最近重构项目的时候，用到了spring-boot-admin来搭建一个应用监控服务，但是启动的时候报了一个错：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'adminHandlerMapping' defined in class path resource [de/codecentric/boot/admin/server/config/AdminServerWebConfiguration$ServletRestApiConfirguation.class]: Invocation of init method failed; nested exception is java.lang.StackOverflowError at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1803) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:595) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:879) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878) ~[spring-context-5.2.0.RELEASE.jar:5.2.0.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.2.0.RELEASE.jar:5.2.0.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.2.0.RELEASE.jar:2.2.0.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.2.0.RELEASE.jar:2.2.0.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.2.0.RELEASE.jar:2.2.0.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.2.0.RELEASE.jar:2.2.0.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.0.RELEASE.jar:2.2.0.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.0.RELEASE.jar:2.2.0.RELEASE] at com.cloud.basic.admin.AdminApplication.main(AdminApplication.java:16) [classes/:na] Caused by: java.lang.StackOverflowError: null at de.codecentric.boot.admin.server.web.servlet.AdminControllerHandlerMapping.registerHandlerMethod(AdminControllerHandlerMapping.java:44) ~[spring-boot-admin-server-2.1.6.jar:2.1.6] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.registerHandlerMethod(RequestMappingHandlerMapping.java:67) ~[spring-webmvc-5.2.0.RELEASE.jar:5.2.0.RELEASE] at de.codecentric.boot.admin.server.web.servlet.AdminControllerHandlerMapping.registerHandlerMethod(AdminControllerHandlerMapping.java:44) ~[spring-boot-admin-server-2.1.6.jar:2.1.6] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.registerHandlerMethod(RequestMappingHandlerMapping.java:67) ~[spring-webmvc-5.2.0.RELEASE.jar:5.2.0.RELEASE] at de.codecentric.boot.admin.server.web.servlet.AdminControllerHandlerMapping.registerHandlerMethod(AdminControllerHandlerMapping.java:44) ~[spring-boot-admin-server-2.1.6.jar:2.1.6] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.registerHandlerMethod(RequestMappingHandlerMapping.java:67) ~[spring-webmvc-5.2.0.RELEASE.jar:5.2.0.RELEASE]查了下资料，一般出现这个情况是由于版本不对，而且大都是2.1.6版本会出现这个问题。把版本换了就好了。
报错版本：
<dependency> <groupId>de.codecentric</groupId> <artifactId>spring-boot-admin-server</artifactId> <version>2.1.6</version> </dependency>正常版本：
<dependency> <groupId>de.codecentric</groupId> <artifactId>spring-boot-admin-server</artifactId> <version>2.1.6</version> </dependency>启动成功：
访问：http://localhost:8401/login 熟悉的页面出现了
