This appears to be a missing jar from your dll I've not looked at IKVM but I presume it does some magic to work out what classes need to be include - magic which probably fails if the classes are referenced indirectly via reflection or some other means (eg if there is a pluggable service architecture dynamically picking which implementation to use. You may be able to get round this by explicitly specifying the jars/classes that you need.

You may also run into further issues when it tries to compile your rules as they may reference other jars and classes (if it is able to compile them at all!

Thomas

-----Original Message-----
From: rules-users-bounces@lists.jboss.org [mailto:rules-users-
bounces@lists.jboss.org] On Behalf Of FrankVhh
Sent: 02 February 2011 08:41
To: rules-users@lists.jboss.org
Subject: Re: [rules-users] Drools Java and .Net


Hi all,

Thanks for your inputs. As you suggested, this week I tried to use IKVM
to
make Drools and .NET work together.

Converting the Java implementation of drools to dll, importing dll into
.NET
and calling the java functions isn't that hard, once you are a little
bit
familiar with ikvm. No syntax errors in Visual Studio when I do this.

However, there seems to be going something wrong on execution. It
appears to
me that the execution environment does not recognize the "drools-
language".

The execution crashes on the first call of Drools code
(knowledgebuilderfactory.new KnowledgeBuilder()) with the errors:
    - IllegalArgumentException : Unable to instantiate service for
Class
'org.drools.builder.KnowledgeBuilderFactoryService"
    - ClassNotFoundException:
org.drools.builder.impl.KnowledgeBuilderFactoryServiceImpl

This means there are some dependancies missing, right? But should I be
looking to add some jars to the IKVM-JVM? Or is this definitely a
problem of
wrong jar to dll conversion?

Corneil, could you tell me whether you ran into dependancy problems as
well?

fyi I also tried to import the drools library as dll into .NET and then
rewrite the entire wrapping code in .NET. This didn't return any syntax
errors either, but got stuck in execution as well. (With same errors).

Regards,
Frank


Corneil du Plessis wrote:

We have successfully used IKVM to create a dlls for our Drools
application.

The performance was a bit slower on IKVM/.Net as in Sun Java 5.
We dynamically load a large number of rules and found the largest

impact

is to the 'load time'

The performance impact was not such that it would make a network call
viable; especially with 1000s of clients.

Apart from the performance impact the behaviour is exactly the same.

On 25/01/2011 17:04, FrankVhh wrote:

Hi all,

Suppose that you have a rule engine that needs to be embedded on the
machine
and that there is no way to call the rules as a service from a
centralized
server, what approach would one have to choose to make Drools and

.NET

work?

The rulke engine will have to be cached to improve performance, so

that

part, until there is an up-to-date version of Drools.NET, has to be

in

Java
anyway. Then you expose your JAVA code as a (local) service and let

.NET

call it? Or am I seeing things wrong here?

I must stipulate that I am not an expert in .NET at all, and I know

only

barely enough Java to get Drools working :-).

Thanks for your help.

Kind regards,
Frank


salaboy wrote:

Yes, and if you want to use the rule engine from .NET you can use

the

Drools
Server that expose the Drools Runtime in REST and SOAP interfaces

:)

Greetings.

2011/1/19 Michael Anstis<michael.anstis@gmail.com>

Hi,

I believe the .NET implementation of Drools is somewhat out dated.

However Drools ticks all your other requirements.

With kind regards,

Mike

2011/1/19 Gorantla, Bhaskar (GE Capital)<bhaskar.gorantla@ge.com>

We are looking for a rules engine that has the following
characteristics.



1.       Supports both Java and .net

2.       Provides a business user friendly UI for

creating/editing

rules

3.       Supports versioning

4.       The rues in the rules repository are accessible to both

Java

and
.net applications – Nice to have



Do you know whether Drools supports all the above?



Thanks



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