11:49 a.m.
For some reason I cannot get the most basic rule to fire from a flow.
Not sure what is going on, but would appreciate some help. This is in
Drools 5.1.0.M1.
I pretty much followed the example at
http://www.developer.com/java/ent/article.php/10933_3821101_4/Rev-Up-the
-Drools-5-Java-Rule-Engine.htm, but it did not work for me. I don't
get an error message and I don't see the rule fire and print the
system.out.
.rf
<?xml version="1.0" encoding="UTF-8"?>
<process xmlns="http://drools.org/drools-5.0/process"
xmlns:xs="http://www.w3.org/2001/XMLSchema-instance"
xs:schemaLocation="http://drools.org/drools-5.0/process
drools-processes-5.0.xsd"
type="RuleFlow" name="flow"
id="com.sample.bpmn.hello"
package-name="com.sample">
<header>
</header>
<nodes>
<end id="4" name="End" x="561" y="140"
width="48" height="48" />
<start id="1" name="Start" x="66" y="88"
width="48" height="48" />
<ruleSet id="3" name="Rule" x="368" y="159"
width="80" height="48"
ruleFlowGroup="helloGroup" />
</nodes>
<connections>
<connection from="3" to="4" />
<connection from="1" to="3" />
</connections>
</process>
.dlr
package com.sample
import com.sample.DroolsTest.Message;
rule "Hello World Message"
ruleflow-group "helloGroup"
when
m : Message( status == Message.HELLO, myMessage : message )
then
System.out.println( myMessage + "***" );
m.setMessage( "Goodbye cruel world Message" );
m.setStatus( Message.GOODBYE );
update( m );
end
Java
package com.sample;
import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.bpmn2.xml.BPMNSemanticModule;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderConfiguration;
import org.drools.builder.KnowledgeBuilderError;
import org.drools.builder.KnowledgeBuilderErrors;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.compiler.PackageBuilderConfiguration;
import org.drools.io.ResourceFactory;
import org.drools.logger.KnowledgeRuntimeLogger;
import org.drools.logger.KnowledgeRuntimeLoggerFactory;
import org.drools.runtime.StatefulKnowledgeSession;
/**
* This is a sample class to launch a rule.
*/
public class DroolsTestFlowAndRule {
public static final void main(String[] args) {
try {
// load up the knowledge
base
KnowledgeBase kbase =
readKnowledgeBase();
StatefulKnowledgeSession
ksession = kbase.newStatefulKnowledgeSession();
KnowledgeRuntimeLogger
logger = KnowledgeRuntimeLoggerFactory.newFileLogger(ksession, "test");
// start a new process
instance'
Message message = new
Message();
message.setMessage("Hello World Message");
message.setStatus(Message.HELLO);
ksession.insert(message);
ksession.startProcess("com.sample.bpmn.hello");
ksession.fireAllRules();
logger.close();
} catch (Throwable t) {
t.printStackTrace();
}
}
private static KnowledgeBase readKnowledgeBase() throws
Exception {
KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(ResourceFactory.newClassPathResource("hello.rf"),
ResourceType.DRF);
kbuilder.add(ResourceFactory.newClassPathResource("Sample.drl"),
ResourceType.DRL);
KnowledgeBuilderErrors errors =
kbuilder.getErrors();
if (errors.size() > 0) {
for
(KnowledgeBuilderError error: errors) {
System.err.println(error);
}
throw new
IllegalArgumentException("Could not parse knowledge.");
}
KnowledgeBase kbase =
KnowledgeBaseFactory.newKnowledgeBase();
kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
return kbase;
}
public static class Message {
public static final int HELLO = 0;
public static final int GOODBYE = 1;
private String message;
private int status;
public String getMessage() {
return this.message;
}
public void setMessage(String message) {
this.message = message;
}
public int getStatus() {
return this.status;
}
public void setStatus(int status) {
this.status = status;
}
}
}