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Questions tagged [drools]

Drools is a business-rule management system (BRMS) with a forward-chaining-inference-based rules engine, more correctly known as a production rule system, using an enhanced implementation of the Rete algorithm.

https://www.drools.org/

Drools is a Business Rules Management System (BRMS) solution. It provides a core Business Rules Engine (BRE), a web authoring and rules management application (Drools Workbench), full runtime support for Decision Model and Notation (DMN) models at Conformance level 3 and an Eclipse IDE plugin for core development.

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What is Mvel dialect in Drools?

I am new to Drools. I am creating a rule but I get a compile time error "field is not visible'. I've tried to check with Jboss examples, where they use dialect "mvel". It compiled. I didn't understand about dialect. So what is dialect=mvel?
tech2504
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Drools get facts from database at runtime

I need a little help with Drools eval and variable assigning. rule "check that no previously submitted requests exist" when $user : UserFormField( name == 'employeeId', value != null ) $repository : Repository( ) $activeRequests :…
ATMTA
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Retrieving facts of a specific type from working memory

Instead of retrieving all facts i need to retrieve specific type of facts from working memory. i learnt that i can retrieve all the facts from working memory as…
user1668653
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How to deploy a rules kjar to S3 bucket from within the kie workbench?

I am trying to use a S3 bucket as a remote maven repository via which to distribute the rules jar, created with the kie workbench UI, to where they are needed. If i package the rules with maven from my IDE, i can successfully upload the jar to s3…
Claude Sylvanshine
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Configuring drools and maven and writing hello world application using them

I want to learn drools and maven can any one help me with the links for configuring drools and maven and writing a basic hello world example using them. Thanks in advance
Anupam Gupta
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Implementing methods having raw types in Scala

I have a problem in using Drools Planner (written in Java) in Scala. One of interfaces in Drools planner is declared as: public interface Score extends Comparable However another interface uses 'Score' as a raw type: public…
iirekm
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Drools XStream in a spring service

I'm starting to work with drools , I wanted to use it in spring-boot service, but even for a simple example I 've got a no such method error on Xstream. What did I miss? Caused by: java.lang.NoSuchMethodError:…
Goofyrocks
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How to use a Spring Service in Drools rules?

I'm working with drools engine in the construction of an alert system. we need to execute a method of a @Service instantiated by Spring Framework on the actions of the rule (RHS), when the conditions are met. What would be the way to get the…
Hector Gomez
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Drools performance for decision tables

I have a potential performance/memory bottleneck when I try to calculate insurance premium using Drools engine. I use Drools in my project to separate business logic from java code and I decided to use it for premium calculation too. Am I using…
przemek hertel
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Possible causes for "StreamCorruptedException: invalid stream header"

I (try to) use drools to process my pricing rules. But when I try to execute the rules the following exception is thrown: java.lang.RuntimeException: KnowledgeAgent exception while trying to deserialize KnowledgeDefinitionsPackage at…
Arne Deutsch
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Getting java.lang.NullPointerException while calling activate method on TaskClient

Getting null pointer exception while starting calling the activate method on client object.Here is my code. @RequestMapping(value="/loanreq",method=RequestMethod.GET) public String loanRequest(HttpServletRequest req,HttpSession session) throws…
Srinath Murugula
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how to load drl file from file system in drools 6.3.0

Hi I am trying to load drl file from file system in drools 6.3.0. I got the code from drools project. Code that is used to load drl file is as follows. package org.drools.examples.banking; import org.kie.internal.KnowledgeBase; import…
chandra
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drools drl how to do not conditions

I am trying to write a rule in drools drl language where I am want to do something like !(A && B) but it doesnt seem to like the ! operator or the word not. I am struggling to find good documentation on drools Please see sample code below: rule…
mh377
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Unable to run "Hello World" Drools example in Eclipse: runtime exception org.drools.RuntimeDroolsException: Unable to load dialect

I just installed the Drools plug-in in Eclipse (version 3.5.2), and I am trying to run the "Hello World" example that comes with the plug-in. When I run the code, I am getting runtime error with the following stack…
user396377
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Using drools expert with dynamic decision tables

Here's what I had like to do. I had like to put "rules" in a database table. This is sort of like the drools xls decision table format except that all the rules will be rows in a table. This way I can modify the rules easily . I need to put this in…
Zenil
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