October 2013 - rules-users - Jboss List Archives

NPE exception when retracting fact in Drools 5.5.0.Final and 5.3.0.Final

by Bransford-Koons, Geoff

I'm trying to update our application from Drools 4.0.7 to Drools 5.5 (or 5.3 if that's better). All the rules compile and I am serializing the KnowledgeBase and reading it in upon application start-up. Inserting facts works find. Retracting can often return the NullPointerException shown below. That clip comes from a unit test that literally just inserts 10 "TestFact" objects and then tries to retract them one at a time. No rule firing happens, just insertion and retraction. I did try adding a rule firing in between the insert and retraction loops but it made no difference. These "TestFact" object don't actually trigger any rules if that matters. I've tried this with both the Drools 5.5.0.Final and 5.3.0.Final jars with the same results. Searches on the forum and on Google show this as a bug in 5.5.0.Final, but say it should work in 5.3.0.Final. It doesn't work on either for me. I am going to try some variations on this test, but it seems like this should work as-is. Any suggestions would be greatly appreciated. 2013-10-14 11:56:02,533 (ERROR) [AgdKnowledgeSession] caught exception trying to retract TestFact [name=testfact-0] java.lang.NullPointerException at org.drools.core.util.RightTupleIndexHashTable.remove(RightTupleIndexHashTable.java:365) at org.drools.reteoo.NotNode.retractRightTuple(NotNode.java:172) at org.drools.reteoo.ObjectTypeNode.retractObject(ObjectTypeNode.java:257) at org.drools.reteoo.EntryPointNode.retractObject(EntryPointNode.java:330) at org.drools.common.NamedEntryPoint.retract(NamedEntryPoint.java:542) at org.drools.common.NamedEntryPoint.retract(NamedEntryPoint.java:486) at com.teradata.agd.AgdKnowledgeSession.retract(AgdKnowledgeSession.java:134) at com.teradata.agd.AgCoreManager.executeFactEvent(AgCoreManager.java:279) at com.teradata.agd.AgCoreManager.executeRuleEngine(AgCoreManager.java:189) at com.teradata.agd.AgCoreManager.enqueue(AgCoreManager.java:259) at com.teradata.agd.AgCoreManager.retractFact(AgCoreManager.java:480) at com.teradata.agdtest.functional.FactInsertionAndRetractionTest.testFactInsertion(FactInsertionAndRetractionTest.java:50) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:84) at org.testng.internal.Invoker.invokeMethod(Invoker.java:714) at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901) at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231) at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127) at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111) at org.testng.TestRunner.privateRun(TestRunner.java:767) at org.testng.TestRunner.run(TestRunner.java:617) at org.testng.SuiteRunner.runTest(SuiteRunner.java:335) at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:330) at org.testng.SuiteRunner.privateRun(SuiteRunner.java:291) at org.testng.SuiteRunner.run(SuiteRunner.java:240) at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52) at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86) at org.testng.TestNG.runSuitesSequentially(TestNG.java:1224) at org.testng.TestNG.runSuitesLocally(TestNG.java:1149) at org.testng.TestNG.run(TestNG.java:1057) at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:111) at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:204) at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:175)

12 years, 2 months

3
2
0 / 0

using eval(function(this))) in rule LHS

by Elran Dvir

Hi all, I have the a drl similar to the following drl: package com.checkpoint.correlation.impl.drools.package1; import java.util.Date import java.util.HashMap import com.checkpoint.correlation.impl.drools.Log import com.checkpoint.correlation.impl.drools.CorrelatedEvent global com.checkpoint.correlation.server.EventsHandler externalEventsHandler; function boolean filter(Log log) { return (log.fieldsMap.get("port")!= null && (!log.fieldsMap.get("product").toString().equals("-1"))); } function String calcSeverity(Log log) { return "High"; } declare Log @role( event) end declare CorrelatedEvent @role( event) @expires( 10s ) end // this rule will create a "Port Scan" event if none exist for this group-by values rule "Create Port Scan Event" dialect "java" no-loop when $log : Log(eval(filter(this))) accumulate(Log(eval(filter(this)) , this after[0s,5s] $log, fieldsMap.get("src") == $log.fieldsMap.get("src") , fieldsMap.get("dst") == $log.fieldsMap.get("dst"), $port : fieldsMap.get("port")); $portSet : collectSet($port); $portSet.size > 2 ) accumulate( CpLog(eval(filter(this)), this after[0s,5s] $log, fieldsMap.get("src") == $log.fieldsMap.get("src") , fieldsMap.get("dst") == $log.fieldsMap.get("dst"), $portSet.contains(fieldsMap.get("port")), $marker : fieldsMap.get("marker")); $markerSet : collectSet($marker)) not CorrelatedEvent(getId() == "portScan" , groupByFieldsMap.get("src") == $log.fieldsMap.get("src") , groupByFieldsMap.get("dst") == $log.fieldsMap.get("dst")) then System.out.println("port scan"); System.out.println(drools.getRule().getId()); CorrelatedEvent $ce = new CorrelatedEvent("portScan"); $ce.groupByFieldsMap.put("src", $log.fieldsMap.get("src")); $ce.groupByFieldsMap.put("dst", $log.fieldsMap.get("dst")); insert($ce); HashMap<String,Object> fieldsMap = new HashMap<String,Object>(); fieldsMap.put("src",$log.fieldsMap.get("src")); fieldsMap.put("dst",$log.fieldsMap.get("dst")); fieldsMap.put("cu_rule_severity", calcSeverity($log)); fieldsMap.put("markers",$markerSet.toString()); externalEventsHandler.handleEvent(fieldsMap); end when I compile it, I am getting the error "Cannot use this in a static context". This is because the use of filter(this). I know that in this example, I can write my conditions inside the fact, but I have more complicated cases, so I prefer to use a function. So, how can I use a function with the fact being processed? Thanks!

12 years, 3 months

2
1
0 / 0

Ask about Drools, Business Rule (.brl file) and technical rule (.drl)

by Trong Hieu Tran

Hello Madam/ Sir I'm Trong-Hieu, I'm developer at Clearpath LLC. I'm stuck with drools guvnor and realy need your help please. We developed web application with drools rules - technical rules (.drl). Our project has a large of technical rule, one nice day, the customer would like to transfer all the technical rules to business rules (.brl files). I have searched on internet and can not find the right way to do. Please help! If you have any documents or reference links please show me. I heard about Drools guvnor 6 that it allows the user use Guide Editor to edit technical rule file (.drl), so if it is true, could I transform business rule to technical rule in drools 6? Please help me, I'm sorry to take your time. Thank you, Trong Hieu

12 years, 3 months

2
2
0 / 0

classloader issues

by Kiru Pakkirisamy

Hi all, I am able to run the sample in Eclipse. But when I try to run it in my server, I get classloader issues. Basically, I am trying to use Drools inside HBase coprocessor code. The coprocessor code is loaded from a jar on hdfs. But the rules engine does not seem to be able to use its parent classloader to load the classes it needs.Instead if I put my code on a jar file and put it in the server classpath it works "ok" but still not good, as the class Drools wants is loaded by two different classloaders (one from hdfs) and the other one is using the jar files in the classpath of Hbase. Do I have add any other dir name so that the generated code classes can be picked up as well. I am using .5.5 final. Regards, - kiru Kiru Pakkirisamy | webcloudtech.wordpress.com

12 years, 3 months

1
0
0 / 0

Please help me on hibernate-meet-drools

by Hong Ju

Hi, I would like Drools to save my POJO objects as Hibernate Entities so that I can see my POJO objects as db tables in my database. I tried to make this work by searching on the net, but there is very limited example on this topic, my code does not have any error, but it does not save any tables in my db. I attached my project in this email, if someone can help me on this, this will be so great and make me move forward. Thank you so much in advance, Hong Lily Ju Software Engineer hong.ju(a)steward.org<mailto:derrick.smith@steward.org> Steward Heath Care [Description: cid:image001.png@01CD0DC1.C0D81BD0] Office: 781-375-3034 Cell: 781-801-9313

12 years, 3 months

2
1
0 / 0

Drools Flow

by vojedav

What happened with that project? Is embedded in Rules Expert o where? If I want to develop an app with workflow, have I to get jBPM instead? Thanks in advance -- View this message in context: http://drools.46999.n3.nabble.com/Drools-Flow-tp4026363.html Sent from the Drools: User forum mailing list archive at Nabble.com.

12 years, 3 months

2
1
0 / 0

Pattern of usage question

by Laird Nelson

I have several questions about using Drools in a stateless Java EE application. (I've actually used it for years, but have always felt an impedance mismatch and finally have a moment to ask about it. :-)) Like (I suspect) many people, I have a stateless session bean responsible for some business logic with Drools in the mix. I'm looking to implement its—say—doWork() method with a knowledge session under the covers. What I'm curious about is: in a rules engine, facts are sort of expected to stick around for a while (that's state; I know there are stateless sessions, but those are kind of ephemeral). You grab a bunch of facts, and over time they get inserted into the knowledge session, which sticks around in some manner. Then, periodically, you fire all rules, and deal with the consequences. Along comes another processing situation; you fire all rules, and deal with the consequences again. And so on. The fact maintenance seems stateful here while the rule processing is stateless. How do people deploy stateless systems with this stateful concept at their core? Which of the many possibilities is most commonly used? Serialize/deserialize the session on each request (yuck)? Singleton beans (yuck, I think)? Outboard drools server with RPC (also yuck, I think)? Next, in a dynamic business application, it's often the case that single rules need to be added to the knowledge base. Someone wants to add in, for example, a new way of calculating fees. They don't—at a human level—want to open up the catalog of 47,000 rules, add one, and then re-install/re-deploy the thus-changed catalog of rules. They just—again, at a human level—want to add a new rule. Is redeploying the catalog the only way to go here, or is there a way that I've missed to incrementally and programmatically add a rule to a KnowledgeBase? More generally: in a stateless app, where do these concepts live? Where do they *best* live, I should say? (For completeness, I'm the author of the drools-jca<https://code.google.com/p/drools-jca/>project, which attempts to make Drools 5.x Java EE compatible by offloading its filesystem and threading operations into a JCA resource adapter. I'm not convinced that's the best place for it and with Drools 6 doing different things with threads and with Java EE 7 relaxing its restrictions on filesystem access I'm looking for better patterns.) Thanks very much for reading; looking forward to the replies. Best, Laird -- http://about.me/lairdnelson

12 years, 3 months

2
1
0 / 0

Are rule templates part of supported API?

by darrell.pittman

I am new to drools. The drools API doesn't include the ExternalSpreadSheetCompiler. The on-line user guide (section 2.4.7 in the expert guide) has an incorrect example for how to load a rule template and data spreadsheet. It just shows loading the spreadsheet. No mention of loading the rule template. My question is: Is the ExternalSpreadSheetCompiler the correct way to load in a rule template that uses a spreadsheet for it's data source? Note: Eclipse gives a "Discouraged Access" warning when using the ExternalSpreadSheetCompiler. -- View this message in context: http://drools.46999.n3.nabble.com/Are-rule-templates-part-of-supported-AP... Sent from the Drools: User forum mailing list archive at Nabble.com.

12 years, 3 months

2
1
0 / 0

Dynamically populate Rule-Flow Group?

by nzhu972

Hi, I am using BRMS 5.3.1 and I have a scenario where I will have multiple decision tables and for each decision table, a corresponding workflow process is associated with it (scenario 1) Scenario 1. decision table: X, Y, Z WorkFlow : A, B, C Since there are no difference between the workflows except for the decision table that the flow is referencing, I like to combine the workflows into one single flow and dynamically populate the rule-flow group (see scenario 2) Scenario 2. decision table: X, Y, Z WorkFlow : A The rule-flow group will determine which set of decision table is relevant. I have not seen examples where rule-flow group or any other attribute being dynamically populated. Typically, they are assigned with a string during declaration. My question is : is it possible to dynamic determine the value for rule-flow group during run time and then assign it with a value? Thanks in advance for any advice. -- View this message in context: http://drools.46999.n3.nabble.com/Dynamically-populate-Rule-Flow-Group-tp... Sent from the Drools: User forum mailing list archive at Nabble.com.

12 years, 3 months

1
0
0 / 0

use a boolean returned type function in "when", doesn't work, why?

by merry0900

my drl file like this： import ******** function boolean isNotNull(String a){ if(a!=null){ return true;} return false; }. rule a when isNotNull("aaaa"); then // mycode end how i could use like this， thank you all -- View this message in context: http://drools.46999.n3.nabble.com/use-a-boolean-returned-type-function-in... Sent from the Drools: User forum mailing list archive at Nabble.com.

12 years, 3 months

4
4
0 / 0

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

rules-users October 2013