org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'xxxController': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Circular placeholder reference 'spring.datasource.driver-class-name' in property definitions
at
org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:380) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1411) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:845) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:743) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:390) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1214) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1203) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at com.example.test_env.TestEnvApplication.main(TestEnvApplication.java:10) [classes/:na]
Caused by: java.lang.IllegalArgumentException: Circular placeholder reference 'test.testenv:127.0.0.1' in property definitions
at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:145) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:166) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:237) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:211) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.core.env.AbstractPropertyResolver.resolveNestedPlaceholders(AbstractPropertyResolver.java:228) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.core.env.PropertySourcesPropertyResolver.getProperty(PropertySourcesPropertyResolver.java:88) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.core.env.PropertySourcesPropertyResolver.getProperty(PropertySourcesPropertyResolver.java:62) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.core.env.AbstractEnvironment.getProperty(AbstractEnvironment.java:539) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.context.support.PropertySourcesPlaceholderConfigurer$1.getProperty(PropertySourcesPlaceholderConfigurer.java:137) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.context.support.PropertySourcesPlaceholderConfigurer$1.getProperty(PropertySourcesPlaceholderConfigurer.java:133) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.core.env.PropertySourcesPropertyResolver.getProperty(PropertySourcesPropertyResolver.java:85) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.core.env.PropertySourcesPropertyResolver.getPropertyAsRawString(PropertySourcesPropertyResolver.java:74) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:151) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:237) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:211) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties$0(PropertySourcesPlaceholderConfigurer.java:175) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:851) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1192) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1171) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
... 17 common frames omitted
spring: datasource: driver-class-name: ${spring.datasource.driver-class-name}
比如这段 application.yml 配置，虽然这里是 yml 是冒号，这里 ${} 里面是点号，但是这样会产生循环依赖，所以这里跟 Nacos 上需要改下配置变量命名，命名不要一样即可。
spring: datasource: driver-class-name: ${nacos.spring.datasource.driver-class-name}
这样就对了！！！
