[rules-dev] Expression Timer NPE Drools 6.0.1.Final
Roger Lefebvre
roger at precipicetech.com
Tue May 13 11:45:40 EDT 2014
As suggested, I wrote some tests based on methods defined in the given
class. That is, I extend from CommonTestMethodBase and used
"loadKnowledgeBaseFromString(str)" to define the base for my KieSession. I
was unable to reproduce the exception. I went through several cycles
altering initializations, stripping down the rule, so forth but still to no
avail.
Some of the steps I followed:
- Eliminate test harness. I added a main in my test class and simply
instantiated that class and called the method directly.
- Executed in different environment. Changed from Intellij Idea IDE, to
Eclipse IDE. Have not tried command line.
- In my application, I create the declared class externally and inject it
into the engine The test method, on the other hand, injects the declared
class via a high salience "init" rule. As such, I tried same approach in my
application.
- In my application, removed all other rules, global, unused declarations.
Further, I pruned down the offending rule to rudimentary instructions.
I have yet to dive into the drools/kie code to identify the differences, if
any, between the test and application engine and rule initialization paths.
Before I do, are there any suggestions on what other route I might take?
Thank you,
Roger
On Sat, May 10, 2014 at 11:06 AM, Mark Proctor <mproctor at codehaus.org>wrote:
> We have a number of unit tests for expressions:
>
> https://github.com/droolsjbpm/drools/blob/master/drools-compiler/src/test/java/org/drools/compiler/integrationtests/TimerAndCalendarTest.java
>
> Could you add a unit test to demonstrate your problem, and submit it as a
> pull request?
>
> http://docs.jboss.org/drools/release/5.5.0.Final/droolsjbpm-introduction-docs/html/gettingstarted.html
>
> Mark
> On 7 May 2014, at 21:36, rogerL <roger at precipicetech.com> wrote:
>
> > Hello,
> >
> > I'm encountering an NPE when attempting to use and expression timer in my
> > rule.
> > env:
> > Drools 6.0.1.Final
> > OS Maverick
> > IDE Intellij Idea
> > Java 7
> >
> > Given the ebb and flow nature of the facts in the system, we want to be
> able
> > to control the cycles dynamically. Hence the desire to use the expression
> > timer.
> > The expression that I tried is based on the 6.0.1 documentation.
> > That is, something of the form *Timer(expr: $d, $p)*
> > In an effort to get beyond the NPE, I tried playing around with the
> > parameters by using combinations of both longs and appropriately
> formatted
> > strings (e.g. 10s, 1m, etc), and using only the delay.
> > I saw mention that a semicolon should follow the expression. That equally
> > failed.
> > The interval and cron timer variations, however, both work.
> >
> >
> > The .drl and exception are:
> >
> > declare SystemControlData
> > isEnabled : boolean = false
> > delay : long = 30
> > period : long = 60000
> > maxCallQueueDepth : int = 1
> > end
> >
> >
> > rule "If the system is enabled start campaign check at specified
> interval"
> > agenda-group "system_criteria"
> > // auto-focus true
> > salience 20
> > // timer( expr: $d, $p ) throws NPE
> > // timer( expr: $d; ) throws NPE
> > timer(cron:0/5 * * * * ?)
> > when
> > SystemControlData(isEnabled==true, $d: delay, $p:period,
> > maxCallQueueDepth>0)
> > then
> > drools.setFocus( "campaign_criteria" );
> > end
> >
> >
> >
> > Exception in thread "SimpleAsyncTaskExecutor-1"
> > java.lang.NullPointerException
> > at
> >
> org.drools.core.base.mvel.MVELCompilationUnit.createFactory(MVELCompilationUnit.java:262)
> > at
> >
> org.drools.core.base.mvel.MVELCompilationUnit.getFactory(MVELCompilationUnit.java:276)
> > at
> >
> org.drools.core.base.mvel.MVELObjectExpression.getValue(MVELObjectExpression.java:76)
> > at
> org.drools.core.time.TimeUtils.evalTimeExpression(TimeUtils.java:140)
> > at
> >
> org.drools.core.time.impl.ExpressionIntervalTimer.createTrigger(ExpressionIntervalTimer.java:151)
> > at
> >
> org.drools.core.phreak.PhreakTimerNode.createTrigger(PhreakTimerNode.java:260)
> > at
> >
> org.drools.core.phreak.PhreakTimerNode.scheduleLeftTuple(PhreakTimerNode.java:230)
> > at
> >
> org.drools.core.phreak.PhreakTimerNode.doLeftInserts(PhreakTimerNode.java:93)
> > at
> org.drools.core.phreak.PhreakTimerNode.doNode(PhreakTimerNode.java:69)
> > at
> >
> org.drools.core.phreak.RuleNetworkEvaluator.innerEval(RuleNetworkEvaluator.java:357)
> > at
> >
> org.drools.core.phreak.RuleNetworkEvaluator.outerEval(RuleNetworkEvaluator.java:161)
> > at
> >
> org.drools.core.phreak.RuleNetworkEvaluator.evaluateNetwork(RuleNetworkEvaluator.java:116)
> > at
> >
> org.drools.core.phreak.RuleExecutor.reEvaluateNetwork(RuleExecutor.java:200)
> > at
> >
> org.drools.core.phreak.RuleExecutor.evaluateNetworkAndFire(RuleExecutor.java:67)
> > at
> > org.drools.core.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:935)
> > at
> >
> org.drools.core.common.DefaultAgenda.fireUntilHalt(DefaultAgenda.java:1160)
> > at
> >
> org.drools.core.common.AbstractWorkingMemory.fireUntilHalt(AbstractWorkingMemory.java:1002)
> > at
> >
> org.drools.core.common.AbstractWorkingMemory.fireUntilHalt(AbstractWorkingMemory.java:978)
> > at
> >
> org.drools.core.impl.StatefulKnowledgeSessionImpl.fireUntilHalt(StatefulKnowledgeSessionImpl.java:273)
> >
> >
> >
> > --
> > View this message in context:
> http://drools.46999.n3.nabble.com/Expression-Timer-NPE-Drools-6-0-1-Final-tp4029469.html
> > Sent from the Drools: Developer (committer) mailing list mailing list
> archive at Nabble.com.
> > _______________________________________________
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>
>
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--
Roger Lefebvre
President, Precipice Technologies Inc.
(e) roger at precipicetech.com
(c) 403 466 2622
(f) 403 475 0566
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