2:45 p.m.
Using org.drools.verifier found in "drools-verifier-5.1.1.jar" I get an
org.drools.RuntimeDroolsException if a pattern in a rule LHS contains a
comparison to a literal value using the equals operator.
Please consider the following rule I created solely for the purposes of
isolating this issue.
package com.simple.test.rule
import com.p1s.mps.rulevalidator.TestFact;
rule "TestRule"
when
$fact : TestFact(value == 1)
then
System.out.println($fact.getValue());
end
The following class definition for the TestFact.
package com.p1s.mps.rulevalidator;
public class TestFact
{
private int value;
public TestFact(int value) {
this.value = value;
}
public int getValue() {
return value;
}
public void setValue(int value) {
this.value = value;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + value;
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
TestFact other = (TestFact) obj;
if (value != other.value)
return false;
return true;
}
}
The following unit test which attempts to use Verifier.
@Test
public final void testVerifierOnLiteral()
{
VerifierBuilder verBuilder =
VerifierBuilderFactory.newVerifierBuilder();
Verifier ver = verBuilder.newVerifier();
String ruleText = getRuleFromResource(TEST_RULE);
ver.addResourcesToVerify( ResourceFactory.newReaderResource(
new StringReader( ruleText ) ), ResourceType.DRL );
Assert.assertTrue(ver.fireAnalysis());
}
Running the test with JUnit produces the following exception.
java.lang.RuntimeException: org.drools.RuntimeDroolsException: Exception
executing ReturnValue constraint
org.drools.rule.ReturnValueRestriction@589f81 : [Error: cannot convert
<1> to a numeric type: class java.lang.Integer [0]]
[Near : {... Unknown ....}]
^
[Line: 1, Column: 0]
at
org.drools.verifier.builder.VerifierImpl.analyse(VerifierImpl.java:148)
at
org.drools.verifier.builder.VerifierImpl.fireAnalysis(VerifierImpl.java:
117)
at
com.p1s.mps.rulevalidator.NumericConversionTest.testVerifierOnLiteral(Nu
mericConversionTest.java:64)
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.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMet
hod.java:44)
at
org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallab
le.java:15)
at
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMetho
d.java:41)
at
org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod
.java:20)
at
org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.jav
a:28)
at
org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:
31)
at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner
.java:73)
at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner
.java:46)
at
org.junit.runners.ParentRunner.runChildren(ParentRunner.java:180)
at
org.junit.runners.ParentRunner.access$000(ParentRunner.java:41)
at
org.junit.runners.ParentRunner$1.evaluate(ParentRunner.java:173)
at
org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.jav
a:28)
at
org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:
31)
at
org.junit.runners.ParentRunner.run(ParentRunner.java:220)
at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4Tes
tReference.java:46)
at
org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.ja
va:38)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTe
stRunner.java:467)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTe
stRunner.java:683)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRun
ner.java:390)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRu
nner.java:197)
Caused by: org.drools.RuntimeDroolsException: Exception executing
ReturnValue constraint org.drools.rule.ReturnValueRestriction@589f81 :
[Error: cannot convert <1> to a numeric type: class java.lang.Integer
[0]]
[Near : {... Unknown ....}]
^
[Line: 1, Column: 0]
at
org.drools.rule.ReturnValueConstraint.isAllowedCachedRight(ReturnValueCo
nstraint.java:168)
at
org.drools.common.TripleBetaConstraints.isAllowedCachedRight(TripleBetaC
onstraints.java:211)
at
org.drools.reteoo.NotNode.assertObject(NotNode.java:140)
at
org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleOb
jectSinkAdapter.java:59)
at
org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:145)
at
org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(Com
positeObjectSinkAdapter.java:450)
at
org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(Compo
siteObjectSinkAdapter.java:378)
at
org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:190)
at
org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:145)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.jav
a:1174)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.jav
a:1123)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.jav
a:917)
at
org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSes
sionImpl.java:251)
at
org.drools.verifier.builder.VerifierImpl.analyse(VerifierImpl.java:136)
... 26 more
Caused by: org.drools.RuntimeDroolsException: [Error: cannot convert <1>
to a numeric type: class java.lang.Integer [0]]
[Near : {... Unknown ....}]
^
[Line: 1, Column: 0]
at
org.drools.rule.ReturnValueRestriction.isAllowed(ReturnValueRestriction.
java:236)
at
org.drools.rule.ReturnValueConstraint.isAllowedCachedRight(ReturnValueCo
nstraint.java:162)
... 39 more
Caused by: [Error: cannot convert <1> to a numeric type: class
java.lang.Integer [0]]
[Near : {... Unknown ....}]
^
[Line: 1, Column: 0]
at
org.mvel2.math.MathProcessor.getInternalNumberFromType(MathProcessor.jav
a:577)
at
org.mvel2.math.MathProcessor._doOperations(MathProcessor.java:155)
at
org.mvel2.math.MathProcessor.doOperations(MathProcessor.java:79)
at
org.mvel2.ast.BinaryOperation.getReducedValueAccelerated(BinaryOperation
.java:102)
at org.mvel2.MVELRuntime.execute(MVELRuntime.java:85)
at
org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:1
04)
at org.mvel2.MVEL.executeExpression(MVEL.java:978)
at
org.drools.base.mvel.MVELReturnValueExpression.evaluate(MVELReturnValueE
xpression.java:92)
at
org.drools.rule.ReturnValueRestriction.isAllowed(ReturnValueRestriction.
java:226)
... 40 more
However, if I use the following version of the same rule where I have
added parentheses it works.
package com.simple.test.rule
import com.p1s.mps.rulevalidator.TestFact;
rule "TestRule"
when
$fact : TestFact(value == (1))
then
System.out.println($fact.getValue());
end
Note that both versions of the DRL file compile, run, and produce the
correct results.
Thank You,
Nathan Bell