Random null pointer exception in 1.3.1

[abernerus]

This happens almost every time when using 1.3.1, but I have never seen it in 1.3.0. see stacktrace below.

Spring boot app
Spring boot: 2.2.6.RELEASE
Using webflux, running on Netty

spring doc and swagger dependencies:

        <dependency>
            <groupId>org.springdoc</groupId>
            <artifactId>springdoc-openapi-webflux-ui</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency>
            <groupId>io.swagger.core.v3</groupId>
            <artifactId>swagger-models</artifactId>
            <version>2.1.2</version>
        </dependency>

Sorry I can not post my code, but changing back to 1.3.0 solves the issue.

Also when I don't get the null pointer I will get java.util.ConcurrentModificationException: null
then the UI loads anyway.

NPE exception stacktrace:

java.lang.NullPointerException: null
	at org.springdoc.api.AbstractOpenApiResource.calculatePath(AbstractOpenApiResource.java:161) ~[springdoc-openapi-common-1.3.1.jar:1.3.1]
	Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException:
Error has been observed at the following site(s):
	|_ checkpoint ⇢ org.springframework.security.web.server.authorization.AuthorizationWebFilter [DefaultWebFilterChain]
	|_ checkpoint ⇢ org.springframework.security.web.server.authorization.ExceptionTranslationWebFilter [DefaultWebFilterChain]
	|_ checkpoint ⇢ org.springframework.security.web.server.authentication.logout.LogoutWebFilter [DefaultWebFilterChain]
	|_ checkpoint ⇢ org.springframework.security.web.server.savedrequest.ServerRequestCacheWebFilter [DefaultWebFilterChain]
	|_ checkpoint ⇢ org.springframework.security.web.server.context.SecurityContextServerWebExchangeWebFilter [DefaultWebFilterChain]
	|_ checkpoint ⇢ org.springframework.security.web.server.context.ReactorContextWebFilter [DefaultWebFilterChain]
	|_ checkpoint ⇢ org.springframework.security.web.server.header.HttpHeaderWriterWebFilter [DefaultWebFilterChain]
	|_ checkpoint ⇢ org.springframework.security.config.web.server.ServerHttpSecurity$ServerWebExchangeReactorContextWebFilter [DefaultWebFilterChain]
	|_ checkpoint ⇢ org.springframework.security.web.server.WebFilterChainProxy [DefaultWebFilterChain]
	|_ checkpoint ⇢ org.springframework.boot.actuate.metrics.web.reactive.server.MetricsWebFilter [DefaultWebFilterChain]
	|_ checkpoint ⇢ HTTP GET "/api-docs" [ExceptionHandlingWebHandler]
Stack trace:
		at org.springdoc.api.AbstractOpenApiResource.calculatePath(AbstractOpenApiResource.java:161) ~[springdoc-openapi-common-1.3.1.jar:1.3.1]
		at org.springdoc.webflux.api.OpenApiResource.getPaths(OpenApiResource.java:110) ~[springdoc-openapi-webflux-core-1.3.1.jar:1.3.1]
		at org.springdoc.api.AbstractOpenApiResource.getOpenApi(AbstractOpenApiResource.java:140) ~[springdoc-openapi-common-1.3.1.jar:1.3.1]
		at org.springdoc.webflux.api.OpenApiResource.openapiJson(OpenApiResource.java:79) ~[springdoc-openapi-webflux-core-1.3.1.jar:1.3.1]
		at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
		at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]
		at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
		at java.lang.reflect.Method.invoke(Method.java:567) ~[?:?]
		at org.springframework.web.reactive.result.method.InvocableHandlerMethod.lambda$invoke$0(InvocableHandlerMethod.java:147) ~[spring-webflux-5.2.5.RELEASE.jar:5.2.5.RELEASE]
		at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:118) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1712) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoZip$ZipCoordinator.signal(MonoZip.java:247) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoZip$ZipInner.onNext(MonoZip.java:329) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onNext(MonoPeekTerminal.java:173) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxDefaultIfEmpty$DefaultIfEmptySubscriber.onNext(FluxDefaultIfEmpty.java:92) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1712) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoSupplier.subscribe(MonoSupplier.java:61) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Mono.subscribe(Mono.java:4210) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onComplete(FluxSwitchIfEmpty.java:75) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators.complete(Operators.java:135) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFlatMap.trySubscribeScalarMap(FluxFlatMap.java:144) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoFlatMap.subscribeOrReturn(MonoFlatMap.java:53) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Mono.subscribe(Mono.java:4195) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoZip.subscribe(MonoZip.java:128) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:153) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:76) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerNext(FluxConcatMap.java:274) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:851) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:121) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onNext(MonoPeekTerminal.java:173) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2274) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.request(MonoPeekTerminal.java:132) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.request(FluxMapFuseable.java:162) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:2082) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:1956) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onSubscribe(FluxMapFuseable.java:90) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onSubscribe(MonoPeekTerminal.java:145) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:54) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Mono.subscribe(Mono.java:4210) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:441) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:211) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:161) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:86) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Mono.subscribe(Mono.java:4210) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onComplete(FluxSwitchIfEmpty.java:75) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:141) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFilter$FilterSubscriber.onNext(FluxFilter.java:107) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxDefaultIfEmpty$DefaultIfEmptySubscriber.onNext(FluxDefaultIfEmpty.java:92) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:76) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerNext(FluxConcatMap.java:274) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:851) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1712) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:144) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFilter$FilterSubscriber.onNext(FluxFilter.java:107) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:76) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFilter$FilterSubscriber.onNext(FluxFilter.java:107) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFlatMap$FlatMapMain.tryEmitScalar(FluxFlatMap.java:478) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFlatMap$FlatMapMain.onNext(FluxFlatMap.java:413) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable$IterableSubscription.slowPath(FluxIterable.java:267) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable$IterableSubscription.request(FluxIterable.java:225) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFlatMap$FlatMapMain.onSubscribe(FluxFlatMap.java:363) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:161) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:86) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Mono.subscribe(Mono.java:4210) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:441) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:211) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:161) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:86) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Mono.subscribe(Mono.java:4210) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:172) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Mono.subscribe(Mono.java:4210) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onComplete(FluxSwitchIfEmpty.java:75) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFilter$FilterSubscriber.onComplete(FluxFilter.java:160) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onComplete(FluxSwitchIfEmpty.java:78) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2276) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:2082) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:1956) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:54) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Mono.subscribe(Mono.java:4210) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onComplete(FluxSwitchIfEmpty.java:75) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoNext$NextSubscriber.onComplete(MonoNext.java:96) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFilter$FilterSubscriber.onComplete(FluxFilter.java:160) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFlatMap$FlatMapMain.checkTerminated(FluxFlatMap.java:823) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFlatMap$FlatMapMain.drainLoop(FluxFlatMap.java:589) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFlatMap$FlatMapMain.drain(FluxFlatMap.java:569) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFlatMap$FlatMapMain.onComplete(FluxFlatMap.java:455) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable$IterableSubscription.slowPath(FluxIterable.java:289) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable$IterableSubscription.request(FluxIterable.java:225) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFlatMap$FlatMapMain.onSubscribe(FluxFlatMap.java:363) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:161) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:86) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1712) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxDefaultIfEmpty$DefaultIfEmptySubscriber.onComplete(FluxDefaultIfEmpty.java:100) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators.complete(Operators.java:135) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoEmpty.subscribe(MonoEmpty.java:45) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:121) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:121) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1712) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoFlatMap$FlatMapInner.onNext(MonoFlatMap.java:241) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1712) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoCollectList$MonoCollectListSubscriber.onComplete(MonoCollectList.java:121) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable$IterableSubscription.fastPath(FluxIterable.java:357) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable$IterableSubscription.request(FluxIterable.java:222) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoCollectList$MonoCollectListSubscriber.onSubscribe(MonoCollectList.java:72) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:161) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:86) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoFromFluxOperator.subscribe(MonoFromFluxOperator.java:72) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:76) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFilterWhen$FluxFilterWhenSubscriber.drain(FluxFilterWhen.java:295) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFilterWhen$FluxFilterWhenSubscriber.onNext(FluxFilterWhen.java:134) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable$IterableSubscription.slowPath(FluxIterable.java:267) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable$IterableSubscription.request(FluxIterable.java:225) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxFilterWhen$FluxFilterWhenSubscriber.onSubscribe(FluxFilterWhen.java:194) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:161) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:86) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.Mono.subscribe(Mono.java:4210) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:172) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) [reactor-core-3.3.4.RELEASE.jar:3.3.4.RELEASE]
		at reactor.netty.http.server.HttpServerHandle.onStateChange(HttpServerHandle.java:64) [reactor-netty-0.9.6.RELEASE.jar:0.9.6.RELEASE]
		at reactor.netty.tcp.TcpServerBind$ChildObserver.onStateChange(TcpServerBind.java:228) [reactor-netty-0.9.6.RELEASE.jar:0.9.6.RELEASE]
		at reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:465) [reactor-netty-0.9.6.RELEASE.jar:0.9.6.RELEASE]
		at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:90) [reactor-netty-0.9.6.RELEASE.jar:0.9.6.RELEASE]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:170) [reactor-netty-0.9.6.RELEASE.jar:0.9.6.RELEASE]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:436) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:321) [netty-codec-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:295) [netty-codec-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:714) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493) [netty-transport-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989) [netty-common-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) [netty-common-4.1.48.Final.jar:4.1.48.Final]
		at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [netty-common-4.1.48.Final.jar:4.1.48.Final]
		at java.lang.Thread.run(Thread.java:830) [?:?]

[abernerus]

This is my OpenAPI config bean:

return new OpenAPI()
                .components(new Components()
                        .addSecuritySchemes("myApiKey", new SecurityScheme()
                                .type(Type.APIKEY)
                                .name("apiKey")
                                .in(In.HEADER)
                                .description("Enter your apiKey")
                        )
                )
                .security(Collections.singletonList(new SecurityRequirement().addList("myApiKey")))
                .info(new Info()
                        .title(applicationName + " API")
                        .version(apiVersion)
                        .description("")
                );

[bnasslahsen]

@abernerus,

First of all, you don't need to declare swagger-models dependency, as it is transitively shipped by springdoc-openapi-webflux-ui.

If you are reporting a bug, please help to speed up problem diagnosis by providing as much information as possible:

• Do you have a sample code to reproduce ? Or Provide with a sample code (HelloController) or Test that reproduces the problem?

[abernerus]

Hi, yes I totally understand about the code part, I'll see if I can create some dummy service tomorrow without any customer related things...

Anyway it seems to occur more often with when there are rest controllers with many endpoints, I tried to name them all and also adding operationId, it felt like it helped a bit but I'm not really sure tbh.

Edit:
The reason I did this is because the error in GUI is:
Fetch errorInternal Server Error /api-docs
Parser error duplicated mapping key

[marklagendijk]

I'm also seeing that error on the frontend:

Parser error 
duplicated mapping key

The problematic open-api response has the following format:

{
	"paths": {
            "/my-endpoint": {
                "get": {}
            },
            "/my-endpoint": {
                "put": {}
            }
        }

So the problem is that when there are multiple methods for the same path, it can happen that they are not put under the same paths key in the JSON response, making the JSON invalid.

I think that #206 may also be related. It may be that this is caused by an concurrency issue, and therefore it may be hard to reproduce.

[marklagendijk]

After some more investigation I saw the following:

• Swagger UI does 2 identical request to the swagger-config endpoint, and then 2 identical requests to the api-docs endpoint.
• The api-docs endpoints sometimes throws an exception. See the stacktraces below.
• The api-docs endpoint sometimes generates the duplicated paths keys as shown in my previous comment.

My guess is that the issue is that the api-docs endpoint cannot handle concurrent requests properly. Because Swagger UI wrongly requests the api-docs twice, the concurrency issue is triggered. Because it is a concurrency issue, it only occurs if the conditions are right (large enough dataset?).

java.lang.NullPointerException: null
	at io.swagger.v3.core.filter.SpecFilter.addPathItemSchemaRef(SpecFilter.java:357) ~[swagger-core-2.1.2.jar:2.1.2]
	at io.swagger.v3.core.filter.SpecFilter.removeBrokenReferenceDefinitions(SpecFilter.java:410) ~[swagger-core-2.1.2.jar:2.1.2]
	at org.springdoc.api.AbstractOpenApiResource.getOpenApi(AbstractOpenApiResource.java:144) ~[springdoc-openapi-common-1.3.1.jar:1.3.1]
	at org.springdoc.webmvc.api.OpenApiResource.openapiJson(OpenApiResource.java:92) ~[springdoc-openapi-webmvc-core-1.3.1.jar:1.3.1]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[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:566) ~[na:na]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.web.servlet.resource.ResourceUrlEncodingFilter.doFilter(ResourceUrlEncodingFilter.java:64) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:118) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:158) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:117) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:92) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:77) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.session.web.http.SessionRepositoryFilter.doFilterInternal(SessionRepositoryFilter.java:141) ~[spring-session-core-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.session.web.http.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:82) ~[spring-session-core-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:109) ~[spring-boot-actuator-2.2.5.RELEASE.jar:2.2.5.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]

java.util.ConcurrentModificationException: null
	at java.base/java.util.LinkedHashMap$LinkedHashIterator.nextNode(LinkedHashMap.java:719) ~[na:na]
	at java.base/java.util.LinkedHashMap$LinkedValueIterator.next(LinkedHashMap.java:746) ~[na:na]
	at org.springdoc.core.OperationBuilder.existOperationId(OperationBuilder.java:244) ~[springdoc-openapi-common-1.3.1.jar:1.3.1]
	at org.springdoc.core.OperationBuilder.getOperationId(OperationBuilder.java:224) ~[springdoc-openapi-common-1.3.1.jar:1.3.1]
	at org.springdoc.core.OperationBuilder.getOperationId(OperationBuilder.java:402) ~[springdoc-openapi-common-1.3.1.jar:1.3.1]
	at org.springdoc.core.AbstractRequestBuilder.build(AbstractRequestBuilder.java:157) ~[springdoc-openapi-common-1.3.1.jar:1.3.1]
	at org.springdoc.api.AbstractOpenApiResource.calculatePath(AbstractOpenApiResource.java:217) ~[springdoc-openapi-common-1.3.1.jar:1.3.1]
	at org.springdoc.webmvc.api.OpenApiResource.calculatePath(OpenApiResource.java:142) ~[springdoc-openapi-webmvc-core-1.3.1.jar:1.3.1]
	at org.springdoc.webmvc.api.OpenApiResource.getPaths(OpenApiResource.java:108) ~[springdoc-openapi-webmvc-core-1.3.1.jar:1.3.1]
	at org.springdoc.api.AbstractOpenApiResource.getOpenApi(AbstractOpenApiResource.java:140) ~[springdoc-openapi-common-1.3.1.jar:1.3.1]
	at org.springdoc.webmvc.api.OpenApiResource.openapiJson(OpenApiResource.java:92) ~[springdoc-openapi-webmvc-core-1.3.1.jar:1.3.1]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[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:566) ~[na:na]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.web.servlet.resource.ResourceUrlEncodingFilter.doFilter(ResourceUrlEncodingFilter.java:64) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:118) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:158) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:117) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:92) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:77) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.session.web.http.SessionRepositoryFilter.doFilterInternal(SessionRepositoryFilter.java:141) ~[spring-session-core-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.session.web.http.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:82) ~[spring-session-core-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:109) ~[spring-boot-actuator-2.2.5.RELEASE.jar:2.2.5.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31]

[bnasslahsen]

@abernerus,

If you are reporting a bug, please help to speed up problem diagnosis by providing as much information as possible:

• Can you provide a sample code (HelloController) or Test that reproduces the problem ?

For the fact that request is triggered twice from the swagger-ui. Its a know swagger issues:

• Configuration file downloaded 2 times when using configUrl swagger-api/swagger-ui#4825

However, we can handle it in springdoc, if we get to know the exact root cause. Otherwise, we will add the synchronized ...

[abernerus]

Yes I've seen the concurrent modification exception as well.
Sorry I haven't got the time to set up a hello controller, hopefully I'll get the time during or after easer holidays.

Anyway, yes the config endpoint is called twice, but this also happens on version 1.3.0 where I never get these errors...

The error reported in frontend is as you say @marklagendijk is duplicated key

[marklagendijk]

When I change the configUrl to the json url like this: index.html?configUrl=PATH/swagger-config to index.html?url=PATH/api-docs, it will request the JSON only once.

I tested using this url, and with this it works consistently. I tried restarting the application several times.

So my conclusion is that the issue is indeed caused by simultaneous requests to the JSON endpoint.

[abernerus]

I got a workaround running by providing a custom swagger-ui/index.html file with my api-docs path in it, (and not the pet-store url). I don't know the underlying logic here, but the pet-store example was loaded when I triggered some errors on my side, leading me to believe that somethings fishy with the javascript, which indeed loads everything twice as you said Mark.

Also I fished up the json results when it gets an error, and there are indeed duplicated keys in the returned json map. probably because of the simultaneous requests and some funny logic in BE code... Hopefully it cannot be triggered with a lot of simultaneous users...

Anyway I won't have time to investigate this more atm. I'll live with my workaround for now

[bnasslahsen]

@abernerus,
This issue had bien already fixed in v1.3.2.

[yarabchukx]

@bnasslahsen The issue with Swagger UI loading everything twice is still present in v1.3.8

[bnasslahsen]

@yarabchukx,

This is not related to springdoc-openapi.
Its related to swagger-ui behaviour. You should log your comment on the previously mentionned issue: swagger-api/swagger-ui#4825.

Anyway, this behavour is correctly handled on springdoc-openapi side to cache already processed requests ...

[bnasslahsen]

@yarabchukx , @abernerus, @marklagendijk ,

Starting from v1.4.1, the following properties can be used to prevent the load of the swagger-config twice.
Please note this properties works only in the case where there is no groups (no multiple urls and no configUrl set on the swagger-ui):

• If your REST APIs, are not using OAuth2:

springdoc.swagger-ui.display-query-params-without-oauth2=true

• If your REST APIs, are using OAuth2:

springdoc.swagger-ui.display-query-params=true