Spring 项目版本：
org.springframework.boot
spring-boot-starter-parent
2.4.2
org.springframework.cloud
spring-cloud-dependencies
2020.0.1
pom
import
com.alibaba.cloud
spring-cloud-alibaba-dependencies
2021.1
pom
import
feign等pom依赖
com.alibaba.cloud
spring-cloud-starter-alibaba-nacos-discovery
org.springframework.cloud
spring-cloud-starter-loadbalancer
org.springframework.cloud
spring-cloud-starter-openfeign
启动报错：
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-10-25 21:37:31.797 ERROR 48163 --- [ main] o.s.boot.SpringApplication : Application run failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'feignController': Unsatisfied dependency expressed through field 'feignApiExample'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'feignEncoder' defined in org.springframework.cloud.openfeign.FeignClientsConfiguration: Unexpected exception during bean creation; nested exception is java.lang.NoClassDefFoundError: feign/form/multipart/AbstractWriter
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:643) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1415) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:608) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:923) ~[spring-context-5.3.3.jar:5.3.3]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:588) ~[spring-context-5.3.3.jar:5.3.3]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144) ~[spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:767) [spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:426) [spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:326) [spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1311) [spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1300) [spring-boot-2.4.2.jar:2.4.2]
at com.haizhi.mdc.datacenter.example.service.ExampleApplication.main(ExampleApplication.java:16) [classes/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'feignEncoder' defined in org.springframework.cloud.openfeign.FeignClientsConfiguration: Unexpected exception during bean creation; nested exception is java.lang.NoClassDefFoundError: feign/form/multipart/AbstractWriter
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:544) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:923) ~[spring-context-5.3.3.jar:5.3.3]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:588) ~[spring-context-5.3.3.jar:5.3.3]
at org.springframework.cloud.context.named.NamedContextFactory.createContext(NamedContextFactory.java:133) ~[spring-cloud-context-3.0.1.jar:3.0.1]
at org.springframework.cloud.context.named.NamedContextFactory.getContext(NamedContextFactory.java:101) ~[spring-cloud-context-3.0.1.jar:3.0.1]
at org.springframework.cloud.context.named.NamedContextFactory.getInstance(NamedContextFactory.java:142) ~[spring-cloud-context-3.0.1.jar:3.0.1]
at org.springframework.cloud.openfeign.FeignClientFactoryBean.get(FeignClientFactoryBean.java:279) ~[spring-cloud-openfeign-core-3.0.1.jar:3.0.1]
at org.springframework.cloud.openfeign.FeignClientFactoryBean.feign(FeignClientFactoryBean.java:105) ~[spring-cloud-openfeign-core-3.0.1.jar:3.0.1]
at org.springframework.cloud.openfeign.FeignClientFactoryBean.getTarget(FeignClientFactoryBean.java:333) ~[spring-cloud-openfeign-core-3.0.1.jar:3.0.1]
at org.springframework.cloud.openfeign.FeignClientFactoryBean.getObject(FeignClientFactoryBean.java:322) ~[spring-cloud-openfeign-core-3.0.1.jar:3.0.1]
at org.springframework.cloud.openfeign.FeignClientsRegistrar.lambda$registerFeignClient$0(FeignClientsRegistrar.java:224) ~[spring-cloud-openfeign-core-3.0.1.jar:3.0.1]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.obtainFromSupplier(AbstractAutowireCapableBeanFactory.java:1233) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1175) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:571) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1380) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ~[spring-beans-5.3.3.jar:5.3.3]
... 20 common frames omitted
Caused by: java.lang.NoClassDefFoundError: feign/form/multipart/AbstractWriter
at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_261]
at java.lang.ClassLoader.defineClass(ClassLoader.java:756) ~[na:1.8.0_261]
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[na:1.8.0_261]
at java.net.URLClassLoader.defineClass(URLClassLoader.java:468) ~[na:1.8.0_261]
at java.net.URLClassLoader.access$100(URLClassLoader.java:74) ~[na:1.8.0_261]
at java.net.URLClassLoader$1.run(URLClassLoader.java:369) ~[na:1.8.0_261]
at java.net.URLClassLoader$1.run(URLClassLoader.java:363) ~[na:1.8.0_261]
at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_261]
at java.net.URLClassLoader.findClass(URLClassLoader.java:362) ~[na:1.8.0_261]
at java.lang.ClassLoader.loadClass(ClassLoader.java:418) ~[na:1.8.0_261]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355) ~[na:1.8.0_261]
at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[na:1.8.0_261]
at java.lang.Class.forName0(Native Method) ~[na:1.8.0_261]
at java.lang.Class.forName(Class.java:348) ~[na:1.8.0_261]
at sun.reflect.generics.factory.CoreReflectionFactory.makeNamedType(CoreReflectionFactory.java:114) ~[na:1.8.0_261]
at sun.reflect.generics.visitor.Reifier.visitClassTypeSignature(Reifier.java:125) ~[na:1.8.0_261]
at sun.reflect.generics.tree.ClassTypeSignature.accept(ClassTypeSignature.java:49) ~[na:1.8.0_261]
at sun.reflect.generics.visitor.Reifier.reifyTypeArguments(Reifier.java:68) ~[na:1.8.0_261]
at sun.reflect.generics.visitor.Reifier.visitClassTypeSignature(Reifier.java:138) ~[na:1.8.0_261]
at sun.reflect.generics.tree.ClassTypeSignature.accept(ClassTypeSignature.java:49) ~[na:1.8.0_261]
at sun.reflect.generics.repository.ConstructorRepository.getParameterTypes(ConstructorRepository.java:94) ~[na:1.8.0_261]
at java.lang.reflect.Executable.getGenericParameterTypes(Executable.java:283) ~[na:1.8.0_261]
at java.lang.reflect.Method.getGenericParameterTypes(Method.java:283) ~[na:1.8.0_261]
at org.springframework.core.MethodParameter.getGenericParameterType(MethodParameter.java:513) ~[spring-core-5.3.3.jar:5.3.3]
at org.springframework.core.MethodParameter.getNestedParameterType(MethodParameter.java:553) ~[spring-core-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.config.DependencyDescriptor.getDependencyType(DependencyDescriptor.java:411) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.DefaultListableBeanFactory$DependencyObjectProvider.(DefaultListableBeanFactory.java:1969) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1291) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:887) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:541) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1336) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1179) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:571) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.3.jar:5.3.3]
... 47 common frames omitted
Caused by: java.lang.ClassNotFoundException: feign.form.multipart.AbstractWriter
at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[na:1.8.0_261]
at java.lang.ClassLoader.loadClass(ClassLoader.java:418) ~[na:1.8.0_261]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355) ~[na:1.8.0_261]
at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[na:1.8.0_261]
... 82 common frames omitted
发现是缺少包，pom增加feign-form后解决：
io.github.openfeign.form
feign-form
3.8.0