RE: Forte/CORBA inquiry - Long post

Question

Dave,
Are you using any kind of structured object in the parameters to your
CORBA-exposed method?
We have found that Forté will change the order of struct class attributes
when changes are made in the IDE (often even when seemingly unrelated).
Look at the IDL generated in your last deploy to be sure the order of
attributes is the same.
- MikeL
-----Original Message-----
Date: Thu, 3 Aug 2000 12:10:17 -0700
From: "Dave Ortman" <dortmanrcsis.com>
To: kamranaminyahoo.com
Subject: Forte/CORBA inquiry - Long post
Message-id: <3989c399.22c.0rcsis.com>
Content-Type: text/plain; charset="iso-8859-1"
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Hello,
I've been experimenting with accessing Forte through Java via CORBA. While
I have adequate experience with Forte and Java, I'm fairly new to CORBA. As
a result, I've discovered some issues which I can't seem to resolve.
I fear my explanation might be a bit lengthy, but I figure it's easier to
offer
comments when you have all the information. I apologize in advance.
I started by writing a Java application that would access a Forte service
object.
To keep things simple, I didn't use any of our existing code base. I
instead
used the code examples in tech note #10950: Forte Service Objects and
VisiBroker
Java IIOP clients. However, instead of using the VisiBroker ORB, I used the
Java 1.2 ORB. Other than that, I used the same code offered in the tech
note.
This example worked fine. I exported the IDL from Forte, ran the Sun
idltojava
tool, and compiled my Java classes.
I then tried to carry this example forward, and use some of our existing
Forte
objects. Things did not go as smoothly, and I am now left with a few
questions.
I created two new projects in my workspace - CorbaSO and CorbaManager.
In the CorbaManager I created a single class - CustomerManager. This object
has one method which retrieves a customer object based upon a CustomerID
which
is passed into the method. This project has three supplier plans which are
needed to retrieve this Customer object.
In the CorbaSO project, I created two classes - CorbaServer and TestClass.
CorbaServer has two methods: getCustomer and GetDamage. The getCustomer
method
instantiates an instance of the CustomerManager class, and uses it to
retrieve
a customer based upon the CustomerID passed into the getCustomer method,
then
returns the CustomerName (string). The GetDamage method is the same method
that's used in tech note #10950 (discussed above). I just wanted to make
sure
it still worked. I then made a Service Object from the CorbaServer class,
which
I called CorabaServerSO. This project has two supplier plans - the
CorbaManager
project discussed above, and the plan which contains the CustomerObject
(which
is returned by the CUstomerManager class).
Lastly, the test class simply contains a go() method, which I used to make
sure
the CorbaServerSO was working fine. All it does is call
CorbaServerSO.getCustomerName()
passing in a CustomerID, and writes the returning name out the logger.
The code compiles, and it works fine when I run it from within Forte
[through
TestClass.go()]. I then deployed the app and exported the IDL.
However, when looking at the IDL, I find that Forte exported 900k of IDL.
It
exported the IDL definition of every class within the supplier plan
hierarchy.
Given that I only wanted to expose my one service object, I assumed that I
would only get IDL for that one project. Instead, I got IDL for every
object
all the way down the Supplier Plan chain. So my first question is, why do I
get IDL for everything?
To make matters worse, this 900k IDL file is littered with errors - and my
IDL
compiler chokes. I edited the IDL so that it only contained definitions for
the CorbaSO project, and ran the IDLTOJAVA tool on that edited file. That
created
the JAVA files just fine, and I then compiled them into CLASS files. So far
so good.
I then wrote a Java client to call methods on my newly published
CorbaServerSO.
I found that the GetDamage() method worked fine, while the getCustomer
method
yield the following error: 'org.omg.CORBA.UNKNOWN: minor code: 1
completed:
Maybe'. This error is offered immediately after calling the getCustomer
method
on the CORBA stub.
Curious as to why one method worked, and one didn't - I looked to the code
in
the GetDamage method. The code was as follows (all undeclared variables are
input or output variables of type double):
tmp1 : i4;
tmp1 = i4(total * 0.0775 * 100.0 + 0.5);
salesTax = double(tmp1) / 100.0;
tmp1 = i4(total * 0.15 * 100.0 + 0.5);
tips15 = double(tmp1) / 100.0;
newTotalwoTips = salesTax + total + total;
As written above, the code works. I then modified the code to the following
(all parameters were unchanged):
custManager : CustomerManager= new();
tempCustomer : Customer = custManager.fetchCustomer(12345);
tmp1 : i4;
tmp1 = i4(total * 0.0775 * 100.0 + 0.5);
salesTax = double(tmp1) / 100.0;
tmp1 = i4(total * 0.15 * 100.0 + 0.5);
tips15 = double(tmp1) / 100.0;
newTotalwoTips = salesTax + total + total;
After deploying the newly modified code, I find that the GetDamage method
now
does not work. All I did was instanstiate an object, and call a method on
it.
I never did anything with the results. Yet I get the same error:
'org.omg.CORBA.UNKNOWN:
minor code: 1 completed: Maybe'.
So my two question are:
1. Why did I get IDL for every object within the Supplier Plan tree when I
was
only attempting to expose 1 Service Object.
2. Why does a method cease to work via CORBA when I interact with another
object?
Thanks in advance for any help,
-Dave Ortman

Answer 1

In a previous post, I asked:
<<Why did I get IDL for every object within the Supplier Plan tree when I
was
only attempting to expose 1 Service Object.>>
Since writing this, I have come across tech note #11427 - which mentions use
of a IIOPIgnore extended flag which you can set on objects to suppress IDL
generation. Otherwise, Forte automatically generates IDL for any object
which is marked as Distributed.
Most of our objects are distributed. I set this property on the objects
within the two projects I was working in, and the IDL for these objects was
not created. However, the rest of the objects in the Supplier Plan chain
were still translated to IDL. Am I going to have to set this property on
every object? I don't see how I could be misapplying the property - but you
never know.
<<Why does a method cease to work via CORBA when I interact with another
object?>>
Through the use of putline()'s, I've found that the error is generated
somewhere deeper within our application architecture. It may be a problem
with our code - I'm not sure. I would still be happy to hear any input on
the matter.
Thanks,
-Dave Ortman