org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'memberController': Unsatisfied dependency expressed through field 'couponFeignService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.atguigu.gulimall.member.feign.CouponFeignService': Unexpected exception during bean creation; nested exception is java.lang.IllegalStateException: No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-loadbalancer?
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor\(AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:660) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor\)AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ~[spring-beans-5.3.6.jar:5.3.6]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.6.jar:5.3.6]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.6.jar:5.3.6]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1413) ~[spring-beans-5.3.6.jar:5.3.6]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601) ~[spring-beans-5.3.6.jar:5.3.6]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.6.jar:5.3.6]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean\(0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.6.jar:5.3.6] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.6.jar:5.3.6] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144) ~[spring-boot-2.4.5.jar:2.4.5] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:782) [spring-boot-2.4.5.jar:2.4.5] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:774) [spring-boot-2.4.5.jar:2.4.5] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:439) [spring-boot-2.4.5.jar:2.4.5] at org.springframework.boot.SpringApplication.run(SpringApplication.java:339) [spring-boot-2.4.5.jar:2.4.5] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1340) [spring-boot-2.4.5.jar:2.4.5] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1329) [spring-boot-2.4.5.jar:2.4.5] at com.atguigu.gulimall.member.GulimallMemberApplication.main(GulimallMemberApplication.java:28) [classes/:na] Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.atguigu.gulimall.member.feign.CouponFeignService': Unexpected exception during bean creation; nested exception is java.lang.IllegalStateException: No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-loadbalancer? at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:537) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda\)doGetBean\(0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1380) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300) ~[spring-beans-5.3.6.jar:5.3.6] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor\)AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:657) ~[spring-beans-5.3.6.jar:5.3.6]
... 21 common frames omitted
Caused by: java.lang.IllegalStateException: No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-loadbalancer?
at org.springframework.cloud.openfeign.FeignClientFactoryBean.loadBalance(FeignClientFactoryBean.java:333) ~[spring-cloud-openfeign-core-3.0.2.jar:3.0.2]
at org.springframework.cloud.openfeign.FeignClientFactoryBean.getTarget(FeignClientFactoryBean.java:360) ~[spring-cloud-openfeign-core-3.0.2.jar:3.0.2]
at org.springframework.cloud.openfeign.FeignClientFactoryBean.getObject(FeignClientFactoryBean.java:339) ~[spring-cloud-openfeign-core-3.0.2.jar:3.0.2]
at org.springframework.cloud.openfeign.FeignClientsRegistrar.lambda$registerFeignClient$0(FeignClientsRegistrar.java:230) ~[spring-cloud-openfeign-core-3.0.2.jar:3.0.2]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.obtainFromSupplier(AbstractAutowireCapableBeanFactory.java:1231) ~[spring-beans-5.3.6.jar:5.3.6]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1173) ~[spring-beans-5.3.6.jar:5.3.6]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:564) ~[spring-beans-5.3.6.jar:5.3.6]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.6.jar:5.3.6]
... 29 common frames omitted

Process finished with exit code 1

关键错误在这里：

SpringCloud Feign在Hoxton.M2 RELEASED版本之后不再使用Ribbon而是使用spring-cloud-loadbalancer，所以不引入spring-cloud-loadbalancer会报错

解决方法：

加入以下依赖

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

最后成功启动！