启动Spring Boot项目时报错：The dependencies of some of the beans in the application context form a cycle

更详细错误内容如下：

2020-08-03 12:56:35.903  INFO 3551 --- [ost-startStop-1] c.n.c.sources.URLConfigurationSource     : To enable URLs as dynamic configuration sources, define System property archaius.configurationSource.additionalUrls or make config.properties available on classpath.
2020-08-03 12:56:35.910  INFO 3551 --- [ost-startStop-1] c.netflix.config.DynamicPropertyFactory  : DynamicPropertyFactory is initialized with configuration sources: com.netflix.config.ConcurrentCompositeConfiguration@53cd7837
2020-08-03 12:56:36.192 ERROR 3551 --- [ost-startStop-1] o.s.b.web.embedded.tomcat.TomcatStarter  : Error starting Tomcat context. Exception: org.springframework.beans.factory.BeanCreationException. Message: Error creating bean with name 'servletEndpointRegistrar' defined in class path resource [org/springframework/boot/actuate/autoconfigure/endpoint/web/ServletEndpointManagementContextConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.actuate.endpoint.web.ServletEndpointRegistrar]: Factory method 'servletEndpointRegistrar' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'healthEndpoint' defined in class path resource [org/springframework/boot/actuate/autoconfigure/health/HealthEndpointConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.actuate.health.HealthEndpoint]: Factory method 'healthEndpoint' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.actuate.autoconfigure.jdbc.DataSourceHealthIndicatorAutoConfiguration': Bean instantiation via constructor failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.actuate.autoconfigure.jdbc.DataSourceHealthIndicatorAutoConfiguration$$EnhancerBySpringCGLIB$$1b4253c4]: Constructor threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource': Post-processing of FactoryBean's singleton object failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource': Post-processing of FactoryBean's singleton object failed; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'scopedTarget.dataSource': Requested bean is currently in creation: Is there an unresolvable circular reference?
2020-08-03 12:56:36.208  INFO 3551 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2020-08-03 12:56:36.212  WARN 3551 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
2020-08-03 12:56:36.221  INFO 3551 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-08-03 12:56:36.225 ERROR 3551 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

The dependencies of some of the beans in the application context form a cycle:

   servletEndpointRegistrar defined in class path resource [org/springframework/boot/actuate/autoconfigure/endpoint/web/ServletEndpointManagementContextConfiguration.class]
      ↓
   healthEndpoint defined in class path resource [org/springframework/boot/actuate/autoconfigure/health/HealthEndpointConfiguration.class]
      ↓
   org.springframework.boot.actuate.autoconfigure.jdbc.DataSourceHealthIndicatorAutoConfiguration
┌─────┐
|  dataSource
↑     ↓
|  scopedTarget.dataSource defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]
↑     ↓
|  org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker
└─────┘


Disconnected from the target VM, address: '127.0.0.1:53613', transport: 'socket'

Process finished with exit code 1

从异常信息可以看出，这是循环依赖问题。这种通常会出现在两个类注入Bean时互相使用了构造函数注入对方。Spring IoC容器在运行时检测到此循环引用就会报错。

异常信息中没有任何业务代码的错误提示，而且报的是boot datasource循环依赖，于是怀疑库本身有bug，果不其然，升级完Spring Boot版本后，异常就消失了。

解决办法就是升级Spring Boot版本：

2.0.1.RELEASE-->2.0.2.RELEASE 或 以上版本

参考资料：https://github.com/spring-projects/spring-boot/issues/13406