Re: [rules-users] Strange property access behavior resulting in NullPointerException

I am using Drools 4.0.3. I have a rule that I believe should work but causes a NullPointerException at runtime. The rule phrased this way causes a NullPointerException: rule "Create Order Limit" when CandleSeries( $instrument : instrumentSpecification ) then insert(new OrderConstraint( $instrument )); end While the same rule phased like this works fine: rule "Create Order Limit" when $candle : CandleSeries( ) then insert(new OrderConstraint( $candle.getInstrumentSpecification() )); end Is this right? I was looking at rule example 10.27 in the Drools guide and it's written exactly like rule #1 is. Here is the full stack trace of the rule execution from version 1: java.lang.NullPointerException at org.activequant.core.domainmodel.TimeSeries.getInstrumentSpecification(Unknown Source) at org.drools.base.org.activequant.core.domainmodel.CandleSeries2216507$getInstrumentSpecification.getValue(Unknown Source) at org.drools.base.ClassFieldExtractor.getValue( ClassFieldExtractor.java:127) at org.drools.rule.Declaration.getValue(Declaration.java:197) at sequitem.quanteq.ruleflow.Rule_Create_Order_Limit_0ConsequenceInvoker.evaluate (Rule_Create_Order_Limit_0ConsequenceInvoker.java:17) at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java :550) at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java :514) at org.drools.common.AbstractWorkingMemory.fireAllRules( AbstractWorkingMemory.java:462) at org.drools.common.AbstractWorkingMemory.fireAllRules( AbstractWorkingMemory.java:424) at sequitem.quanteq.rules.engine.StatefulEngine.execute( StatefulEngine.java:50) at sequitem.quanteq.rules.engine.StatefulEngine.execute( StatefulEngine.java:24) at sequitem.quanteq.rules.RandomMarketEntryRulesTest.testRandomMarketEntryRules (RandomMarketEntryRulesTest.java:55) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke( NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke( DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at junit.framework.TestCase.runTest(TestCase.java:168) at junit.framework.TestCase.runBare(TestCase.java:134) at junit.framework.TestResult$1.protect(TestResult.java:110) at junit.framework.TestResult.runProtected(TestResult.java:128) at junit.framework.TestResult.run(TestResult.java:113) at junit.framework.TestCase.run(TestCase.java:124) at junit.framework.TestSuite.runTest(TestSuite.java:232) at junit.framework.TestSuite.run(TestSuite.java:227) at junit.textui.TestRunner.doRun(TestRunner.java:116) at junit.textui.TestRunner.doRun(TestRunner.java:109) at junit.textui.TestRunner.run(TestRunner.java:77) at junit.textui.TestRunner.run(TestRunner.java:62) at sequitem.quanteq.rules.RandomMarketEntryRulesTest.main( RandomMarketEntryRulesTest.java:63) E Time: 36.687 There was 1 error: 1) testRandomMarketEntryRules( sequitem.quanteq.rules.RandomMarketEntryRulesTest)org.drools.spi.ConsequenceException: java.lang.NullPointerException at org.drools.base.DefaultConsequenceExceptionHandler.handleException( DefaultConsequenceExceptionHandler.java:14) at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java :553) at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java :514) at org.drools.common.AbstractWorkingMemory.fireAllRules( AbstractWorkingMemory.java:462) at org.drools.common.AbstractWorkingMemory.fireAllRules( AbstractWorkingMemory.java:424) at sequitem.quanteq.rules.engine.StatefulEngine.execute( StatefulEngine.java:50) at sequitem.quanteq.rules.engine.StatefulEngine.execute( StatefulEngine.java:24) at sequitem.quanteq.rules.RandomMarketEntryRulesTest.testRandomMarketEntryRules (RandomMarketEntryRulesTest.java:55) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke( NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke( DelegatingMethodAccessorImpl.java:25) at sequitem.quanteq.rules.RandomMarketEntryRulesTest.main( RandomMarketEntryRulesTest.java:63) Caused by: java.lang.NullPointerException at org.activequant.core.domainmodel.TimeSeries.getInstrumentSpecification(Unknown Source) at org.drools.base.org.activequant.core.domainmodel.CandleSeries2216507$getInstrumentSpecification.getValue(Unknown Source) at org.drools.base.ClassFieldExtractor.getValue( ClassFieldExtractor.java:127) at org.drools.rule.Declaration.getValue(Declaration.java:197) at sequitem.quanteq.ruleflow.Rule_Create_Order_Limit_0ConsequenceInvoker.evaluate (Rule_Create_Order_Limit_0ConsequenceInvoker.java:17) at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java :550) ... 23 more _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users