Thank for the tips. : )

I have added the required mvel14-1.2.8.jar in my classpath. However, I still encounter the same error.

Could it be a class loader issue or JRE version?

I tried to trace the class loader. Drools is used in my application (running in netbeans). My application is using java.net.FactoryURLClassLoader. On plain netbeans project (before the error occurs), the class loader is sun.misc.Launcher$AppClassLoader. My netbeans is using JRE v 1.6.0

The error occurs when PackageBuilder is initialised.

Package Builder builder = new PackageBuilder();

Also, for the Drools Eclipse plugin (on a seperate occassion), when i import some codes, it prompt me that Drools project is not a Java 5.0 project.

Chong Minsk Goh wrote:
> Hi,
>
> I am trying to run Drools on Netbeans. I have added the jars from
> Drools 4.0.2.
>
> However, I encountered an error
>
> org.doxa.rules.RulesManager - org.drools.RuntimeDroolsException:
> Unable to load dialect
> 'org.drools.rule.builder.dialect.mvel.MVELDialectConfiguration:mvel'
MVEL is a required jar, not an optional one, put it on your classpath
and hopefully this should work for you.
>
> I did not use any MVEL dialects in my rules definition. Here is my rule:
> *
>
> rule
>
> * "Out of Range" *when* m : Message( message == "checkRange" , status
> == 1 )
>
> Range(myMin : myMin, myMax : myMax, myValue : myValue)
>
> Range(myValue < myMin || myValue > myMax)
>
> *then* m.setMessage("");
>
> m.setStatus (0);
>
> *end*
>
> Has anyone attempted using Netbeans with Drools and faced this problem?
>
> Best regards
> Eric