由于Webflux，Spring Cloud Gateway启动错误？

Question

我有spring-cloud网关应用程序，但启动时失败。我怀疑这是依赖的问题。但是找不到解决方法。

我的POM

 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0     
                    http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<properties>
    <lombok.version>1.18.0</lombok.version>
    <ratelimitj-redis.version>0.6.0</ratelimitj-redis.version>
    <token-bucket.version>1.7</token-bucket.version>
    <spring-boot-starter-parent.version>2.1.7.RELEASE</spring-boot-starter-parent.version>
    <jjwt.version>0.9.1</jjwt.version>
</properties>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.2.RELEASE</version>
</parent>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Hoxton.RELEASE</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-gateway</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-gateway-webflux</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-contract-stub-runner</artifactId>
        <exclusions>
            <exclusion>
                <artifactId>spring-boot-starter-web</artifactId>
                <groupId>org.springframework.boot</groupId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>${lombok.version}</version>
    </dependency>
    <dependency>
        <groupId>es.moki.ratelimitj</groupId>
        <artifactId>ratelimitj-redis</artifactId>
        <version>${ratelimitj-redis.version}</version>
        <exclusions>
            <exclusion>
                <groupId>io.projectreactor</groupId>
                <artifactId>reactor-core</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.isomorphism</groupId>
        <artifactId>token-bucket</artifactId>
        <version>${token-bucket.version}</version>
    </dependency>
    <dependency>
        <groupId>org.keycloak</groupId>
        <artifactId>keycloak-admin-client</artifactId>
        <version>4.0.0.Beta1</version>
    </dependency>
    <dependency>
        <groupId>io.jsonwebtoken</groupId>
        <artifactId>jjwt</artifactId>
        <version>${jjwt.version}</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

启动时出现以下错误

 reactor.core.Exceptions$ErrorCallbackNotImplemented: java.lang.NullPointerException: The   mapper returned a null Publisher
Caused by: java.lang.NullPointerException: The mapper returned a null Publisher
at java.base/java.util.Objects.requireNonNull(Objects.java:246) ~[na:na]
at reactor.core.publisher.FluxFlatMap$FlatMapMain.onNext(FluxFlatMap.java:378) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxIterable$IterableSubscription.slowPath(FluxIterable.java:243) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxIterable$IterableSubscription.request(FluxIterable.java:201) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxFlatMap$FlatMapMain.onSubscribe(FluxFlatMap.java:363) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:139) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:63) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.InternalFluxOperator.subscribe(InternalFluxOperator.java:53) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:54) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.Flux.subscribe(Flux.java:8143) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.Flux.subscribeWith(Flux.java:8307) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.Flux.subscribe(Flux.java:8114) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.Flux.subscribe(Flux.java:8041) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.Flux.subscribe(Flux.java:7959) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter.lambda$onApplicationEvent$0(WeightCalculatorWebFilter.java:145) ~[spring-cloud-gateway-core-2.2.0.RELEASE.jar!/:2.2.0.RELEASE]
at org.springframework.beans.factory.ObjectProvider.ifAvailable(ObjectProvider.java:93) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter.onApplicationEvent(WeightCalculatorWebFilter.java:145) ~[spring-cloud-gateway-core-2.2.0.RELEASE.jar!/:2.2.0.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:403) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:360) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.cloud.gateway.route.RouteRefreshListener.reset(RouteRefreshListener.java:68) ~[spring-cloud-gateway-core-2.2.0.RELEASE.jar!/:2.2.0.RELEASE]
at org.springframework.cloud.gateway.route.RouteRefreshListener.onApplicationEvent(RouteRefreshListener.java:49) ~[spring-cloud-gateway-core-2.2.0.RELEASE.jar!/:2.2.0.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:403) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:360) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:897) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.finishRefresh(ReactiveWebServerApplicationContext.java:129) ~[spring-boot-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:553) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:66) ~[spring-boot-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
at com.sample.CloudGatewayApplication.main(CloudGatewayApplication.java:27) [classes!/:1.8-SNAPSHOT]
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:564) ~[na:na]
at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) [cloud-gateway-1.8-SNAPSHOT.jar:1.8-SNAPSHOT]
at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) [cloud-gateway-1.8-SNAPSHOT.jar:1.8-SNAPSHOT]
at org.springframework.boot.loader.Launcher.launch(Launcher.java:51) [cloud-gateway-1.8-SNAPSHOT.jar:1.8-SNAPSHOT]
at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:52) [cloud-gateway-1.8-SNAPSHOT.jar:1.8-SNAPSHOT]