Anyone successfully managed using a CachedRowSet of some kind?
The way I understand it, it would be the vehicle of choice to pass data
between the EJB and the client...
CachedRowSet crs = new CachedRowSet();
crs.setDataSourceName("somedatasource");
crs.setCommand("Select * from sometable");
crs.execute();
return crs;
I'd like your thoughts/experiences with that.
Alternatively, if anyone of you uses Borland's DataExpress components,
are TableDataSet serializable and
transportable from EJB to client ? (This could actually prove more
useful to me, albeit less "portable")
Cheers,
Daniel
-----Message d'origine-----
De : Guy Rouillier [mailto:[EMAIL PROTECTED]]
Envoyé : 24 avril, 2001 11:07
À : [EMAIL PROTECTED]
Objet : Re: [JBoss-user] Jboss-bug or misunderstanding ? (Loosing
reference to JBoss object)
>From reading your text below, it sounds like you are returning a
ResultSet
object to the client and letting the client next() through it. If I'm
interpreting that properly, you should not do this. Only the EJB on
JBoss
should talk to the database. All within a single method, obtain the
connection, execute the query, get the ResultSet, loop through the
result
set and do something with it, close the result set, statement and
connection, and then return. As to what to do with the ResultSet, you
can
materialize it as a set of Java objects or (as we prefer to do) and XML
string.
----- Original Message -----
From: "René Rolander Nygaard" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, April 24, 2001 3:57 AM
Subject: RE: [JBoss-user] Jboss-bug or misunderstanding ? (Loosing
reference
to JBoss object)
> René Rolander Nygaard wrote:
>
> > We are getting pretty desperate regarding this question, so I
> have to ask
> > again!
>
> Dude, try rephrasing the question. The following paragraph makes
> no sense.
Sorry - i will try once more.
> > Through our speed-testing we are seeing more strange behaviors.
> > It seems as JBoss looses the reference to an object if you
speed-clicks.
> > This can only mean that the problems occurs because the same session
is
> > trying to access the same object more than once.
>
> What is "speed-clicks"? What does "looses the reference to an
> object" mean?
This was actually from my originally mail where i wrote that we
"speed-tested" the system by clicking on a menu-item, which caused a
reload
in another frame on the screen.
The "looses a reference" is that we have a reference from our jsp page
through a bean to a JBoss stateless session bean.
We select data from a resultset, and after we cycled through all items,
we
try to close the connection, the statement etc. but these objects are
null!
We still have a reference to the JBoss stateless session bean, but we
fear
that it is either a different stateless bean than we started with,
OR it has been re-initialized.
>
>
> > If you from a jsp page force a reload before the last page-load was
> > finished, it seems that the reference from the jsp page through
> to the JBoss
> > stateless bean is lost!
> >
> > Can we expect that in one work-cycle we get a reference to at
different
> > JBoss stateless bean, and if this is the case - we cannot clean
> up after us
> > self.
> >
> > The scenario again:
> > A jsp page gets a reference to a stateless session bean
> > The jsp page starts traverse a resultset
> > <Here we reload the page!>
> > The disconnect functions all fail because the objects == null!
> > Sorry about this, but i cannot see this any other way than a
> JBoss bug...
>
> Do you realise that the same JSP instance can service multiple
requests
> simultaneously. If you are storing things in instance variables then
> the second request will overwrite them before the first completes.
This
> is basic JSP/servlet stuff.
Hmm. Yes - but here we make a <USEBEAN> on a page object (and we also
tried
making the bean session).
Then we cycle through all data
finally we call the Close all function.
When we are running in the same jsp page, can we expect that the data
contained in one jsp page is overridden if the user click's to quickly ?
I hope this is not the case.
Thnx for the response dude! ;-)
- René Rolander Nygaard
>
> Toby.
>
>
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