The simplist solution is just to change your condition to be $a : Applicant(age < 18, valid != false) Thomas From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Esteban Aliverti Sent: 20 January 2012 14:20 To: Rules Users List Subject: Re: [rules-users] Infinit loop in simple example import spikes.Applicant rule "Is of valid age" when $a : Applicant( age < 18 ) then modify( $a ) { valid = false }; end By using modify() you are telling the engine that $a was modified in some way. This causes the re-evaluation of your rule, and since $a.age is still < 18, then the rule is activated and fired infinite times. Read the documentation manual about some attributes you can use in your rules to avoid this behavior: no-loop, lock-on-active. Best Regards, XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Esteban Aliverti - Developer @ http://www.plugtree.com - Blog @ http://ilesteban.wordpress.com On Fri, Jan 20, 2012 at 3:12 PM, roland.kofler <roland.kofler@gmail.com<mailto:roland.kofler@gmail.com>> wrote: Simple example loops ad infinitum if executed: package spikes; import org.springframework.roo.addon.javabean.RooJavaBean; @RooJavaBean public class Applicant { private final String string; private final int age; public boolean valid=true; public Applicant(String string, int i) { this.string = string; this.age = i; } } DroolsSpikeTest package spikes; import static org.junit.Assert.*; import org.drools.KnowledgeBase; import org.drools.runtime.StatelessKnowledgeSession; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(locations={"classpath:**/applicationContext-drools.xml"}) public class DroolsSpikeTest { @Autowired private KnowledgeBase kbase; @Test public void testspikeDroolRule() { StatelessKnowledgeSession ksession = kbase.newStatelessKnowledgeSession(); Applicant a = new Applicant("Mr John Smith", 16); assertTrue(a.isValid()); ksession.execute(a); assertFalse(a.isValid()); } } applicationContext-drools.xml <?xml version="1.0" encoding="UTF-8" standalone="no"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:drools="http://drools.org/schema/drools-spring" xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd http://drools.org/schema/drools-spring http://anonsvn.jboss.org/repos/labs/labs/jbossrules/trunk/drools-containe... <drools:kbase id="kbase1"> <drools:resources> <drools:resource id="licenseRule" type="DRL" source="classpath:spikes/licenseApplication.drl"/> </drools:resources> <drools:configuration> <drools:mbeans enabled="true" /> </drools:configuration> </drools:kbase> <drools:ksession kbase="kbase1" type="stateless" id="ksessionStateless" name="stateless1" > </drools:ksession> </beans> licenseApplication.drl import spikes.Applicant rule "Is of valid age" when $a : Applicant( age < 18 ) then modify( $a ) { valid = false }; end -- View this message in context: http://drools.46999.n3.nabble.com/Infinit-loop-in-simple-example-tp367553... 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