SerializationException when storing ScheduleToken in a Saga using JacksonSerializer

The EventScheduler interface returns a ScheduleToken type as a return to schedule(). The problem is when a Saga is beign loaded, the token cannot be deserialized cause ScheduleToken is an abstract class.

Possible solutions are:

• enable default typing on jackson (personally i don’t like this one)
• provide JsonTypeInfo on ScheduleToken
• implement a mechanism to provide own serializer/deserializer for ScheduleToken (possibly using previous approach as a default)

Below is a stack trace of an error.

org.axonframework.serialization.SerializationException: Error while deserializing object
	at org.axonframework.serialization.json.JacksonSerializer.deserialize(JacksonSerializer.java:214) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.saga.repository.jpa.JpaSagaStore.loadSaga(JpaSagaStore.java:150) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.saga.repository.AnnotatedSagaRepository.doLoadSaga(AnnotatedSagaRepository.java:251) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.saga.repository.AnnotatedSagaRepository.lambda$doLoad$1(AnnotatedSagaRepository.java:131) ~[axon-core-3.2.1.jar:3.2.1]
	at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660) ~[na:1.8.0_144]
	at org.axonframework.eventhandling.saga.repository.AnnotatedSagaRepository.doLoad(AnnotatedSagaRepository.java:130) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.saga.repository.AnnotatedSagaRepository.doLoad(AnnotatedSagaRepository.java:46) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.saga.repository.LockingSagaRepository.load(LockingSagaRepository.java:54) ~[axon-core-3.2.1.jar:3.2.1]
	at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) ~[na:1.8.0_144]
	at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175) ~[na:1.8.0_144]
	at java.util.TreeMap$KeySpliterator.forEachRemaining(TreeMap.java:2746) ~[na:1.8.0_144]
	at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580) ~[na:1.8.0_144]
	at java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:270) ~[na:1.8.0_144]
	at java.util.HashMap$KeySpliterator.forEachRemaining(HashMap.java:1548) ~[na:1.8.0_144]
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481) ~[na:1.8.0_144]
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) ~[na:1.8.0_144]
	at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708) ~[na:1.8.0_144]
	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:1.8.0_144]
	at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499) ~[na:1.8.0_144]
	at org.axonframework.eventhandling.saga.AbstractSagaManager.handle(AbstractSagaManager.java:70) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.AbstractEventProcessor.lambda$null$2(AbstractEventProcessor.java:139) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.messaging.DefaultInterceptorChain.proceed(DefaultInterceptorChain.java:57) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.messaging.interceptors.CorrelationDataInterceptor.handle(CorrelationDataInterceptor.java:65) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.messaging.DefaultInterceptorChain.proceed(DefaultInterceptorChain.java:55) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.TrackingEventProcessor.lambda$new$1(TrackingEventProcessor.java:176) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.messaging.DefaultInterceptorChain.proceed(DefaultInterceptorChain.java:55) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.messaging.interceptors.TransactionManagingInterceptor.handle(TransactionManagingInterceptor.java:50) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.messaging.DefaultInterceptorChain.proceed(DefaultInterceptorChain.java:55) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.AbstractEventProcessor.lambda$processInUnitOfWork$3(AbstractEventProcessor.java:146) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.messaging.unitofwork.BatchingUnitOfWork.executeWithResult(BatchingUnitOfWork.java:80) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.AbstractEventProcessor.processInUnitOfWork(AbstractEventProcessor.java:135) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.TrackingEventProcessor.processBatch(TrackingEventProcessor.java:282) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.TrackingEventProcessor.processingLoop(TrackingEventProcessor.java:209) ~[axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.TrackingEventProcessor$TrackingSegmentWorker.run(TrackingEventProcessor.java:620) [axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.TrackingEventProcessor$WorkerLauncher.run(TrackingEventProcessor.java:713) [axon-core-3.2.1.jar:3.2.1]
	at org.axonframework.eventhandling.TrackingEventProcessor$CountingRunnable.run(TrackingEventProcessor.java:547) [axon-core-3.2.1.jar:3.2.1]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_144]
Caused by: com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `org.axonframework.eventhandling.scheduling.ScheduleToken` (no Creators, like default construct, exist): abstract types either need to be mapped to concrete types, have custom deserializer, or contain additional type information
 at [Source: (byte[])"..."; line: 1, column: 176] (through reference chain: custis.modeus.notification.component.notification.command.saga.PersonNotificationPublishingSaga["retryToken"])
	at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:67) ~[jackson-databind-2.9.3.jar:2.9.3]
	at com.fasterxml.jackson.databind.DeserializationContext.reportBadDefinition(DeserializationContext.java:1451) ~[jackson-databind-2.9.3.jar:2.9.3]
	at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1027) ~[jackson-databind-2.9.3.jar:2.9.3]
	at com.fasterxml.jackson.databind.deser.AbstractDeserializer.deserialize(AbstractDeserializer.java:265) ~[jackson-databind-2.9.3.jar:2.9.3]
	at com.fasterxml.jackson.databind.deser.impl.FieldProperty.deserializeAndSet(FieldProperty.java:136) ~[jackson-databind-2.9.3.jar:2.9.3]
	at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:287) ~[jackson-databind-2.9.3.jar:2.9.3]
	at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:151) ~[jackson-databind-2.9.3.jar:2.9.3]
	at com.fasterxml.jackson.databind.ObjectReader._bindAndClose(ObjectReader.java:1611) ~[jackson-databind-2.9.3.jar:2.9.3]
	at com.fasterxml.jackson.databind.ObjectReader.readValue(ObjectReader.java:1234) ~[jackson-databind-2.9.3.jar:2.9.3]
	at org.axonframework.serialization.json.JacksonSerializer.deserialize(JacksonSerializer.java:212) ~[axon-core-3.2.1.jar:3.2.1]

[smcvb]

I follow your example @m1l4n54v1c, but serializing the token to Jackson is what’s currently not working, or only if you’ve introduced a solution like @vogoltsov shared with us. Thus the changes are pretty slim that adding the @JsonTypeInfo would case lots of backward compatibility issues, other than for @vogoltsov (sorry for that).

I’d assume that adding the type info is the simplest approach for now with I assume little impact for our users. Hope I’m right there 😉

[smcvb]

Resolved this issue in #598