Jason J [https://community.jboss.org/people/jasonjho] created the discussion "jBPM Persistence: Object unmarshalling with Drools accumulate" To view the discussion, visit: https://community.jboss.org/message/773261#773261 -------------------------------------------------------------- Environment: Drools 5.3.1 + jBPM5.2 I am using a custom ObjectMarshallingStrategy when using jBPM persistence b/c I am unable to serialize the Facts that are inserted into the working memory. To do this, I am plugging in a custom strategy on the persistence environment as such: env.set(EnvironmentName.OBJECT_MARSHALLING_STRATEGIES, new ObjectMarshallingStrategy[] {                 new MyResolverStrategy(...),                 new JPAPlaceholderResolverStrategy(persistenceEnv),                 new SerializablePlaceholderResolverStrategy(ClassObjectMarshallingStrategyAcceptor.DEFAULT)         }); I also have a rule in the ksession that is used to trigger some events in the jBPM workflow.  This rule uses the "collect" feature of Drools and it accumulates Facts until a condition is met. $currentApprovals: List(size >= 3) from collect(Approval() from $document.getCurrentApprovals()) I am getting the following exception java.io.OptionalDataException: null           at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1282) ~[na:1.6.0_31]           at java.io.ObjectInputStream.readObject(ObjectInputStream.java:350) ~[na:1.6.0_31]           at org.drools.marshalling.impl.InputMarshaller.readLeftTuple(InputMarshaller.java:714) ~[drools-core-5.3.1.Final-csi.jar:5.3.1.Final]           at org.drools.marshalling.impl.InputMarshaller.readLeftTuple(InputMarshaller.java:619) ~[drools-core-5.3.1.Final-csi.jar:5.3.1.Final]           at org.drools.marshalling.impl.InputMarshaller.readLeftTuples(InputMarshaller.java:584) ~[drools-core-5.3.1.Final-csi.jar:5.3.1.Final]           at org.drools.marshalling.impl.InputMarshaller.readFactHandles(InputMarshaller.java:433) ~[drools-core-5.3.1.Final-csi.jar:5.3.1.Final]           at org.drools.marshalling.impl.InputMarshaller.readSession(InputMarshaller.java:266) ~[drools-core-5.3.1.Final-csi.jar:5.3.1.Final]           at org.drools.marshalling.impl.InputMarshaller.readSession(InputMarshaller.java:196) ~[drools-core-5.3.1.Final-csi.jar:5.3.1.Final]           at org.drools.marshalling.impl.DefaultMarshaller.unmarshall(DefaultMarshaller.java:93) ~[drools-core-5.3.1.Final-csi.jar:5.3.1.Final]           at org.drools.persistence.SessionMarshallingHelper.loadSnapshot(SessionMarshallingHelper.java:91) ~[drools-jbpm-persistence-jpa-5.3.1.Final-csi.jar:5.3.1.Final]           ... 26 common frames omitted Looking at this code, I see case NodeTypeEnums.AccumulateNode: {                 // accumulate nodes generate new facts on-demand and need special procedures when de-serializing from persistent storage                 AccumulateMemory memory = (AccumulateMemory) context.wm.getNodeMemory( (BetaNode) sink );                 memory.betaMemory.getLeftTupleMemory().add( parentLeftTuple );                 readBehaviors( (BetaNode) sink,                                memory.betaMemory,                                context );                 AccumulateContext accctx = new AccumulateContext();                 parentLeftTuple.setObject( accctx );                 // first we de-serialize the generated fact handle                 InternalFactHandle handle = readFactHandle( context );                 accctx.result = new RightTuple( handle,                                                 (RightTupleSink) sink );                 // then we de-serialize the associated accumulation context                 accctx.context = (Serializable[]) stream.readObject(); ... ... It looks like the last line above is doing some deserializing.  I am not familiar with this lower level code, but shouldn't this be using the ObjectMarshallingStrategy?  How will the objects be able to deserialize correctly if I am relying on my own strategy to resolve facts? Any help would be appreciated!! -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/773261#773261] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]