Hi,

I'm trying to load drts in a serialized fashion and executing it. During execution, I get the error as mentioned below.

But if I keep the package name different for both the drts, the same code works fine.

Find below the errors and code snippets :

Files Used :

1. Main.java
2. SchemeEngine.java
3. PurchaseOrder.java
4. PurchaseOrderImpl.java
5. SchemeHelper.java
6. ON_PO_PROD_PACK_PER_DISC.drt
7. ON_PO_PROD_DIS.drt

Main.java

*

• To change this template, choose Tools | Templates
• and open the template in the editor.
  */

package test;

import app.PurchaseOrder;
import app.PurchaseOrderImpl;
import java.util.ArrayList;
import java.util.List;
import scheme.SchemeEngine;

/**
*

• @author msuser1
  */
  public class Main {

/**

• @param args the command line arguments
  */
  public static void testCrazyBug() throws Exception {

// String[] drts = new String[]

{"/ON_PO_PROD_DIS.drt", "/ON_PO_PROD_PACK_PER_DISC.drt", "/ON_PO_PROD_PACK_PER_DISC_using_function.drt"}

;
// String[] xls = new String[]

{"/ON_PO_PROD_DISC_1.xls", "/ON_PO_PROD_PACK_PER_DISC.xls", "/ON_PO_PROD_PACK_PER_DISC_using_function.xls"}

;

String[] drts = new String[]

{"/ON_PO_PROD_DIS.drt", "/ON_PO_PROD_PACK_PER_DISC.drt"}

;
String[] xls = new String[]

{"/ON_PO_PROD_DISC_1.xls", "/ON_PO_PROD_PACK_PER_DISC.xls"}

;

PurchaseOrder po = new PurchaseOrderImpl();

System.out.println("length of drt " + drts.length);
SchemeEngine engineDirect = new SchemeEngine(PurchaseOrderImpl.class.getClassLoader());
for (int i = 0; i < drts.length; i++)

{ engineDirect.loadSchemeFromDRT(drts[i], xls[i]); }

System.out.println("Applying Schemes in normal mode");
engineDirect.applyOnPurchaseOrder(po);

List serializedList = new ArrayList();
for (int i = 0; i < drts.length; i++)

{ SchemeEngine engineLocal = new SchemeEngine(PurchaseOrderImpl.class.getClassLoader()); engineLocal.loadSchemeFromDRT(drts[i], xls[i]); byte[] blobBytes = engineLocal.serializeDefinition(); serializedList.add(blobBytes); }

SchemeEngine engineOptimized = new SchemeEngine(PurchaseOrderImpl.class.getClassLoader());
for (int i = 0; i < drts.length; i++)

{ engineOptimized.loadSerializedDefinition((byte[]) serializedList.get(i)); }

try

{ System.out.println("Applying Schemes in optmized mode"); engineOptimized.applyOnPurchaseOrder(po); }

catch (Exception e)

{ e.printStackTrace(); }

}

public static void main(String args[]) throws Exception { testCrazyBug(); }


}

SchemeEngine.java

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package scheme;

import app.*;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseConfiguration;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.DecisionTableConfiguration;
import org.drools.builder.DecisionTableInputType;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.common.DroolsObjectInputStream;
import org.drools.common.DroolsObjectOutputStream;
import org.drools.decisiontable.ExternalSpreadsheetCompiler;
import org.drools.decisiontable.InputType;
import org.drools.definition.KnowledgePackage;
import org.drools.io.ResourceFactory;
import org.drools.runtime.StatelessKnowledgeSession;
import org.drools.template.parser.DataListener;
import org.drools.template.parser.TemplateDataListener;

/**
*
* @author msuser1
*/
public class SchemeEngine {

private KnowledgeBase kbase = null;
private ClassLoader classLoader = null;

public SchemeEngine(ClassLoader cl) { this.classLoader = cl; KnowledgeBaseConfiguration kbc = KnowledgeBaseFactory.newKnowledgeBaseConfiguration(new Properties(), this.classLoader); kbase = KnowledgeBaseFactory.newKnowledgeBase(kbc); }

public void loadSchemeFromDRL(String drlFileName) {
DecisionTableConfiguration dtableconfiguration = KnowledgeBuilderFactory.newDecisionTableConfiguration();
dtableconfiguration.setInputType(DecisionTableInputType.XLS);

KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(ResourceFactory.newClassPathResource(drlFileName, SchemeEngine.class),
ResourceType.DRL);

if (kbuilder.hasErrors()) { System.err.println(kbuilder.getErrors().toString()); }
kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
}

public void loadSchemeFromXLS(String xlsFileName) {
DecisionTableConfiguration dtableconfiguration = KnowledgeBuilderFactory.newDecisionTableConfiguration();
dtableconfiguration.setInputType(DecisionTableInputType.XLS);

KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(ResourceFactory.newClassPathResource(xlsFileName, SchemeEngine.class),
ResourceType.DTABLE, dtableconfiguration);

if (kbuilder.hasErrors()) { System.err.println(kbuilder.getErrors().toString()); }
kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
}

public void loadSchemeFromDRT(String drtFileName, String xlsFileName) throws Exception { loadSchemeFromDRT(drtFileName, xlsFileName, 1, 1); }

public void loadSchemeFromDRT(String drtFileName, String xlsFileName, int startingRow, int startingColumn) throws Exception { InputStream drtInput = SchemeEngine.class.getResourceAsStream(drtFileName); ByteArrayOutputStream drtOut = new ByteArrayOutputStream(); writeToStream(drtInput, drtOut); InputStream xlsInput = SchemeEngine.class.getResourceAsStream(xlsFileName); ByteArrayOutputStream xlsOut = new ByteArrayOutputStream(); writeToStream(xlsInput, xlsOut); loadSchemeFromDRT(drtOut.toByteArray(), xlsOut.toByteArray(), startingRow, startingColumn); }

private void writeToStream(InputStream in, OutputStream out) throws IOException {
byte[] buf = new byte[4 * 1024];
int numRead = 0;
while ((numRead = in.read(buf)) >= 0) { out.write(buf, 0, numRead); }
}

public void loadSchemeFromDRT(byte[] drtContent, byte[] xlsContent) { loadSchemeFromDRT(drtContent, xlsContent, 1, 1); }

public void loadSchemeFromDRT(byte[] drtContent, byte[] xlsContent, int startingRow, int startingColumn) {

final ExternalSpreadsheetCompiler converter = new ExternalSpreadsheetCompiler();
final List<DataListener> listeners = new ArrayList<DataListener>();
InputStream in = new ByteArrayInputStream(drtContent);

TemplateDataListener listener = new TemplateDataListener(3, 1, in);
listeners.add(listener);
converter.compile(new ByteArrayInputStream(xlsContent), InputType.XLS, listeners);

KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(ResourceFactory.newByteArrayResource(listener.renderDRL().getBytes()),
ResourceType.DRL);

if (kbuilder.hasErrors()) { System.err.println(kbuilder.getErrors().toString()); }
kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
}

public byte[] serializeDefinition() {
DroolsObjectOutputStream dos = null;
ByteArrayOutputStream bos = null;
try { bos = new ByteArrayOutputStream(); dos = new DroolsObjectOutputStream(bos); dos.writeObject(kbase.getKnowledgePackages()); return bos.toByteArray(); } catch (IOException ex) { Logger.getLogger(SchemeEngine.class.getName()).log(Level.SEVERE, null, ex); return null; } finally {
try { dos.close(); bos.close(); } catch (IOException ex) { Logger.getLogger(SchemeEngine.class.getName()).log(Level.SEVERE, null, ex); }
}
}

public void loadSerializedDefinition(byte[] serializedContent) {
try { DroolsObjectInputStream dis = null; ByteArrayInputStream bis = null; bis = new ByteArrayInputStream(serializedContent); dis = new DroolsObjectInputStream(bis); Collection<KnowledgePackage> defn = (Collection<KnowledgePackage>)dis.readObject(); kbase.addKnowledgePackages(defn); } catch (ClassNotFoundException ex) { Logger.getLogger(SchemeEngine.class.getName()).log(Level.SEVERE, null, ex); } catch (IOException ex) { Logger.getLogger(SchemeEngine.class.getName()).log(Level.SEVERE, null, ex); }
}

public void applyOnPurchaseOrder(PurchaseOrder purchaseOrder) {
if (kbase.getKnowledgePackages().size() == 0) { throw new RuntimeException("No Schemes are loaded."); }
List objects = new ArrayList();
objects.add(purchaseOrder);
if (purchaseOrder.orderDetails() != null && purchaseOrder.orderDetails().size() > 0) {
Iterator iter = purchaseOrder.orderDetails().iterator();
while (iter.hasNext()) { PurchaseOrderDetail detail = (PurchaseOrderDetail) iter.next(); objects.add(detail); }
}
StatelessKnowledgeSession session = kbase.newStatelessKnowledgeSession();
session.execute(Arrays.asList(objects.toArray()));
}

public void applyRule(Object[] objects) {
if (kbase.getKnowledgePackages().size() == 0) { throw new RuntimeException("No Schemes are loaded."); }
StatelessKnowledgeSession session = kbase.newStatelessKnowledgeSession();
session.execute(Arrays.asList(objects));
}

public static void main(String[] args) {
}
}

PurchaseOrder.java

package app;

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/



import java.util.Date;
import java.util.List;

/**
*
* @author msuser1
*/
public interface PurchaseOrder {
public Float orderAmount();
public Date orderDate();
public Integer orderDay();
public List orderDetails();
public boolean belongsToGeoHierarchy(String nodeName);
public void addFreeItem(String schemeId, String skuId, int qty);
public void addFlatDiscount(String SchemeId, Float discountAmt);
public void addPercentageDiscount(String SchemeId, Float discountPercent);
public void addFlatDiscountForItem(String SchemeId, String skuId, Float discountAmt);
public void addPercentageDiscountForItem(String SchemeId, String skuId, Float discountPercent);
public void addPercentageDiscountPerUomForItem(String SchemeId, String skuId, Float discountPercent);
public void addInternalGiftVoucher(String SchemeId, Float voucherAmt);
public void addExternalGiftVoucher(String SchemeId, Float voucherAmt, String externalVendorId);
public void addInternalGiftVoucherForItem(String SchemeId, String skuId, Float voucherAmt);
public void addExternalGiftVoucherForItem(String SchemeId, String skuId, Float voucherAmt, String externalVendorId);
public void addRewardPoint(String SchemeId, int rewardPoint);
public void addRewardPointForItem(String SchemeId, String skuId, int rewardPoint);
public void addWeightBasedFlatDiscountPerUomForItem(String SchemeId, String skuId, Float discount_amt, String uomId);
public Boolean immediatePayment();
public Boolean regularPurchase();
public Boolean consignmentPurchase();
public Boolean cat2ConsignmentPurchase();
public Boolean cat3ConsignmentPurchase();
public Boolean intransitPurchase();
public Boolean skuPresent(String skuId);
public Integer materialQuantityForItem(String skuId);
public Boolean schemeApplied(String schemeDefinitionId);
public void addDetail(PurchaseOrderDetail prd);
}
=========================================================================================================================

PurchaseOrderImpl.java

package app;

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
*
* @author msuser1
*/
public class PurchaseOrderImpl implements PurchaseOrder {
private List details = new ArrayList();

public Date orderDate() {
try { DateFormat fmt = new SimpleDateFormat("yyyy-dd-MM"); Date dt = fmt.parse("2009-06-23"); return dt; } catch (ParseException ex) { Logger.getLogger(PurchaseOrderImpl.class.getName()).log(Level.SEVERE, null, ex); return null; }
}

public Integer orderDay(){ return 10; }

public List orderDetails() { return details; }

public boolean belongsToGeoHierarchy(String nodeName) { return true; }

public void addFreeItem(String schemeId, String skuId, int qty) { System.out.println("Add Free Item"); }

public void addFlatDiscount(String SchemeId, Long discountAmt) { System.out.println("Add Flat Discount"); }

public void addPercentageDiscount(String SchemeId, int discountPercent) { System.out.println("Add Percentage Discount"); }

public void addFlatDiscountForItem(String SchemeId, String skuId, Long discountAmt) { System.out.println("Add Flat Discount For Item"); }

public void addPercentageDiscountForItem(String SchemeId, String skuId, int discountPercent) { System.out.println("Add Percentage Discount For Item"); }

public void addPercentageDiscountPerUomForItem(String SchemeId, String skuId, int discountPercent) { System.out.println("Add Percentage Discount For Uom For Item"); }

public void addInternalGiftVoucher(String SchemeId, Long voucherAmt) { System.out.println("Add Internal Gift Voucher"); }

public void addExternalGiftVoucher(String SchemeId, Long voucherAmt, String externalVendorId) { System.out.println("Add External Gift Voucher"); }

public void addInternalGiftVoucherForItem(String SchemeId, String skuId, Long voucherAmt) { System.out.println("Add Internal Gift Voucher For Item"); }

public void addExternalGiftVoucherForItem(String SchemeId, String skuId, Long voucherAmt, String externalVendorId) { System.out.println("Add External Gift Voucher For Item"); }

public void addRewardPoint(String SchemeId, int rewardPoint) { System.out.println("Add Reward Point"); }

public void addRewardPointForItem(String SchemeId, String skuId, int rewardPoint) { System.out.println("Add Reward Point For Item"); }

public Boolean immediatePayment(){ return true; }

public Boolean regularPurchase() { return true; }

public Boolean consignmentPurchase() { return false; }

public Boolean cat2ConsignmentPurchase() { return false; }

public Boolean cat3ConsignmentPurchase() { return false; }

public Boolean commissionPurchase() { return false; }

public Boolean intransitPurchase() { return false; }

public Boolean skuPresent(String skuId) { return false; }

public Integer materialQuantityForItem(String skuId) { return 10; }

public Boolean schemeApplied(String schemeDefinitionId) { return false; }

public void addWeightBasedFlatDiscountPerUomForItem(String SchemeId, String skuId, Long discount_amt, String uomId) { throw new UnsupportedOperationException("Not supported yet."); }
public void addDetail(PurchaseOrderDetail pod)
{ details.add(pod); }

public void addFlatDiscount(String SchemeId, Float discountAmt) { throw new UnsupportedOperationException("Not supported yet."); }

public void addFlatDiscountForItem(String SchemeId, String skuId, Float discountAmt) { throw new UnsupportedOperationException("Not supported yet."); }

public Float orderAmount() { throw new UnsupportedOperationException("Not supported yet."); }

public void addPercentageDiscount(String SchemeId, Float discountPercent) { throw new UnsupportedOperationException("Not supported yet."); }

public void addPercentageDiscountForItem(String SchemeId, String skuId, Float discountPercent) { throw new UnsupportedOperationException("Not supported yet."); }

public void addPercentageDiscountPerUomForItem(String SchemeId, String skuId, Float discountPercent) { throw new UnsupportedOperationException("Not supported yet."); }

public void addInternalGiftVoucher(String SchemeId, Float voucherAmt) { throw new UnsupportedOperationException("Not supported yet."); }

public void addExternalGiftVoucher(String SchemeId, Float voucherAmt, String externalVendorId) { throw new UnsupportedOperationException("Not supported yet."); }

public void addInternalGiftVoucherForItem(String SchemeId, String skuId, Float voucherAmt) { throw new UnsupportedOperationException("Not supported yet."); }

public void addExternalGiftVoucherForItem(String SchemeId, String skuId, Float voucherAmt, String externalVendorId) { throw new UnsupportedOperationException("Not supported yet."); }

public void addWeightBasedFlatDiscountPerUomForItem(String SchemeId, String skuId, Float discount_amt, String uomId) { throw new UnsupportedOperationException("Not supported yet."); }
}

SchemeHelper.java


/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package helper;

import app.PurchaseOrder;
import app.PurchaseOrderDetail;
import java.lang.Float;

/**
*
* @author msuser1
*/
public class SchemeHelper {

public static boolean belongsToProductHierarchy(String skuId, String nodeName) { return false; //Sku.belongsToProductHierarchy(nodeName); }

public static Integer materialQuantityForItem(PurchaseOrder po, String skuId) { return po.materialQuantityForItem(skuId); }

public static boolean productIdOrProductAncestorMatching(PurchaseOrderDetail poDetail, String productId) {
System.out.println("Inside the method......................################################");
boolean result = false;
try { result = poDetail.productId().compareTo(productId) == 0 || poDetail.belongsToAncestorProduct(productId).booleanValue(); } catch (Exception e) { e.printStackTrace(); }

return result;
}

public static boolean complexMethod(PurchaseOrderDetail poDetail, String productId, String packId) {
boolean result = false;
try

{ result = (poDetail.packId().compareTo(packId) == 0 || poDetail.belongsToAncestorPack(packId).booleanValue()) && (poDetail.productId().compareTo(productId) == 0 || poDetail.belongsToAncestorProduct(productId).booleanValue()); }

catch (Exception ex)

{ ex.printStackTrace(); }

return result;
}
}

ON_PO_PROD_DIS.drt

template header
SchemeID
ProductID
Discount

package app;
import function helper.SchemeHelper.*

template "Scheme"
rule "po_@

{SchemeID}_@{row.rowNumber}"
when
$order : PurchaseOrder()
$orderDetail : PurchaseOrderDetail($det : this,eval($det.productId().compareTo("@{ProductID}") == 0 || $det.belongsToAncestorProduct("@{ProductID}") == true), purchaseOrder == $order)
then
float disAmt=0;
disAmt = $orderDetail.saleableQty() * @{Discount}F;
System.out.println("Discount amount = @{Discount}..XXXX..........." + disAmt);
$order.addFlatDiscountForItem("@{SchemeID}

",$orderDetail.skuId(), disAmt);
end

end template

ON_PO_PROD_PACK_PER_DISC.drt

template header
SchemeID
ProductID
PackID
Discount

package app;
import app.*;
import function helper.SchemeHelper.*

template "Scheme"
rule "ON_PO_PROD_PACK_PER_DISC_@

{row.rowNumber}

"
when
$order: PurchaseOrder()
$orderDetail : PurchaseOrderDetail($det : this, eval(
($det.belongsToAncestorPack("@

{PackID}") == true || $det.packId().compareTo("@{PackID}

") == 0)
&&
($det.productId().compareTo("@

{ProductID}") == 0 || $det.belongsToAncestorProduct("@{ProductID}

") == true)
) , purchaseOrder == $order)
then
float disAmt=0;
disAmt = ($orderDetail.materialPrice() * $orderDetail.saleableQty()) * @

{Discount}

F/100;
System.out.println("Discount amount = XXXX..........." + disAmt);
$order.addFlatDiscountForItem("@

{SchemeID}

",$orderDetail.skuId(), disAmt);
end

end template

Error :

java.lang.NullPointerException
at org.drools.base.ClassFieldReader.getIndex(ClassFieldReader.java:78)
at org.drools.util.LeftTupleIndexHashTable.<init>(LeftTupleIndexHashTable.java:48)
at org.drools.util.LeftTupleIndexHashTable.<init>(LeftTupleIndexHashTable.java:35)
at org.drools.common.SingleBetaConstraints.createBetaMemory(SingleBetaConstraints.java:172)
at org.drools.reteoo.BetaNode.createMemory(BetaNode.java:340)
at org.drools.common.ConcurrentNodeMemories.createNodeMemory(ConcurrentNodeMemories.java:96)
at org.drools.common.ConcurrentNodeMemories.getNodeMemory(ConcurrentNodeMemories.java:75)
at org.drools.common.AbstractWorkingMemory.getNodeMemory(AbstractWorkingMemory.java:1534)
at org.drools.reteoo.JoinNode.assertLeftTuple(JoinNode.java:103)
at org.drools.reteoo.CompositeLeftTupleSinkAdapter.doPropagateAssertLeftTuple(CompositeLeftTupleSinkAdapter.java:145)
at org.drools.reteoo.CompositeLeftTupleSinkAdapter.createAndPropagateAssertLeftTuple(CompositeLeftTupleSinkAdapter.java:57)
at org.drools.reteoo.LeftInputAdapterNode.assertObject(LeftInputAdapterNode.java:142)
at org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:42)
at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:185)
at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:146)
at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1046)
at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1001)
at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:788)
at org.drools.impl.StatelessKnowledgeSessionImpl.execute(StatelessKnowledgeSessionImpl.java:259)
at scheme.SchemeEngine.applyOnPurchaseOrder(SchemeEngine.java:178)
at test.Main.testCrazyBug(Main.java:55)
at test.Main.main(Main.java:64)