如何在 webflux 中调试？
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【中文标题】如何在 webflux 中调试？【英文标题】：How to debug in webflux? 【发布时间】：2019-05-11 10:04:58 【问题描述】：我使用带有 webflux 的 Spring Boot 2.1.1.RELEASE。
依赖如下：
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
这里是控制器，我使用 Hooks.onOperatorDebug();正如reactor的文档所说，它可以打开调试模式。
@RestController
public class TestController
@GetMapping("/test")
public Mono test(String a)
Hooks.onOperatorDebug();
return Mono.just("test1")
.map(t -> t + "test2")
.zipWith(Mono.error(() -> new IllegalArgumentException("error")));
@PostMapping("/test")
public Mono post(@RequestBody Req req)
return Mono.just(req);
class Req
private String a;
private String b;
public String getA()
return a;
public void setA(String a)
this.a = a;
public String getB()
return b;
public void setB(String b)
this.b = b;
日志级别低于：
logging:
level:
root: trace
当我调用 http://localhost:8080/test> 时，我只能得到如下日志：
2018-12-10 21:41:17.001 DEBUG 31340 --- [ctor-http-nio-2] r.n.http.server.HttpServerOperations : [id: 0x7cc865b4, L:/0:0:0:0:0:0:0:1:8080 - R:/0:0:0:0:0:0:0:1:52638] Increasing pending responses, now 1
2018-12-10 21:41:17.001 DEBUG 31340 --- [ctor-http-nio-2] reactor.netty.http.server.HttpServer : [id: 0x7cc865b4, L:/0:0:0:0:0:0:0:1:8080 - R:/0:0:0:0:0:0:0:1:52638] Handler is being applied: org.springframework.http.server.reactive.ReactorHttpHandlerAdapter@3a0ad630
2018-12-10 21:41:17.002 TRACE 31340 --- [ctor-http-nio-2] o.s.w.s.adapter.HttpWebHandlerAdapter : [7cc865b4] HTTP GET "/test?a=b", headers=masked
2018-12-10 21:41:17.002 TRACE 31340 --- [ctor-http-nio-2] o.s.b.f.s.DefaultListableBeanFactory : Returning cached instance of singleton bean 'testController'
2018-12-10 21:41:17.002 DEBUG 31340 --- [ctor-http-nio-2] s.w.r.r.m.a.RequestMappingHandlerMapping : [7cc865b4] Mapped to public reactor.core.publisher.Mono com.itmuch.webfluxtest.TestController.test(java.lang.String)
2018-12-10 21:41:17.003 DEBUG 31340 --- [ctor-http-nio-2] reactor.core.publisher.Hooks : Enabling stacktrace debugging via onOperatorDebug
2018-12-10 21:41:17.003 DEBUG 31340 --- [ctor-http-nio-2] reactor.core.publisher.Hooks : Hooking onEachOperator: onOperatorDebug
2018-12-10 21:41:17.003 DEBUG 31340 --- [ctor-http-nio-2] o.s.w.r.r.m.a.ResponseBodyResultHandler : Using 'application/json;charset=UTF-8;q=0.8' given [text/html, application/xhtml+xml, image/webp, image/apng, application/xml;q=0.9, */*;q=0.8] and supported [application/json;charset=UTF-8, application/*+json;charset=UTF-8, text/event-stream]
2018-12-10 21:41:17.003 DEBUG 31340 --- [ctor-http-nio-2] o.s.w.r.r.m.a.ResponseBodyResultHandler : [7cc865b4] 0..1 [?]
2018-12-10 21:41:17.008 TRACE 31340 --- [ctor-http-nio-2] o.s.w.r.function.server.RouterFunctions : [7cc865b4] Matched org.springframework.boot.autoconfigure.web.reactive.error.DefaultErrorWebExceptionHandler$$Lambda$520/509612428@4c3d17a7
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'server.ports'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'configurationProperties'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'systemProperties'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'systemEnvironment'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'random'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'applicationConfig: [classpath:/application.yml]'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Could not find key 'spring.template.provider.cache' in any property source
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'server.ports'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'configurationProperties'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'systemProperties'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'systemEnvironment'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'random'
2018-12-10 21:41:17.009 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'applicationConfig: [classpath:/application.yml]'
2018-12-10 21:41:17.010 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Could not find key 'spring.template.provider.cache' in any property source
2018-12-10 21:41:17.010 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'server.ports'
2018-12-10 21:41:17.010 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'configurationProperties'
2018-12-10 21:41:17.010 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'systemProperties'
2018-12-10 21:41:17.010 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'systemEnvironment'
2018-12-10 21:41:17.010 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'random'
2018-12-10 21:41:17.010 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Searching for key 'spring.template.provider.cache' in PropertySource 'applicationConfig: [classpath:/application.yml]'
2018-12-10 21:41:17.010 TRACE 31340 --- [ctor-http-nio-2] o.s.c.e.PropertySourcesPropertyResolver : Could not find key 'spring.template.provider.cache' in any property source
2018-12-10 21:41:17.010 DEBUG 31340 --- [ctor-http-nio-2] .a.w.r.e.DefaultErrorWebExceptionHandler : [7cc865b4] Resolved [IllegalArgumentException: error] for HTTP GET /test
2018-12-10 21:41:17.011 TRACE 31340 --- [ctor-http-nio-2] o.s.core.codec.CharSequenceEncoder : [7cc865b4] Writing "<html><body><h1>Whitelabel Error Page</h1><p>This application has no configured error view, so you are seeing this as a fallback.</p><div id='created'>Mon Dec 10 21:41:17 CST 2018</div><div>There was an unexpected error (type=Internal Server Error, status=500).</div><div>error</div></body></html>"
2018-12-10 21:41:17.011 DEBUG 31340 --- [ctor-http-nio-2] r.n.channel.ChannelOperationsHandler : [id: 0x7cc865b4, L:/0:0:0:0:0:0:0:1:8080 - R:/0:0:0:0:0:0:0:1:52638] Writing object DefaultHttpResponse(decodeResult: success, version: HTTP/1.1)
HTTP/1.1 500 Internal Server Error
Content-Type: text/html
Content-Length: 297
2018-12-10 21:41:17.011 DEBUG 31340 --- [ctor-http-nio-2] r.n.channel.ChannelOperationsHandler : [id: 0x7cc865b4, L:/0:0:0:0:0:0:0:1:8080 - R:/0:0:0:0:0:0:0:1:52638] Writing object
2018-12-10 21:41:17.011 TRACE 31340 --- [ctor-http-nio-2] r.n.channel.ChannelOperationsHandler : [id: 0x7cc865b4, L:/0:0:0:0:0:0:0:1:8080 - R:/0:0:0:0:0:0:0:1:52638] Pending write size = 297
2018-12-10 21:41:17.012 TRACE 31340 --- [ctor-http-nio-2] o.s.w.s.adapter.HttpWebHandlerAdapter : [7cc865b4] Completed 500 INTERNAL_SERVER_ERROR, headers=masked
2018-12-10 21:41:17.012 TRACE 31340 --- [ctor-http-nio-2] o.s.h.s.r.ReactorHttpHandlerAdapter : [7cc865b4] Handling completed
2018-12-10 21:41:17.012 DEBUG 31340 --- [ctor-http-nio-2] r.n.http.server.HttpServerOperations : [id: 0x7cc865b4, L:/0:0:0:0:0:0:0:1:8080 - R:/0:0:0:0:0:0:0:1:52638] Last HTTP response frame
2018-12-10 21:41:17.012 DEBUG 31340 --- [ctor-http-nio-2] r.n.channel.ChannelOperationsHandler : [id: 0x7cc865b4, L:/0:0:0:0:0:0:0:1:8080 - R:/0:0:0:0:0:0:0:1:52638] Writing object EmptyLastHttpContent
2018-12-10 21:41:17.012 DEBUG 31340 --- [ctor-http-nio-2] r.n.http.server.HttpServerOperations : [id: 0x7cc865b4, L:/0:0:0:0:0:0:0:1:8080 - R:/0:0:0:0:0:0:0:1:52638] Decreasing pending responses, now 0
2018-12-10 21:41:17.013 TRACE 31340 --- [ctor-http-nio-2] reactor.netty.channel.ChannelOperations : [id: 0x7cc865b4, L:/0:0:0:0:0:0:0:1:8080 - R:/0:0:0:0:0:0:0:1:52638] Disposing ChannelOperation from a channel
java.lang.Exception: ChannelOperation terminal stack
at reactor.netty.channel.ChannelOperations.terminate(ChannelOperations.java:363) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at reactor.netty.http.server.HttpServerOperations.cleanHandlerTerminate(HttpServerOperations.java:509) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at reactor.netty.http.server.HttpTrafficHandler.operationComplete(HttpTrafficHandler.java:297) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at reactor.netty.http.server.HttpTrafficHandler.operationComplete(HttpTrafficHandler.java:54) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:511) [netty-common-4.1.31.Final.jar:4.1.31.Final]
at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:485) [netty-common-4.1.31.Final.jar:4.1.31.Final]
at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:424) [netty-common-4.1.31.Final.jar:4.1.31.Final]
at io.netty.util.concurrent.DefaultPromise.trySuccess(DefaultPromise.java:103) [netty-common-4.1.31.Final.jar:4.1.31.Final]
at io.netty.util.internal.PromiseNotificationUtil.trySuccess(PromiseNotificationUtil.java:48) [netty-common-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.ChannelOutboundBuffer.safeSuccess(ChannelOutboundBuffer.java:696) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.ChannelOutboundBuffer.remove(ChannelOutboundBuffer.java:258) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.nio.AbstractNioByteChannel.doWriteInternal(AbstractNioByteChannel.java:216) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.nio.AbstractNioByteChannel.doWrite0(AbstractNioByteChannel.java:209) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.socket.nio.NiosocketChannel.doWrite(NioSocketChannel.java:397) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannel$AbstractUnsafe.flush0(AbstractChannel.java:934) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.flush0(AbstractNioChannel.java:360) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannel$AbstractUnsafe.flush(AbstractChannel.java:901) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.flush(DefaultChannelPipeline.java:1396) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.flush(CombinedChannelDuplexHandler.java:533) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.ChannelOutboundHandlerAdapter.flush(ChannelOutboundHandlerAdapter.java:115) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.CombinedChannelDuplexHandler.flush(CombinedChannelDuplexHandler.java:358) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.ChannelDuplexHandler.flush(ChannelDuplexHandler.java:117) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at reactor.netty.channel.ChannelOperationsHandler.doWrite(ChannelOperationsHandler.java:283) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at reactor.netty.channel.ChannelOperationsHandler.drain(ChannelOperationsHandler.java:465) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at reactor.netty.channel.ChannelOperationsHandler.flush(ChannelOperationsHandler.java:194) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:802) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:814) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:794) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:837) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:1071) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:300) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at reactor.netty.http.server.HttpServerOperations.onOutboundComplete(HttpServerOperations.java:487) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at reactor.netty.channel.ChannelOperations.onComplete(ChannelOperations.java:191) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onComplete(FluxOnAssembly.java:383) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onComplete(MonoPeekTerminal.java:321) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onComplete(FluxOnAssembly.java:383) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.FluxPeekFuseable$PeekFuseableConditionalSubscriber.onComplete(FluxPeekFuseable.java:578) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onComplete(FluxOnAssembly.java:383) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.Operators$MonoSubscriber.onComplete(Operators.java:1516) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoIgnoreThen$ThenAcceptInner.onComplete(MonoIgnoreThen.java:314) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onComplete(FluxOnAssembly.java:383) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.Operators.complete(Operators.java:131) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoEmpty.subscribe(MonoEmpty.java:45) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:153) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:71) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoPeekFuseable.subscribe(MonoPeekFuseable.java:70) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:71) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoPeekTerminal.subscribe(MonoPeekTerminal.java:61) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) [reactor-core-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at reactor.netty.http.server.HttpServerHandle.onStateChange(HttpServerHandle.java:64) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at reactor.netty.tcp.TcpServerBind$ChildObserver.onStateChange(TcpServerBind.java:226) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:434) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:141) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:159) [reactor-netty-0.8.3.RELEASE.jar:0.8.3.RELEASE]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:323) [netty-codec-4.1.31.Final.jar:4.1.31.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:297) [netty-codec-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1434) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:965) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:648) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:583) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:500) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:462) [netty-transport-4.1.31.Final.jar:4.1.31.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:897) [netty-common-4.1.31.Final.jar:4.1.31.Final]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_192]
2018-12-10 21:41:17.013 DEBUG 31340 --- [ctor-http-nio-2] r.n.channel.ChannelOperationsHandler : [id: 0x7cc865b4, L:/0:0:0:0:0:0:0:1:8080 - R:/0:0:0:0:0:0:0:1:52638] No ChannelOperation attached. Dropping: EmptyLastHttpContent
反应堆的调试模式没有被激活。
所以我想知道如何在 spring webflux 中调试？或者有什么方法可以帮助我们快速找到代码中的错误？
【问题讨论】：
【参考方案1】：在 reactor 中，Hooks.onOperatorDebug() 检测 Reactor 运算符以在执行期间收集有关当前堆栈的更多信息。这有性能成本，不应该在生产中完成。这是一个静态调用，每次 JVM 执行只需执行一次，因此无需为每个控制器调用重复它。使用 Spring Boot，如果您对类路径具有 spring-boot-devtools 依赖项，这将自动为您完成。
从 Spring Boot 2.1 开始，您可以通过setting to DEBUG the web logging group，所以logging.level.web=debug 获得更好的 web 相关操作日志。这将记录有关 Web 请求处理的有用信息。
在您的情况下，您似乎也缺少有关 Reactor 管道执行的信息。在这种情况下，您应该在您的管道中add log() operators 以了解哪些信号正在通过您的管道。
在这个特定的代码 sn-p 中，我看到了几件事：
String a 方法参数似乎很奇怪，因为它没有与从传入请求中获取数据的注释耦合，例如 @RequestParam
Mono.zipWith(Mono) 运算符在这里没有意义；结果将始终是带有IllegalArgumentException 的错误信号。因此，预计 Spring Boot 错误处理会处理该异常并呈现 HTML 错误页面
【讨论】：
这里的性能成本有多糟糕？如果没有这个，您似乎无法追踪程序中发生的事情。以上是关于如何在 webflux 中调试？的主要内容，如果未能解决你的问题，请参考以下文章
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