overall Struts kicks
> ass in what it offers for
> a free package.
>
> Did I compare Struts to EJB? I didn't mean to in
> terms of performance.
>
> > -----Original Message-----
> > From: Mike Cannon-Brookes
> [mailto:[EMAIL PROTECTED]]
> > Sent: Monday, October 09, 2000 4:12 PM
> > To: Orion-Interest
> > Subject: RE: EJB vs Servlets
> >
> >
> > I have to laugh when someone compares Struts to
> EJBs for performance.
> >
> > I've used both and I'd have to say Kevin that if
> you factored
> > your code away
> > from Struts and used EJBs instead you'd have a
> very VERY
> > minimal performance
> > impact (if any noticable at all).
> >
> > And looking up EJBs is really very simple two
> lines of code
> > (or one little
> > JSP tag <ejb>).
> >
> > Although if you wanted to attach a Swing client to
> Struts...
> > you'd have much
> > greater problem I fear? ;)
> >
> > Mike
> >
> > PS Struts does have some cool points, I wish
> they'd break out
> > the i18n stuff
> > into another library, it doesn't seem to fit
> there.
> >
> > > -----Original Message-----
> > > From: [EMAIL PROTECTED]
> > > [mailto:[EMAIL PROTECTED]]On
> Behalf Of
> > Duffey, Kevin
> > > Sent: Tuesday, October 10, 2000 5:01 AM
> > > To: Orion-Interest
> > > Subject: RE: EJB vs Servlets
> > >
> > >
> > > Actually, I know all about it. I have read up on
> it in
> > those books and
> > > others. Infact, we have already separated our
> code into
> > those tiers but it
> > > all runs in the servlet engine. This is what I
> am talking about.
> > > I am using
> > > the Struts framework to allow all forms
> submitted to a
> > single controller
> > > servlet, which then calls upong action classes.
> Those
> > action classes then
> > > figure out what "session" class to call upon.
> These
> > "session" classes are
> > > our logic (ejb) code, but its not in the EJB
> container..it
> > runs in our
> > > servlet engine. It is separated, just not from
> the servlet
> > engine itself.
> > > However, by compexity of building EJBs, I think
> I mean what
> > goes into it.
> > > Instead of a single class, we would have 2 (or
> is it 3)
> > interfaces and an
> > > implementation class. To access it, its not as
> simple as a
> > class/reference
> > > variable to an object in the servlet engine, you
> have to do
> > a lookup,
> > > etc..its a bit more code. Sure..its not terribly
> complex,
> > but compared to
> > > doing it the way we are now, there is quite a
> bit more work
> > involved than
> > > what we are doing now. Also, actually testing
> and learning
> > how exactly it
> > > works is a process that will take a little time.
> All of these
> > > things add up.
> > > What I am wondering is..is it really worth it if
> supposedly
> > EJB doesn't
> > > offer much in the way of performance..it just
> separates the
> > logic into a
> > > separate "tier" of servers. Our code is already
> separated
> > long those tiers
> > > now..and it will probably be easier for us to
> move to EJB
> > than those that
> > > have logic in their servlets.
> > >
> > >
> > > > -----Original Message-----
> > > > From: Russ White
> [mailto:[EMAIL PROTECTED]]
> > > > Sent: Monday, October 09, 2000 11:32 AM
> > > > To: Orion-Interest
> > > > Subject: RE: EJB vs Servlets
> > > >
> > > >
> > > > You should read up on J2EE so you can
> understand what
> > separation of
> > > > data/logic/presentation is all about. I would
> recommend any
> > > > of the O'Reilly
> > > > books on the subject(s). Also Development of
> EJBs is very
> > > > simple. Especially
> > > > with a good IDE like VA, Forte, or JBuilder.
> Orion even comes
> > > > with a simple tool
> > > > for creating very useful EntityBeans from a
> GUI.
> > > >
> > > > > -----Original Message-----
> > > > > From: [EMAIL PROTECTED]
> > > > >
> [mailto:[EMAIL PROTECTED]]On
> Behalf Of
> > > > Duffey, Kevin
> > > > > Sent: Monday, October 09, 2000 1:22 PM
> > > > > To: Orion-Interest
> > > > > Subject: EJB vs Servlets
> > > > >
> > > > >
> > > > > Hey all,
> > > > >
> > > > > I know this is a little off-topic, but
> seeing as how Orion
> > > > is about the only
> > > > > fully compliant EJB server, I figured this
> would be a
> > > > better place to ask.
> > > > >
> > > > > Lately I have talked to a number of people
> that have been
> > > > moving towards EJB
> > > > > and pulled back because they have found it
> to be more
> > > > tedious to develop, as
> > > > > well as the end result was slower than just
> using Servlets.
> > > > >
> > > > > I ask this because it appears to me that the
> servlet engine
> > > > (at least with
> > > > > 2.2) being able to be failed over,
> load-balanced, etc,
> > > > seems to be quite as
> > > > > capable for scalability and fault-tolerance
> as the ejb
>
=== message truncated ===
__________________________________________________
Do You Yahoo!?
Get Yahoo! Mail - Free email you can access from anywhere!
http://mail.yahoo.com/
