1,错误信息

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': FactoryBean threw exception on object 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$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:643) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1415) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:608) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:923) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:588) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144) ~[spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:767) [spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:426) [spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:326) [spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1309) [spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1298) [spring-boot-2.4.1.jar:2.4.1]
    at com.atguigu.gulimall.member.GulimallMemberApplication.main(GulimallMemberApplication.java:14) [classes/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.atguigu.gulimall.member.feign.CouponFeignService': FactoryBean threw exception on object 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.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:176) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.getObjectFromFactoryBean(FactoryBeanRegistrySupport.java:101) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getObjectForBeanInstance(AbstractBeanFactory.java:1879) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getObjectForBeanInstance(AbstractAutowireCapableBeanFactory.java:1268) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:267) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:1592) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1549) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1330) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ~[spring-beans-5.3.2.jar:5.3.2]
    ... 20 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:309) ~[spring-cloud-openfeign-core-3.0.0.jar:3.0.0]
    at org.springframework.cloud.openfeign.FeignClientFactoryBean.getTarget(FeignClientFactoryBean.java:335) ~[spring-cloud-openfeign-core-3.0.0.jar:3.0.0]
    at org.springframework.cloud.openfeign.FeignClientFactoryBean.getObject(FeignClientFactoryBean.java:315) ~[spring-cloud-openfeign-core-3.0.0.jar:3.0.0]
    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:169) ~[spring-beans-5.3.2.jar:5.3.2]
    ... 31 common frames omitted

2，解决方案

在pom.xml 中引入

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

3，错误原因

https://blog.csdn.net/weixin_43556636/article/details/110653989