Well, I'm not sure why are you constraining your rule using the class Object. What is happening is that the engine always inserts a fact into the engine known as InitialFact, that as all objects in java, is a subclass of Object, and that is why the rule fires. If instead of Object, you use a different class, like Integer for instance, to constrain your rule, you will get the behavior you are looking for. []s Edson 2007/8/22, Dean Jones < dean.m.jones(a)gmail.com&gt;: > > Hi, > > I have the following simple rulebase: > > package org.drools.examples > rule "Hello World" > when > o : Object( ) > then > System.out.println("Hello world (o=" + o + ")"); > end > rule "Goodbye World" > when > not Object( ) > then > System.out.println("Goodbye cruel world"); > end > > and the following code: > > public class TestReadRuleFile { > > public static void main(String[] args) throws Exception { > PackageBuilder builder = new PackageBuilder(); > builder.addPackageFromDrl( > new InputStreamReader( > TestReadRuleFile.class.getResourceAsStream ("test.drl"))); > Package pkg = builder.getPackage(); > RuleBase rulebase = RuleBaseFactory.newRuleBase(); > rulebase.addPackage(pkg); > StatefulSession session = rulebase.newStatefulSession(); > session.fireAllRules(); > } > > } > > which produces the following output: > > Hello world (o=org.drools.reteoo.InitialFactImpl@4dde85f0) > > I expected the "Goodbye World" rule to fire, as there should not be > any Objects in the working memory. If I change my code to insert an > object into the working memory as follows: > > session.insert(new Object()); > > I now get the following output: > > Hello world (o=org.drools.reteoo.InitialFactImpl@4dde85f0 ) > Hello world (o=java.lang.Object@17ba38f) > > In this case, I expected the "Hello World" rule to fire only once. Any > thoughts on what I'm doing wrong here? > > Thanks, > > Dean. > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > -- Edson Tirelli Software Engineer - JBoss Rules Core Developer Office: +55 11 3529-6000 Mobile: +55 11 9287-5646 JBoss, a division of Red Hat @ www.jboss.com _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users