JBoss Community

Hi!

I'm trying to create an example Drools file but when I run it I have this error message:

Unable to create Field Extractor for 'contenuto' of '[ClassObjectType class="java".lang.Object]' in rule 'prova' : [Rule name='prova']

java.lang.IllegalArgumentException: Could not parse knowledge.

          at org.drools.builder.impl.KnowledgeBuilderImpl.newKnowledgeBase(KnowledgeBuilderImpl.java:58)

          at com.sample.ProcessTest.readKnowledgeBase(ProcessTest.java:43)

          at com.sample.ProcessTest.main(ProcessTest.java:21)

this is my drools file (named Rule.drl):

package com.googlecode.cursos.jbpm

import org.drools.runtime.process.WorkflowProcessInstance;

import org.sample.model.MyObject;

rule "prova"

          ruleflow-group "regole"

          when

                    $o: Object(contenuto == "rosa")

          then

           System.out.println("prima regola");

end

this is my ProcessTest.java class:

public class ProcessTest {

          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");

                              MyObject obj = new MyObject();

                              obj.setContenuto("rosa");

                              obj.setId(1);

                              ksession.insert(obj);

                              // start a new process instance

                              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("sample.bpmn"), ResourceType.BPMN2);

  kbuilder.add(ResourceFactory.newClassPathResource("Rule.drl"), ResourceType.DRL);

  return kbuilder.newKnowledgeBase();

  }

and this is my MyObject.java class:

package org.sample.model;

public class MyObject {

          String contenuto;

          int id;

          public int getId() { return id;}

public void setId(int id) { this.id = id; }

public String getContenuto() { return contenuto; }

public void setContenuto(String contenuto) { this.contenuto = contenuto;}

}

I can't understand where is the problem :(

could anyone help me please?

thank you!