springcloud 添加 gateway 启动报错 Exception encountered during context initialization

报错 Exception encountered during context initialization"/>

springcloud 添加 gateway 启动报错 Exception encountered during context initialization

springcloud 添加 gateway 启动报错

**********************************************************Spring MVC found on classpath, which is incompatible with Spring Cloud Gateway at this time. Please remove spring-boot-starter-web dependency.**********************************************************15.366 WARN  o.s.b.w.s.c.AnnotationConfigServletWebServerApplicationContext:559  Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'gatewayConfigurationService' defined in class path resource [org/springframework/cloud/gateway/config/GatewayAutoConfiguration.class]: Unsatisfied dependency expressed through method 'gatewayConfigurationService' parameter 1; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.springframework.core.convert.ConversionService' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Qualifier(value=webFluxConversionService)}
15.369 INFO  o.a.c.core.StandardService    :173  Stopping service [Tomcat]
15.385 INFO  o.s.b.a.l.ConditionEvaluationReportLoggingListener:136  Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
15.521 ERROR o.s.boot.SpringApplication    :837  Application run failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'gatewayConfigurationService' defined in class path resource [org/springframework/cloud/gateway/config/GatewayAutoConfiguration.class]: Unsatisfied dependency expressed through method 'gatewayConfigurationService' parameter 1; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.springframework.core.convert.ConversionService' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Qualifier(value=webFluxConversionService)}at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:797)at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:538)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226)at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:893)at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:879)at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551)at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143)at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758)at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750)at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)at com.course.gateway.GatewayApplication.main(GatewayApplication.java:18)

原因 ：

<dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>

里面已经引入了

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

在pom文件或父项目的pom文件中找到重复引入，如下图：

此时启动报错
解决方式：删除多余的引入

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

删除后，启动成功

更深层次的原始是Gateway底层是webflux框架，在spring-cloud-starter-gateway中已经做了web初始化，springmvc再去初始化就会冲突，导致的报错