[rules-users] Problem with Banking Tutorial

[Stefan Schuster]

For the sake of  completeness, here is also the RuleRunner class used in
this example:

package org.drools.tutorials.banking;

import java.util.Collection;

import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.definition.KnowledgePackage;
import org.drools.io.ResourceFactory;
import org.drools.runtime.StatefulKnowledgeSession;

public class RuleRunner {

    public RuleRunner() {
    }

    public void runRules(String[] rules,
                         Object[] facts) {

        KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
        KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder();

        for ( int i = 0; i < rules.length; i++ ) {
            String ruleFile = rules[i];
            System.out.println( "Loading file: " + ruleFile );
            kbuilder.add( ResourceFactory.newClassPathResource( ruleFile,

RuleRunner.class ),
                                  ResourceType.DRL );
        }

        Collection<KnowledgePackage> pkgs = kbuilder.getKnowledgePackages();
        kbase.addKnowledgePackages( pkgs );
        StatefulKnowledgeSession ksession =
kbase.newStatefulKnowledgeSession();

        for ( int i = 0; i < facts.length; i++ ) {
            Object fact = facts[i];
            System.out.println( "Inserting fact: " + fact );
            ksession.insert( fact );
        }

        ksession.fireAllRules();
    }
}


2013/4/18 Stefan Schuster <stefan.m.schuster at gmail.com>

> Hello,
>
> I have a problem with the banking tutorial number 3, which is part of the
> examples of drools expert.
> It simply adds some Numbers as facts, and retracts them in an increasing
> order.
>
> It is very short, therefore I post the whole Code:
>
>
> BankingExample3.java
> _________________________________________________
> package org.drools.tutorials.banking;
>
> public class BankingExample3 {
>     public static void main(String[] args) {
>         Number[] numbers = new Number[] {wrap(3), wrap(1), wrap(4),
> wrap(1), wrap(5)};
>         new RuleRunner().runRules( new String[] { "Example3.drl" },
>                                    numbers );
>     }
>
>     private static Integer wrap(int i) {
>         return new Integer(i);
>     }
> }
> _________________________________________________
>
>
>
> Example3.drl:
> _________________________________________________
> package org.drools.tutorials.banking
>
> rule "Rule 01"
>     when
>         $number : Number()
>         not Number( intValue < $number.intValue )
>     then
>         System.out.println("Number found with value: " +
> $number.intValue() );
>         retract( $number );
> end
> _________________________________________________
>
>
> Output:
> _________________________________________________
> Loading file: Example3.drl
> Inserting fact: 3
> Inserting fact: 1
> Inserting fact: 4
> Inserting fact: 1
> Inserting fact: 5
> Number found with value: 1
> Number found with value: 1
> Number found with value: 3
> Number found with value: 4
> Number found with value: 5
> _________________________________________________
>
>
> that seams absolute logically to me.
> But now I alter the Numbers in the Java-Part:
>  Number[] numbers = new Number[] {wrap(3), wrap(1), wrap(2)};
>
> and the output destroys everything I thought I understood:
> Loading file: Example3.drl
> Inserting fact: 3
> Inserting fact: 1
> Inserting fact: 2
> Number found with value: 1
> Number found with value: 3
> Number found with value: 2
>
>
> Can someone  reproduce this behavior?? It seams absolutely strange to me.
> I would have expected the order 1,2,3. Any explanations?
>
> Thanks in advance for helping me!
>
>
>
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