After upgrading to Spring Boot 4.0.6, we started to face an issue with nullable value classes as query parameters.
You can find a project reproducing this issue at https://github.com/joaodias14/demo-nullable-value-classes.
If we make an HTTP request (GET http://localhost:8080/nullable-value-classes?nonNullableValueClass=test1&nullableValueClass=test2) to an endpoint that has a nullable value class as a query parameter and we include it, the following error is thrown:
java.lang.IllegalStateException: object of type java.lang.String is not an instance of com.example.demo.ValueClass
Handler [com.example.demo.ExampleController]
Method [public java.lang.String com.example.demo.ExampleController.testValueClasses-r--EhOU(java.lang.String,java.lang.String)] with argument values:
[0] [type=java.lang.String] [value=test1],
[1] [type=java.lang.String] [value=test2]
at org.springframework.web.reactive.result.method.InvocableHandlerMethod.lambda$invoke$0(InvocableHandlerMethod.java:211) ~[spring-webflux-7.0.7.jar:7.0.7]
Suppressed: The stacktrace has been enhanced by Reactor, refer to additional information below:
Error has been observed at the following site(s):
*__checkpoint ⇢ HTTP GET "/nullable-value-classes?nonNullableValueClass=test1&nullableValueClass=test2" [ExceptionHandlingWebHandler]
Original Stack Trace:
at org.springframework.web.reactive.result.method.InvocableHandlerMethod.lambda$invoke$0(InvocableHandlerMethod.java:211) ~[spring-webflux-7.0.7.jar:7.0.7]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:132) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoZip$ZipCoordinator.signal(MonoZip.java:296) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoZip$ZipInner.onNext(MonoZip.java:479) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onNext(MonoPeekTerminal.java:184) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxDefaultIfEmpty$DefaultIfEmptySubscriber.onNext(FluxDefaultIfEmpty.java:122) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:75) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2564) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:2361) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:2235) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxFlatMap.trySubscribeScalarMap(FluxFlatMap.java:193) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap.subscribeOrReturn(MonoFlatMap.java:53) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:62) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoZip$ZipCoordinator.request(MonoZip.java:219) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.request(MonoFlatMap.java:194) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.onSubscribe(MonoIgnoreThen.java:135) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.onSubscribe(MonoFlatMap.java:117) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoZip.subscribe(MonoZip.java:129) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:75) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:54) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.subscribeNext(MonoIgnoreThen.java:244) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.onComplete(MonoIgnoreThen.java:207) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.onComplete(MonoFlatMap.java:189) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators.complete(Operators.java:137) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoZip.subscribe(MonoZip.java:121) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Mono.subscribe(Mono.java:4569) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.subscribeNext(MonoIgnoreThen.java:268) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:51) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:75) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:165) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onNext(FluxOnErrorResume.java:80) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:75) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:83) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxConcatMapNoPrefetch$FluxConcatMapNoPrefetchSubscriber.innerNext(FluxConcatMapNoPrefetch.java:258) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:868) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.secondComplete(MonoFlatMap.java:245) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapInner.onNext(MonoFlatMap.java:306) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:130) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onNext(MonoPeekTerminal.java:184) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2564) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.request(MonoPeekTerminal.java:142) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.request(FluxMapFuseable.java:172) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapInner.onSubscribe(MonoFlatMap.java:292) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onSubscribe(FluxMapFuseable.java:96) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onSubscribe(MonoPeekTerminal.java:155) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:56) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:75) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:165) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:211) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2564) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.request(FluxPeekFuseable.java:144) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.request(MonoFlatMap.java:194) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:2361) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:2235) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.onSubscribe(MonoFlatMap.java:117) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onSubscribe(FluxPeekFuseable.java:178) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:56) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Mono.subscribe(Mono.java:4569) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxConcatMapNoPrefetch$FluxConcatMapNoPrefetchSubscriber.onNext(FluxConcatMapNoPrefetch.java:206) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxIterable$IterableSubscription.slowPath(FluxIterable.java:335) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxIterable$IterableSubscription.request(FluxIterable.java:294) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxConcatMapNoPrefetch$FluxConcatMapNoPrefetchSubscriber.innerComplete(FluxConcatMapNoPrefetch.java:274) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onComplete(FluxConcatMap.java:892) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.secondComplete(MonoFlatMap.java:250) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapInner.onComplete(MonoFlatMap.java:325) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:144) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators.complete(Operators.java:137) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoEmpty.subscribe(MonoEmpty.java:46) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:75) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:165) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:211) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2564) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.request(FluxPeekFuseable.java:144) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.request(MonoFlatMap.java:194) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.request(Operators.java:2325) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxConcatMapNoPrefetch$FluxConcatMapNoPrefetchSubscriber.request(FluxConcatMapNoPrefetch.java:338) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoNext$NextSubscriber.request(MonoNext.java:109) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:2361) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:2235) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoNext$NextSubscriber.onSubscribe(MonoNext.java:71) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxConcatMapNoPrefetch$FluxConcatMapNoPrefetchSubscriber.onSubscribe(FluxConcatMapNoPrefetch.java:163) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:200) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:82) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:75) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:54) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.Mono.subscribe(Mono.java:4569) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.subscribeNext(MonoIgnoreThen.java:268) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:51) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:75) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.core.publisher.MonoDeferContextual.subscribe(MonoDeferContextual.java:56) ~[reactor-core-3.8.5.jar:3.8.5]
at reactor.netty.http.server.HttpServer$HttpServerHandle.onStateChange(HttpServer.java:1378) ~[reactor-netty-http-1.3.5.jar:1.3.5]
at reactor.netty.ReactorNetty$CompositeConnectionObserver.onStateChange(ReactorNetty.java:730) ~[reactor-netty-core-1.3.5.jar:1.3.5]
at reactor.netty.transport.ServerTransport$ChildObserver.onStateChange(ServerTransport.java:539) ~[reactor-netty-core-1.3.5.jar:1.3.5]
at reactor.netty.http.server.HttpServerOperations.handleDefaultHttpRequest(HttpServerOperations.java:878) ~[reactor-netty-http-1.3.5.jar:1.3.5]
at reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:804) ~[reactor-netty-http-1.3.5.jar:1.3.5]
at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:115) ~[reactor-netty-core-1.3.5.jar:1.3.5]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:280) ~[reactor-netty-http-1.3.5.jar:1.3.5]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:434) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:361) ~[netty-codec-base-4.2.12.Final.jar:4.2.12.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:325) ~[netty-codec-base-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:249) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1429) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:918) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:176) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.handle(AbstractNioChannel.java:445) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.nio.NioIoHandler$DefaultNioRegistration.handle(NioIoHandler.java:388) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.nio.NioIoHandler.processSelectedKey(NioIoHandler.java:596) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.nio.NioIoHandler.processSelectedKeysPlain(NioIoHandler.java:541) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.nio.NioIoHandler.processSelectedKeys(NioIoHandler.java:514) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.nio.NioIoHandler.run(NioIoHandler.java:484) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.SingleThreadIoEventLoop.runIo(SingleThreadIoEventLoop.java:225) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.channel.SingleThreadIoEventLoop.run(SingleThreadIoEventLoop.java:196) ~[netty-transport-4.2.12.Final.jar:4.2.12.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:1195) ~[netty-common-4.2.12.Final.jar:4.2.12.Final]
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.2.12.Final.jar:4.2.12.Final]
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.2.12.Final.jar:4.2.12.Final]
at java.base/java.lang.Thread.run(Thread.java:1474) ~[na:na]
Caused by: java.lang.IllegalArgumentException: object of type java.lang.String is not an instance of com.example.demo.ValueClass
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.checkReceiver(DirectMethodHandleAccessor.java:199) ~[na:na]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:100) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:565) ~[na:na]
If we do not include such query parameter (GET http://localhost:8080/nullable-value-classes?nonNullableValueClass=test1), it works as expected.
The exact same thing happens with suspending functions.
Getting back to Spring Boot 4.0.5 makes the error go away and both requests work as expected.
After upgrading to Spring Boot 4.0.6, we started to face an issue with nullable value classes as query parameters.
You can find a project reproducing this issue at https://github.com/joaodias14/demo-nullable-value-classes.
If we make an HTTP request (GET http://localhost:8080/nullable-value-classes?nonNullableValueClass=test1&nullableValueClass=test2) to an endpoint that has a nullable value class as a query parameter and we include it, the following error is thrown:
If we do not include such query parameter (GET http://localhost:8080/nullable-value-classes?nonNullableValueClass=test1), it works as expected.
The exact same thing happens with suspending functions.
Getting back to Spring Boot 4.0.5 makes the error go away and both requests work as expected.