can functions be used in rule's when part?
by Abarna Ramachandran
I really appreciate your help. I understand my mistake. I have another
question. Can i use a fact as a parameter for function defined in the rule
and make a call to that function in the when part of the rule.
For example something like this
rule CheckStationNumber
when
AssertionObject(getRecord(AssertionObject).getStationNo() == null)
then
error("station number should not be null",log);
end
thanks
Abarna
2009/8/1 Wolfgang Laun <wolfgang.laun(a)gmail.com>
> The global ao must be assigned to the ksession, from your Java code, by
> calling
> ksession.setGlobal( "ao", assertionObject )
> before you do anything that triggers LHS evaluations. See Drools Expert,
> section 4.5.2.
>
> The WM and rule setup as you present it does not make sense (to me). If you
> insert an AssertionObject as a WM fact, you shouldn't have it as a global.
> If you want it as a fact, you'll need rules with patterns like
> when
> AssertionObject(...)
> And the same goes for BillingRecord
>
> -W
>
>
> 2009/8/1 Abarna Ramachandran <rabarna(a)archstone.in>
>
>> I am getting the following error when trying to insert my object into
>> ksession. I have attached my rules and java object. Please help me in
>> debugging why this is happening. I am using java 5 and drools 5.0
>>
>> thanks
>>
>> *error while inserting:*
>>
>> org.drools.RuntimeDroolsException:
>> defaultpkg.Rule_CheckStationNumber_0Eval0Invoker@e4aea391 :
>> java.lang.NullPointerException
>>
>> *rules.drl*
>> import java.lang.*;
>> import java.util.*;
>> import ct.fw.rules.*;
>> import ct.fw.utils.*;
>> import ct.fw.rules.*;
>> import ct.fw.logging.*;
>> import ct.fw.pf.dbi.*;
>> import ct.fw.pf.dao.*;
>> import ct.fw.pf.seq.*;
>> import ct.fw.pf.util.*;
>> import ct.fw.pf.vo.*;
>> import ct.fw.ex.*;
>> import org.apache.commons.lang.*;
>> import com.aa.gccp.domain.*;
>>
>> global ct.fw.rules.AssertionObject ao
>> global ct.fw.logging.SmartLogger log
>>
>> function BillingRecord getRecord(AssertionObject ao)
>> {
>> return (BillingRecord) ao.get(0);
>> }
>> function void debug(String msg,SmartLogger log)
>> {
>> log.debug(BusinessRulesValidator.class, msg);
>> }
>> function void error(String msg,SmartLogger log)
>> {
>> log.error(BusinessRulesValidator.class, msg);
>> System.out.println("Message from rules "+msg);
>> }
>>
>> rule CheckTrue
>> when
>> eval(true)
>> then
>> System.out.println("evaluating true");
>> end
>>
>> rule CheckTrue2
>> when
>> eval(true)
>> then
>> error("evaluating from rules2",log);
>> end
>>
>> rule CheckStationNumber
>> when
>> eval(((getRecord(ao)).getStationNo()) == null)
>> then
>> error("station number should not be null",log);
>> end
>>
>> *part where i load the rules and insert the facts. There is no error when
>> loading the rules.drl. That means no parsing errors. The error happens at
>> ksessio.insert(assertionObject).*
>>
>> public void assertRulesObject(AssertionObject assertionObject) throws
>> BusinessRuleException
>> {
>> long current = System.currentTimeMillis();
>> KnowledgeBase kbase = knowledgeBasesMap.get(rulesFileName);
>>
>> if (kbase == null)
>> {
>> kbase = knowledgeBasesMap.get(rulesFileName + DRL);
>> }
>>
>> if ((kbase == null) || ((current - lastRefreshedMilliseconds) >
>> refreshTimeMilliseconds))
>> {
>> if (rulesFileName.toLowerCase().indexOf(DRL) == -1)
>> {
>> kbase = load(rulesFileName + DRL);
>> }
>> else
>> {
>> kbase = load(rulesFileName);
>> }
>>
>> lastRefreshedMilliseconds = System.currentTimeMillis();
>> }
>> this.assertionObject = assertionObject;
>>
>> List assertionobjectslist = new ArrayList();
>> *// i am just doing this part just to make sure assertion object is not
>> null and i will get some answer. this part runs fine. *
>> if (assertionObject != null)
>> {
>> assertionobjectslist = assertionObject.getValidationObjects();
>> String StationNumber = ((BillingRecord)
>> assertionObject.get(0)).getStationNo();
>> System.out.println("Station Number in assertion object is " +
>> StationNumber);
>> }
>> else
>> {
>> System.out.println("Assertion Object is null");
>> }
>> System.out.println("The number of objects in assertionobject is "
>> + assertionobjectslist.size());
>>
>> try
>> {
>> StatefulKnowledgeSession ksession =
>> kbase.newStatefulKnowledgeSession();
>> *//the next line throws the exception*
>> ksession.insert(assertionObject);
>>
>> ksession.fireAllRules();
>> ksession.dispose();
>>
>> }
>> catch (RuntimeDroolsException e1)
>> {
>> throw new BusinessRuleException(e1.getMessage());
>> }
>>
>> businessRulesErrors = assertionObject.getBusinessRulesErrors();
>>
>> if (throwException)
>> {
>> if (!assertionObject.getBusinessRulesErrors().isEmpty())
>> {
>> throw new BusinessRuleException(businessRulesErrors);
>> }
>> }
>> }
>>
>>
>> Any help is appreciated. thanks
>>
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users(a)lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>>
>
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
17 years
- 4
- 4
org.drools.RuntimeDroolsException when inserting into Knowledge Session
by Abarna Ramachandran
I am getting the following error when trying to insert my object into
ksession. I have attached my rules and java object. Please help me in
debugging why this is happening. I am using java 5 and drools 5.0
thanks
*error while inserting:*
org.drools.RuntimeDroolsException:
defaultpkg.Rule_CheckStationNumber_0Eval0Invoker@e4aea391 :
java.lang.NullPointerException
*rules.drl*
import java.lang.*;
import java.util.*;
import ct.fw.rules.*;
import ct.fw.utils.*;
import ct.fw.rules.*;
import ct.fw.logging.*;
import ct.fw.pf.dbi.*;
import ct.fw.pf.dao.*;
import ct.fw.pf.seq.*;
import ct.fw.pf.util.*;
import ct.fw.pf.vo.*;
import ct.fw.ex.*;
import org.apache.commons.lang.*;
import com.aa.gccp.domain.*;
global ct.fw.rules.AssertionObject ao
global ct.fw.logging.SmartLogger log
function BillingRecord getRecord(AssertionObject ao)
{
return (BillingRecord) ao.get(0);
}
function void debug(String msg,SmartLogger log)
{
log.debug(BusinessRulesValidator.class, msg);
}
function void error(String msg,SmartLogger log)
{
log.error(BusinessRulesValidator.class, msg);
System.out.println("Message from rules "+msg);
}
rule CheckTrue
when
eval(true)
then
System.out.println("evaluating true");
end
rule CheckTrue2
when
eval(true)
then
error("evaluating from rules2",log);
end
rule CheckStationNumber
when
eval(((getRecord(ao)).getStationNo()) == null)
then
error("station number should not be null",log);
end
*part where i load the rules and insert the facts. There is no error when
loading the rules.drl. That means no parsing errors. The error happens at
ksessio.insert(assertionObject).*
public void assertRulesObject(AssertionObject assertionObject) throws
BusinessRuleException
{
long current = System.currentTimeMillis();
KnowledgeBase kbase = knowledgeBasesMap.get(rulesFileName);
if (kbase == null)
{
kbase = knowledgeBasesMap.get(rulesFileName + DRL);
}
if ((kbase == null) || ((current - lastRefreshedMilliseconds) >
refreshTimeMilliseconds))
{
if (rulesFileName.toLowerCase().indexOf(DRL) == -1)
{
kbase = load(rulesFileName + DRL);
}
else
{
kbase = load(rulesFileName);
}
lastRefreshedMilliseconds = System.currentTimeMillis();
}
this.assertionObject = assertionObject;
List assertionobjectslist = new ArrayList();
*// i am just doing this part just to make sure assertion object is not null
and i will get some answer. this part runs fine. *
if (assertionObject != null)
{
assertionobjectslist = assertionObject.getValidationObjects();
String StationNumber = ((BillingRecord)
assertionObject.get(0)).getStationNo();
System.out.println("Station Number in assertion object is " +
StationNumber);
}
else
{
System.out.println("Assertion Object is null");
}
System.out.println("The number of objects in assertionobject is " +
assertionobjectslist.size());
try
{
StatefulKnowledgeSession ksession =
kbase.newStatefulKnowledgeSession();
*//the next line throws the exception*
ksession.insert(assertionObject);
ksession.fireAllRules();
ksession.dispose();
}
catch (RuntimeDroolsException e1)
{
throw new BusinessRuleException(e1.getMessage());
}
businessRulesErrors = assertionObject.getBusinessRulesErrors();
if (throwException)
{
if (!assertionObject.getBusinessRulesErrors().isEmpty())
{
throw new BusinessRuleException(businessRulesErrors);
}
}
}
Any help is appreciated. thanks
17 years
- 3
- 2