Error in saving an entity that has a HashSet field when the @EnableReactiveMongoAuditing annotation is active.

[mahdibohloul]

I have defined a Kotlin class that contains a field such as Map<Enum, HashSet<Something>> and I can save it in the database. Now when I use the @EnableReactiveMongoAuditing annotation, I encounter the following error:

java.lang.reflect.InaccessibleObjectException: Unable to make field private transient java.util.HashMap java.util.HashSet.map accessible: module java.base does not "opens java.util" to unnamed module @661972b0
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:354) ~[na:na]
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297) ~[na:na]
	at java.base/java.lang.reflect.Field.checkCanSetAccessible(Field.java:178) ~[na:na]
	at java.base/java.lang.reflect.Field.setAccessible(Field.java:172) ~[na:na]
	at org.springframework.util.ReflectionUtils.makeAccessible(ReflectionUtils.java:804) ~[spring-core-6.1.4.jar:6.1.4]
	at org.springframework.data.mapping.context.AbstractMappingContext$PersistentPropertyCreator.doWith(AbstractMappingContext.java:540) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.util.ReflectionUtils.doWithFields(ReflectionUtils.java:728) ~[spring-core-6.1.4.jar:6.1.4]
	at org.springframework.data.mapping.context.AbstractMappingContext.doAddPersistentEntity(AbstractMappingContext.java:426) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.AbstractMappingContext.addPersistentEntity(AbstractMappingContext.java:383) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:279) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:293) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mongodb.core.mapping.MongoMappingContext.getPersistentEntity(MongoMappingContext.java:132) ~[spring-data-mongodb-4.2.3.jar:4.2.3]
	at org.springframework.data.mongodb.core.mapping.MongoMappingContext.getPersistentEntity(MongoMappingContext.java:41) ~[spring-data-mongodb-4.2.3.jar:4.2.3]
	at org.springframework.data.mapping.context.MappingContext.getRequiredPersistentEntity(MappingContext.java:147) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.lambda$from$2(PersistentPropertyPathFactory.java:259) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.model.BasicPersistentEntity.doWithProperties(BasicPersistentEntity.java:298) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.from(PersistentPropertyPathFactory.java:264) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.lambda$from$2(PersistentPropertyPathFactory.java:260) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.model.BasicPersistentEntity.doWithProperties(BasicPersistentEntity.java:298) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.from(PersistentPropertyPathFactory.java:264) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.from(PersistentPropertyPathFactory.java:235) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.from(PersistentPropertyPathFactory.java:166) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.AbstractMappingContext.doFindPersistentPropertyPaths(AbstractMappingContext.java:333) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.AbstractMappingContext.findPersistentPropertyPaths(AbstractMappingContext.java:317) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.auditing.MappingAuditableBeanWrapperFactory$MappingAuditingMetadata.findPropertyPaths(MappingAuditableBeanWrapperFactory.java:150) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.auditing.MappingAuditableBeanWrapperFactory$MappingAuditingMetadata.<init>(MappingAuditableBeanWrapperFactory.java:124) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.auditing.MappingAuditableBeanWrapperFactory.lambda$getBeanWrapperFor$0(MappingAuditableBeanWrapperFactory.java:85) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at java.base/java.util.concurrent.ConcurrentMap.computeIfAbsent(ConcurrentMap.java:330) ~[na:na]
	at org.springframework.data.auditing.MappingAuditableBeanWrapperFactory.lambda$getBeanWrapperFor$1(MappingAuditableBeanWrapperFactory.java:84) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.context.PersistentEntities.lambda$mapOnContext$2(PersistentEntities.java:144) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179) ~[na:na]
	at java.base/java.util.Spliterators$ArraySpliterator.tryAdvance(Spliterators.java:1002) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:129) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:527) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:513) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:150) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:647) ~[na:na]
	at org.springframework.data.mapping.context.PersistentEntities.mapOnContext(PersistentEntities.java:145) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.auditing.MappingAuditableBeanWrapperFactory.lambda$getBeanWrapperFor$3(MappingAuditableBeanWrapperFactory.java:82) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at java.base/java.util.Optional.flatMap(Optional.java:289) ~[na:na]
	at org.springframework.data.auditing.MappingAuditableBeanWrapperFactory.getBeanWrapperFor(MappingAuditableBeanWrapperFactory.java:76) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.auditing.AuditingHandlerSupport.isAuditable(AuditingHandlerSupport.java:101) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.auditing.ReactiveIsNewAwareAuditingHandler.markAudited(ReactiveIsNewAwareAuditingHandler.java:71) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mongodb.core.mapping.event.ReactiveAuditingEntityCallback.onBeforeConvert(ReactiveAuditingEntityCallback.java:52) ~[spring-data-mongodb-4.2.3.jar:4.2.3]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:281) ~[spring-core-6.1.4.jar:6.1.4]
	at org.springframework.data.mapping.callback.EntityCallbackDiscoverer.lambda$computeCallbackInvokerFunction$1(EntityCallbackDiscoverer.java:258) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.callback.DefaultReactiveEntityCallbacks$DefaultReactiveEntityCallbackInvoker.invokeCallback(DefaultReactiveEntityCallbacks.java:110) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at org.springframework.data.mapping.callback.DefaultReactiveEntityCallbacks.lambda$callback$1(DefaultReactiveEntityCallbacks.java:91) ~[spring-data-commons-3.2.3.jar:3.2.3]
	at reactor.core.publisher.FluxFlatMap.trySubscribeScalarMap(FluxFlatMap.java:153) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoFlatMap.subscribeOrReturn(MonoFlatMap.java:53) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:63) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:165) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:210) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2571) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.request(FluxPeekFuseable.java:144) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.request(MonoFlatMap.java:194) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.request(FluxMapFuseable.java:171) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.request(MonoFlatMap.java:194) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.request(MonoFlatMap.java:194) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.FluxUsingWhen$UsingWhenSubscriber.request(FluxUsingWhen.java:322) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.request(FluxPeekFuseable.java:783) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.request(MonoPeekTerminal.java:139) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.BlockingSingleSubscriber.onSubscribe(BlockingSingleSubscriber.java:53) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onSubscribe(MonoPeekTerminal.java:152) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onSubscribe(FluxPeekFuseable.java:816) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.FluxUsingWhen$UsingWhenSubscriber.onSubscribe(FluxUsingWhen.java:411) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.onSubscribe(MonoFlatMap.java:117) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.onSubscribe(MonoFlatMap.java:117) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onSubscribe(FluxMapFuseable.java:96) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.onSubscribe(MonoFlatMap.java:117) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onSubscribe(FluxPeekFuseable.java:178) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:55) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:76) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.MonoUsingWhen.subscribe(MonoUsingWhen.java:87) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.Mono.subscribe(Mono.java:4563) ~[reactor-core-3.6.3.jar:3.6.3]
	at reactor.core.publisher.Mono.block(Mono.java:1778) ~[reactor-core-3.6.3.jar:3.6.3]
	at cab.tapsi.springmongotest.ApplicationRunner.run(ApplicationRunner.kt:44) ~[main/:na]
	at org.springframework.boot.SpringApplication.lambda$callRunner$5(SpringApplication.java:790) ~[spring-boot-3.2.3.jar:3.2.3]
	at org.springframework.util.function.ThrowingConsumer$1.acceptWithException(ThrowingConsumer.java:83) ~[spring-core-6.1.4.jar:6.1.4]
	at org.springframework.util.function.ThrowingConsumer.accept(ThrowingConsumer.java:60) ~[spring-core-6.1.4.jar:6.1.4]
	at org.springframework.util.function.ThrowingConsumer$1.accept(ThrowingConsumer.java:88) ~[spring-core-6.1.4.jar:6.1.4]
	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:798) ~[spring-boot-3.2.3.jar:3.2.3]
	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:789) ~[spring-boot-3.2.3.jar:3.2.3]
	at org.springframework.boot.SpringApplication.lambda$callRunners$3(SpringApplication.java:774) ~[spring-boot-3.2.3.jar:3.2.3]
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183) ~[na:na]
	at java.base/java.util.stream.SortedOps$SizedRefSortingSink.end(SortedOps.java:357) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:510) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) ~[na:na]
	at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:774) ~[spring-boot-3.2.3.jar:3.2.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:341) ~[spring-boot-3.2.3.jar:3.2.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1354) ~[spring-boot-3.2.3.jar:3.2.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-3.2.3.jar:3.2.3]
	at cab.tapsi.springmongotest.SpringMongoTestApplicationKt.main(SpringMongoTestApplication.kt:15) ~[main/:an]

The classes are defined as follows:

@Document(collection = "stores")
data class Store(
  @Id val id: String? = null,
  @Indexed(unique = true) val slug: String,
  @Indexed(unique = true) val ownerId: String,
  val name: String,
  val preferences: StorePreferences,
  @CreatedDate val createdTimestamp: Timestamp? = null,
  @LastModifiedDate val updatedTimestamp: Timestamp? = null,
)


data class StorePreferences(
  val workingTimeslots: Map<DayOfWeek, HashSet<TimeslotOffset>> = emptyMap(),
  val processingDurationInSeconds: Long = 0,
)

data class TimeslotOffset(
  val startOffset: Long,
  val endOffset: Long,
)

Also, in this link, I have created a project where you can reproduce the error. Also, you can see the correct way of working by removing the @EnableReactiveMongoAuditing annotation.

This problem arose after upgrading Spring Boot from version 2.5.X to version 3.2.3.
Java version:

openjdk version "17.0.9" 2023-10-17
OpenJDK Runtime Environment (build 17.0.9+9-Ubuntu-122.04)
OpenJDK 64-Bit Server VM (build 17.0.9+9-Ubuntu-122.04, mixed mode, sharing)

[scottfrederick]

@mahdibohloul It does not appear that Spring Boot is involved in this error, but that it is an issue for Spring Data MongoDB. There is a similar issue in the Spring Data MongoDB repository that was closed due to inactivity. A work-around suggested there is to provide an --add-opens option to the JVM, and that suggestion does allow your sample to get past the error. To test this, run your sample with:

java --add-opens java.base/java.util=ALL-UNNAMED -jar build/libs/spring-mongo-test-0.0.1-SNAPSHOT.jar

For additional help, please comment on the Spring Data MongoDB issue or open a new issue in that project's repository.