java.lang.IllegalStateException:

作者使用Rsocket客户端调用服务端时。只导入webflux的依赖如下：

<!--webflux-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-webflux</artifactId>
</dependency>

因为客户端使用了.block()方法，所以出现了如下的错误：

java.lang.IllegalStateException: block()/blockFirst()/blockLast() are blocking, which is not supported in thread reactor-http-nio-2
    at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:83) ~[reactor-core-3.4.9.jar:3.4.9]
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
    |_ checkpoint ⇢ springfox.boot.starter.autoconfigure.SwaggerUiWebFluxConfiguration$CustomWebFilter [DefaultWebFilterChain]
    |_ checkpoint ⇢ HTTP GET "/odc.data.test2?num=1" [ExceptionHandlingWebHandler]
Stack trace:
        at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:83) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Mono.block(Mono.java:1704) ~[reactor-core-3.4.9.jar:3.4.9]
        at cn.opendatachain.controller.Test2Controller.test2(Test2Controller.java:116) ~[classes/:na]
        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.reactive.result.method.InvocableHandlerMethod.lambda$invoke$0(InvocableHandlerMethod.java:146) ~[spring-webflux-5.3.9.jar:5.3.9]
        at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:125) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1816) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoZip$ZipCoordinator.signal(MonoZip.java:251) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoZip$ZipInner.onNext(MonoZip.java:336) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onNext(MonoPeekTerminal.java:180) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxDefaultIfEmpty$DefaultIfEmptySubscriber.onNext(FluxDefaultIfEmpty.java:101) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:74) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2398) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:2194) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:2068) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxFlatMap.trySubscribeScalarMap(FluxFlatMap.java:192) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoFlatMap.subscribeOrReturn(MonoFlatMap.java:53) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Mono.subscribe(Mono.java:4323) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoZip.subscribe(MonoZip.java:128) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:64) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.subscribeNext(MonoIgnoreThen.java:236) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.onComplete(MonoIgnoreThen.java:203) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoFlatMap$FlatMapMain.onComplete(MonoFlatMap.java:181) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Operators.complete(Operators.java:137) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoZip.subscribe(MonoZip.java:120) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Mono.subscribe(Mono.java:4338) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.subscribeNext(MonoIgnoreThen.java:255) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:51) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:64) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:157) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:74) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:82) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerNext(FluxConcatMap.java:282) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:861) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:127) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onNext(MonoPeekTerminal.java:180) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2398) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.request(MonoPeekTerminal.java:139) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.request(FluxMapFuseable.java:169) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:2194) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:2068) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onSubscribe(FluxMapFuseable.java:96) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onSubscribe(MonoPeekTerminal.java:152) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:55) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Mono.subscribe(Mono.java:4338) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:449) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:219) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:164) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:86) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:64) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:64) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.Mono.subscribe(Mono.java:4338) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.subscribeNext(MonoIgnoreThen.java:255) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:51) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:64) ~[reactor-core-3.4.9.jar:3.4.9]
        at reactor.netty.http.server.HttpServer$HttpServerHandle.onStateChange(HttpServer.java:915) ~[reactor-netty-http-1.0.10.jar:1.0.10]
        at reactor.netty.ReactorNetty$CompositeConnectionObserver.onStateChange(ReactorNetty.java:654) ~[reactor-netty-core-1.0.10.jar:1.0.10]
        at reactor.netty.transport.ServerTransport$ChildObserver.onStateChange(ServerTransport.java:478) ~[reactor-netty-core-1.0.10.jar:1.0.10]
        at reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:517) ~[reactor-netty-http-1.0.10.jar:1.0.10]
        at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:93) ~[reactor-netty-core-1.0.10.jar:1.0.10]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:208) ~[reactor-netty-http-1.0.10.jar:1.0.10]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:436) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:324) ~[netty-codec-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:296) ~[netty-codec-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493) ~[netty-transport-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986) ~[netty-common-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.67.Final.jar:4.1.67.Final]
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.67.Final.jar:4.1.67.Final]
        at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

解决方法：
因为没有同步web包，调用.block()就会有如下方法，所以要导入同步包，或者不使用.block()方法。
导入下面的依赖就会好

<!--web-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>