1.引起原因，springboot parent版本为
报错如下：
org.springframework.beans.factory.support.BeanDefinitionOverrideException: Invalid bean definition with name 'scopedTarget.oauth2ClientContext' defined in class path resource [org/springframework/boot/autoconfigure/security/oauth2/client/OAuth2RestOperationsConfiguration$SessionScopedConfiguration$ClientContextConfiguration.class]: Cannot register bean definition [Root bean: class [null]; scope=session; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=false; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2RestOperationsConfiguration$SessionScopedConfiguration$ClientContextConfiguration; factoryMethodName=oauth2ClientContext; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/security/oauth2/client/OAuth2RestOperationsConfiguration$SessionScopedConfiguration$ClientContextConfiguration.class]] for bean 'scopedTarget.oauth2ClientContext': There is already [Root bean: class [null]; scope=session; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=false; primary=false; factoryBeanName=org.springframework.security.oauth2.config.annotation.web.configuration.OAuth2ClientConfiguration$OAuth2ClientContextConfiguration; factoryMethodName=oauth2ClientContext; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/security/oauth2/config/annotation/web/configuration/OAuth2ClientConfiguration$OAuth2ClientContextConfiguration.class]] bound.
at org.springframework.beans.factory.support.DefaultListableBeanFactory.registerBeanDefinition(DefaultListableBeanFactory.java:894) ~[spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.aop.scope.ScopedProxyUtils.createScopedProxy(ScopedProxyUtils.java:85) ~[spring-aop-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ScopedProxyCreator.createScopedProxy(ScopedProxyCreator.java:40) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForBeanMethod(ConfigurationClassBeanDefinitionReader.java:263) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:141) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(ConfigurationClassBeanDefinitionReader.java:117) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:327) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:232) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:275) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:95) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:691) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:528) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at com.huaxiang.ResourceServiceApplication.main(ResourceServiceApplication.java:14) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_192]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_192]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_192]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_192]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.1.2.RELEASE.jar:2.1.2.RELEASE]
2019-02-20 10:45:24.392 ERROR 2404 --- [ restartedMain] o.s.b.d.LoggingFailureAnalysisReporter :
***************************
APPLICATION FAILED TO START
***************************
Description:
The bean 'scopedTarget.oauth2ClientContext', defined in class path resource [org/springframework/boot/autoconfigure/security/oauth2/client/OAuth2RestOperationsConfiguration$SessionScopedConfiguration$ClientContextConfiguration.class], could not be registered. A bean with that name has already been defined in class path resource [org/springframework/security/oauth2/config/annotation/web/configuration/OAuth2ClientConfiguration$OAuth2ClientContextConfiguration.class] and overriding is disabled.
Action:
Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true
2.解决方案
2.1 上面的提示已经明确告诉设置 spring.main.allow-bean-definition-overriding = true,默认是false
如我的解决方法，在application.yml添加
2.2 降低springboot parent版本，改成2.0.3.RELEASE