[rules-users] Collect CE requires a non-argument Exception..

[techy]

I'm getting following exception when tried to insert an object(which has a
Long field and three List reference) retrieved from dao in rule conseqence.
>From stackTrace, I can see that it is thrown when drools is trying to create
an instance of List(which is not possible).

Please someone clarify this. Thanks in advance.

org.drools.spi.ConsequenceException: org.drools.RuntimeDroolsException:
Collect CE requires a non-argument constructor for the return type
	at
org.drools.base.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:13)
	at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:558)
	at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:518)
Caused by: org.drools.RuntimeDroolsException: Collect CE requires a
non-argument constructor for the return type
	at org.drools.rule.Collect.instantiateResultObject(Collect.java:69)
	at org.drools.reteoo.CollectNode.assertTuple(CollectNode.java:111)
	at
org.drools.reteoo.CompositeTupleSinkAdapter.propagateAssertTuple(CompositeTupleSinkAdapter.java:30)
	at org.drools.reteoo.JoinNode.assertObject(JoinNode.java:156)
	at
org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:318)
	at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:162)
	at org.drools.reteoo.Rete.assertObject(Rete.java:175)
	at org.drools.reteoo.ReteooRuleBase.assertObject(ReteooRuleBase.java:192)
	at
org.drools.reteoo.ReteooWorkingMemory.doInsert(ReteooWorkingMemory.java:71)
	at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:911)
	at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:883)
	at
org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:67)
	at
org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:61)
	at
Caused by: java.lang.InstantiationException: java.util.List
	at java.lang.Class.newInstance0(Unknown Source)
	at java.lang.Class.newInstance(Unknown Source)
	at org.drools.rule.Collect.instantiateResultObject(Collect.java:64)
	... 27 more
-- 
View this message in context: http://www.nabble.com/Collect-CE-requires-a-non-argument-Exception..-tp20985282p20985282.html
Sent from the drools - user mailing list archive at Nabble.com.