报错信息
java.lang.NoClassDefFoundError: org/springframework/cloud/context/named/NamedContextFactory$Specification
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
at java.net.URLClassLoader1. r u n ( U R L C l a s s L o a d e r . j a v a : 363 ) a t j a v a . s e c u r i t y . A c c e s s C o n t r o l l e r . d o P r i v i l e g e d ( N a t i v e M e t h o d ) a t j a v a . n e t . U R L C l a s s L o a d e r . f i n d C l a s s ( U R L C l a s s L o a d e r . j a v a : 362 ) a t j a v a . l a n g . C l a s s L o a d e r . l o a d C l a s s ( C l a s s L o a d e r . j a v a : 424 ) a t s u n . m i s c . L a u n c h e r 1.run(URLClassLoader.java:363) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:362) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher1.run(URLClassLoader.java:363)atjava.security.AccessController.doPrivileged(NativeMethod)atjava.net.URLClassLoader.findClass(URLClassLoader.java:362)atjava.lang.ClassLoader.loadClass(ClassLoader.java:424)atsun.misc.LauncherAppClassLoader.loadClass(Launcher.java:349)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.springframework.cloud.openfeign.FeignClientsRegistrar.registerClientConfiguration(FeignClientsRegistrar.java:351)
at org.springframework.cloud.openfeign.FeignClientsRegistrar.registerDefaultConfiguration(FeignClientsRegistrar.java:99)
at org.springframework.cloud.openfeign.FeignClientsRegistrar.registerBeanDefinitions(FeignClientsRegistrar.java:82)
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.lambda$loadBeanDefinitionsFromRegistrars1 ( C o n f i g u r a t i o n C l a s s B e a n D e f i n i t i o n R e a d e r . j a v a : 364 ) a t j a v a . u t i l . L i n k e d H a s h M a p . f o r E a c h ( L i n k e d H a s h M a p . j a v a : 684 ) a t o r g . s p r i n g f r a m e w o r k . c o n t e x t . a n n o t a t i o n . C o n f i g u r a t i o n C l a s s B e a n D e f i n i t i o n R e a d e r . l o a d B e a n D e f i n i t i o n s F r o m R e g i s t r a r s ( C o n f i g u r a t i o n C l a s s B e a n D e f i n i t i o n R e a d e r . j a v a : 363 ) a t o r g . s p r i n g f r a m e w o r k . c o n t e x t . a n n o t a t i o n . C o n f i g u r a t i o n C l a s s B e a n D e f i n i t i o n R e a d e r . l o a d B e a n D e f i n i t i o n s F o r C o n f i g u r a t i o n C l a s s ( C o n f i g u r a t i o n C l a s s B e a n D e f i n i t i o n R e a d e r . j a v a : 145 ) a t o r g . s p r i n g f r a m e w o r k . c o n t e x t . a n n o t a t i o n . C o n f i g u r a t i o n C l a s s B e a n D e f i n i t i o n R e a d e r . l o a d B e a n D e f i n i t i o n s ( C o n f i g u r a t i o n C l a s s B e a n D e f i n i t i o n R e a d e r . j a v a : 117 ) a t o r g . s p r i n g f r a m e w o r k . c o n t e x t . a n n o t a t i o n . C o n f i g u r a t i o n C l a s s P o s t P r o c e s s o r . p r o c e s s C o n f i g B e a n D e f i n i t i o n s ( C o n f i g u r a t i o n C l a s s P o s t P r o c e s s o r . j a v a : 327 ) a t o r g . s p r i n g f r a m e w o r k . c o n t e x t . a n n o t a t i o n . C o n f i g u r a t i o n C l a s s P o s t P r o c e s s o r . p o s t P r o c e s s B e a n D e f i n i t i o n R e g i s t r y ( C o n f i g u r a t i o n C l a s s P o s t P r o c e s s o r . j a v a : 232 ) a t o r g . s p r i n g f r a m e w o r k . c o n t e x t . s u p p o r t . P o s t P r o c e s s o r R e g i s t r a t i o n D e l e g a t e . i n v o k e B e a n D e f i n i t i o n R e g i s t r y P o s t P r o c e s s o r s ( P o s t P r o c e s s o r R e g i s t r a t i o n D e l e g a t e . j a v a : 275 ) a t o r g . s p r i n g f r a m e w o r k . c o n t e x t . s u p p o r t . P o s t P r o c e s s o r R e g i s t r a t i o n D e l e g a t e . i n v o k e B e a n F a c t o r y P o s t P r o c e s s o r s ( P o s t P r o c e s s o r R e g i s t r a t i o n D e l e g a t e . j a v a : 95 ) a t o r g . s p r i n g f r a m e w o r k . c o n t e x t . s u p p o r t . A b s t r a c t A p p l i c a t i o n C o n t e x t . i n v o k e B e a n F a c t o r y P o s t P r o c e s s o r s ( A b s t r a c t A p p l i c a t i o n C o n t e x t . j a v a : 705 ) a t o r g . s p r i n g f r a m e w o r k . c o n t e x t . s u p p o r t . A b s t r a c t A p p l i c a t i o n C o n t e x t . r e f r e s h ( A b s t r a c t A p p l i c a t i o n C o n t e x t . j a v a : 531 ) a t o r g . s p r i n g f r a m e w o r k . b o o t . w e b . s e r v l e t . c o n t e x t . S e r v l e t W e b S e r v e r A p p l i c a t i o n C o n t e x t . r e f r e s h ( S e r v l e t W e b S e r v e r A p p l i c a t i o n C o n t e x t . j a v a : 142 ) a t o r g . s p r i n g f r a m e w o r k . b o o t . S p r i n g A p p l i c a t i o n . r e f r e s h ( S p r i n g A p p l i c a t i o n . j a v a : 775 ) a t o r g . s p r i n g f r a m e w o r k . b o o t . S p r i n g A p p l i c a t i o n . r e f r e s h C o n t e x t ( S p r i n g A p p l i c a t i o n . j a v a : 397 ) a t o r g . s p r i n g f r a m e w o r k . b o o t . S p r i n g A p p l i c a t i o n . r u n ( S p r i n g A p p l i c a t i o n . j a v a : 316 ) a t o r g . s p r i n g f r a m e w o r k . b o o t . S p r i n g A p p l i c a t i o n . r u n ( S p r i n g A p p l i c a t i o n . j a v a : 1260 ) a t o r g . s p r i n g f r a m e w o r k . b o o t . S p r i n g A p p l i c a t i o n . r u n ( S p r i n g A p p l i c a t i o n . j a v a : 1248 ) a t c n . l u a n . L o a d B a l a n c e A p p l i c a t i o n . m a i n ( L o a d B a l a n c e A p p l i c a t i o n . j a v a : 22 ) C a u s e d b y : j a v a . l a n g . C l a s s N o t F o u n d E x c e p t i o n : o r g . s p r i n g f r a m e w o r k . c l o u d . c o n t e x t . n a m e d . N a m e d C o n t e x t F a c t o r y 1(ConfigurationClassBeanDefinitionReader.java:364) at java.util.LinkedHashMap.forEach(LinkedHashMap.java:684) at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsFromRegistrars(ConfigurationClassBeanDefinitionReader.java:363) at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:145) at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(ConfigurationClassBeanDefinitionReader.java:117) at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:327) at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:232) at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:275) at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:95) at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:705) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:531) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) at cn.luan.LoadBalanceApplication.main(LoadBalanceApplication.java:22) Caused by: java.lang.ClassNotFoundException: org.springframework.cloud.context.named.NamedContextFactory1(ConfigurationClassBeanDefinitionReader.java:364)atjava.util.LinkedHashMap.forEach(LinkedHashMap.java:684)atorg.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsFromRegistrars(ConfigurationClassBeanDefinitionReader.java:363)atorg.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:145)atorg.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(ConfigurationClassBeanDefinitionReader.java:117)atorg.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:327)atorg.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:232)atorg.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:275)atorg.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:95)atorg.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:705)atorg.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:531)atorg.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142)atorg.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)atorg.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)atorg.springframework.boot.SpringApplication.run(SpringApplication.java:316)atorg.springframework.boot.SpringApplication.run(SpringApplication.java:1260)atorg.springframework.boot.SpringApplication.run(SpringApplication.java:1248)atcn.luan.LoadBalanceApplication.main(LoadBalanceApplication.java:22)Causedby:java.lang.ClassNotFoundException:org.springframework.cloud.context.named.NamedContextFactorySpecification
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
… 33 common frames omitted
Process finished with exit code 1
原因：
在spring-cloud-netflix-core没有spring-cloud-context明确添加依赖项的情况下使用时，会NoClassDefFoundError抛出一个。因此，依赖项spring-cloud-context不能是可选的。
解决方法：添加对应的依赖：
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-context</artifactId>
<version>2.1.0.RELEASE</version>
</dependency>