How to use org.drools

protected StatefulKnowledgeSession initNewKnowledgeSession() {
 StatefulKnowledgeSession session = kbase.newStatefulKnowledgeSession();
 for ( int i = 0; i < columnList.length; i++ ) {
  session.insert( columnList[i] );
 }
 session.fireAllRules();
 return session;
}

public void execute() throws Exception {
 if ( kbase != null ) {
  StatefulKnowledgeSession session = kbase.newStatefulKnowledgeSession();
  for ( Row row : rowList ) {
   session.insert( row );
  }
  session.fireAllRules();
  Collection<Object> oList = session.getObjects( new ObjectFilter() {
   @Override
   public boolean accept( Object o ) {
    if ( o instanceof Row && !( (Row) o ).isExternalSource() ) {
     return true;
    }
    return false;
   }
  } );
  for ( Object o : oList ) {
   resultList.add( (Row) o );
  }
  session.dispose();
 }
}

public void initializeRules() {
 // To ensure the plugin classloader use for dependency resolution
 ClassLoader orig = Thread.currentThread().getContextClassLoader();
 ClassLoader loader = getClass().getClassLoader();
 Thread.currentThread().setContextClassLoader( loader );
 Resource ruleSet = null;
 if ( ruleString != null ) {
  ruleSet = ResourceFactory.newReaderResource( new StringReader( ruleString ) );
 } else {
  ruleSet = ResourceFactory.newFileResource( ruleFilePath );
 }
 kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
 kbuilder.add( ruleSet, ResourceType.DRL );
 if ( kbuilder.hasErrors() ) {
  System.out.println( kbuilder.getErrors().toString() );
  throw new RuntimeException( BaseMessages.getString( PKG, "RulesData.Error.CompileDRL" ) );
 }
 Collection<KnowledgePackage> pkgs = kbuilder.getKnowledgePackages();
 kbase = KnowledgeBaseFactory.newKnowledgeBase();
 // Cache the knowledge base as its creation is intensive
 kbase.addKnowledgePackages( pkgs );
 // reset classloader back to original
 Thread.currentThread().setContextClassLoader( orig );
}

/**
 * Create a new KnowledgeBase using the given KnowledgeBaseConfiguration
 * @return
 *     The KnowledgeBase
 */
public static KnowledgeBase newKnowledgeBase(KnowledgeBaseConfiguration conf) {
  return getKnowledgeBaseFactoryService().newKnowledgeBase( conf );
}

/**
 * Create a KnowledgeSessionConfiguration on which properties can be set.
 * @return
 *     The KnowledgeSessionConfiguration.
 */
public static KnowledgeSessionConfiguration newKnowledgeSessionConfiguration(Properties properties) {
  return getKnowledgeBaseFactoryService().newKnowledgeSessionConfiguration( properties );
}

/**
 * Create a KnowledgeBaseConfiguration on which properties can be set.
 * @return
 *     The KnowledgeBaseConfiguration.
 */
public static KnowledgeBaseConfiguration newKnowledgeBaseConfiguration() {
  return getKnowledgeBaseFactoryService().newKnowledgeBaseConfiguration();
}

/**
 * Get the SystemEventListener
 * @return
 */
public static SystemEventListener getSystemEventListener() {
  return getSystemEventListenerService().getSystemEventListener();
}

/**
 * Set the SystemEventListener
 * 
 * @param listener
 */
public static void setSystemEventListener(SystemEventListener listener) {
  getSystemEventListenerService().setSystemEventListener( listener );
}

public void initializeRules() {
 // To ensure the plugin classloader use for dependency resolution
 ClassLoader orig = Thread.currentThread().getContextClassLoader();
 ClassLoader loader = getClass().getClassLoader();
 Thread.currentThread().setContextClassLoader( loader );
 Resource ruleSet = null;
 if ( ruleString != null ) {
  ruleSet = ResourceFactory.newReaderResource( new StringReader( ruleString ) );
 } else {
  ruleSet = ResourceFactory.newFileResource( ruleFilePath );
 }
 kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
 kbuilder.add( ruleSet, ResourceType.DRL );
 if ( kbuilder.hasErrors() ) {
  System.out.println( kbuilder.getErrors().toString() );
  throw new RuntimeException( BaseMessages.getString( PKG, "RulesData.Error.CompileDRL" ) );
 }
 Collection<KnowledgePackage> pkgs = kbuilder.getKnowledgePackages();
 kbase = KnowledgeBaseFactory.newKnowledgeBase();
 // Cache the knowledge base as its creation is intensive
 kbase.addKnowledgePackages( pkgs );
 // reset classloader back to original
 Thread.currentThread().setContextClassLoader( orig );
}

/**
 * Create a new KnowledgeBase using the given KnowledgeBaseConfiguration
 * @return
 *     The KnowledgeBase
 */
public static KnowledgeBase newKnowledgeBase(KnowledgeBaseConfiguration conf) {
  return getKnowledgeBaseFactoryService().newKnowledgeBase( conf );
}

/**
 * Create a KnowledgeSessionConfiguration on which properties can be set.
 * @return
 *     The KnowledgeSessionConfiguration.
 */
public static KnowledgeSessionConfiguration newKnowledgeSessionConfiguration() {
  return getKnowledgeBaseFactoryService().newKnowledgeSessionConfiguration();
}

/**
 * Create a KnowledgeBaseConfiguration on which properties can be set.
 * @return
 *     The KnowledgeBaseConfiguration.
 */
public static KnowledgeBaseConfiguration newKnowledgeBaseConfiguration() {
  return getKnowledgeBaseFactoryService().newKnowledgeBaseConfiguration();
}

/**
 * Get the SystemEventListener
 * @return
 */
public static SystemEventListener getSystemEventListener() {
  return getSystemEventListenerService().getSystemEventListener();
}

/**
 * Set the SystemEventListener
 * 
 * @param listener
 */
public static void setSystemEventListener(SystemEventListener listener) {
  getSystemEventListenerService().setSystemEventListener( listener );
}

/**
 * Create a new KnowledgeBase using the default KnowledgeBaseConfiguration
 * @return
 *     The KnowledgeBase
 */
public static KnowledgeBase newKnowledgeBase() {
  return getKnowledgeBaseFactoryService().newKnowledgeBase();
}

/**
 * Create a KnowledgeSessionConfiguration on which properties can be set.
 * @return
 *     The KnowledgeSessionConfiguration.
 */
public static KnowledgeSessionConfiguration newKnowledgeSessionConfiguration(Properties properties) {
  return getKnowledgeBaseFactoryService().newKnowledgeSessionConfiguration( properties );
}

/**
 * Create a KnowledgeBaseConfiguration on which properties can be set. Use
 * the given properties file and ClassLoader - either of which can be null.
 * @return
 *     The KnowledgeBaseConfiguration.
 */
public static KnowledgeBaseConfiguration newKnowledgeBaseConfiguration(Properties properties,
                                    ClassLoader... classLoaders) {
  return getKnowledgeBaseFactoryService().newKnowledgeBaseConfiguration( properties,
                                      classLoaders );
}

/**
 * Create a new KnowledgeBase using the default KnowledgeBaseConfiguration
 * @return
 *     The KnowledgeBase
 */
public static KnowledgeBase newKnowledgeBase() {
  return getKnowledgeBaseFactoryService().newKnowledgeBase();
}

/**
 * Create a KnowledgeSessionConfiguration on which properties can be set.
 * @return
 *     The KnowledgeSessionConfiguration.
 */
public static KnowledgeSessionConfiguration newKnowledgeSessionConfiguration(Properties properties) {
  return getKnowledgeBaseFactoryService().newKnowledgeSessionConfiguration( properties );
}

/**
 * Create a KnowledgeSessionConfiguration on which properties can be set.
 * @return
 *     The KnowledgeSessionConfiguration.
 */
public static KnowledgeSessionConfiguration newKnowledgeSessionConfiguration() {
  return getKnowledgeBaseFactoryService().newKnowledgeSessionConfiguration();
}