springcloud-gateway报错cannot be cast to org.springframework.core.io.buffer.NettyDataBufferFactory

参考网上的文章学着写一个最简单的springcloud-gateway工程，没想到居然爆出如下错误：

2020-03-03 10:11:22.375 ERROR 21124 --- [ctor-http-nio-1] a.w.r.e.AbstractErrorWebExceptionHandler : [192daec8]  500 Server Error for HTTP GET "/test"

java.lang.ClassCastException: org.springframework.core.io.buffer.DefaultDataBufferFactory cannot be cast to org.springframework.core.io.buffer.NettyDataBufferFactory
	at org.springframework.cloud.gateway.filter.NettyWriteResponseFilter.lambda$filter$1(NettyWriteResponseFilter.java:82) ~[spring-cloud-gateway-core-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
	|_ checkpoint ⇢ org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter [DefaultWebFilterChain]
	|_ checkpoint ⇢ HTTP GET "/test" [ExceptionHandlingWebHandler]
Stack trace:
		at org.springframework.cloud.gateway.filter.NettyWriteResponseFilter.lambda$filter$1(NettyWriteResponseFilter.java:82) ~[spring-cloud-gateway-core-2.2.1.RELEASE.jar:2.2.1.RELEASE]
		at org.springframework.cloud.gateway.filter.NettyWriteResponseFilter$$Lambda$616/1894407985.get(Unknown Source) ~[na:na]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:44) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:153) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.ignoreDone(MonoIgnoreThen.java:190) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreInner.onComplete(MonoIgnoreThen.java:240) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onComplete(MonoPeekTerminal.java:292) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.Operators$MonoSubscriber.onComplete(Operators.java:1747) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen$ThenAcceptInner.onComplete(MonoIgnoreThen.java:314) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.Operators.complete(Operators.java:135) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoEmpty.subscribe(MonoEmpty.java:45) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:153) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.ignoreDone(MonoIgnoreThen.java:190) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreInner.onComplete(MonoIgnoreThen.java:240) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2269) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoFlatMapMany$FlatMapManyMain.onSubscribeInner(MonoFlatMapMany.java:143) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoFlatMapMany$FlatMapManyMain.onNext(MonoFlatMapMany.java:182) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.FluxRetryPredicate$RetryPredicateSubscriber.onNext(FluxRetryPredicate.java:82) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.core.publisher.MonoCreate$DefaultMonoSink.success(MonoCreate.java:156) [reactor-core-3.3.3.RELEASE.jar:3.3.3.RELEASE]
		at reactor.netty.http.client.HttpClientConnect$HttpObserver.onStateChange(HttpClientConnect.java:398) [reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]
		at reactor.netty.ReactorNetty$CompositeConnectionObserver.onStateChange(ReactorNetty.java:514) [reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]
		at reactor.netty.resources.PooledConnectionProvider$DisposableAcquire.onStateChange(PooledConnectionProvider.java:501) [reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]
		at reactor.netty.resources.PooledConnectionProvider$PooledConnection.onStateChange(PooledConnectionProvider.java:413) [reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]
		at reactor.netty.http.client.HttpClientOperations.onInboundNext(HttpClientOperations.java:550) [reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]
		at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:90) [reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:436) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:321) [netty-codec-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:308) [netty-codec-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:422) [netty-codec-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276) [netty-codec-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1470) [netty-handler-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1219) [netty-handler-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1266) [netty-handler-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:498) [netty-codec-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:437) [netty-codec-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276) [netty-codec-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:714) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493) [netty-transport-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989) [netty-common-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) [netty-common-4.1.45.Final.jar:4.1.45.Final]
		at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [netty-common-4.1.45.Final.jar:4.1.45.Final]
		at java.lang.Thread.run(Thread.java:745) [na:1.8.0_31]

紧接着面向百度编程，发现了问题所在，gateway工程和spring-boot-starter-web以及spring-boot-starter-tomcat是相冲突的，要在pom.xml文件中声明排除掉springboot-webmvc和springboot-tomcat。

 
      
          org.springframework
          spring-boot-starter-web
      
      
          org.springframework.bootk
          spring-boot-starter-tomcat
      
 

但是我本来就是一个简简单单的demo，所以，直接注释掉pom.xml中的这个两个依赖即可，如下

 

• 参考文献：

https://www.cnblogs.com/bluersw/p/11610705.html

https://blog.csdn.net/sinat_37909570/article/details/84984016

https://blog.csdn.net/yichen0429/article/details/98203775?depth_1-utm_source=distribute.pc_relevant.none-task&utm_source=distribute.pc_relevant.none-task