Spring boot 2.0.3 RELEASE 配置报错 

java.lang.NoClassDefFoundError: org/springframework/boot/bind/RelaxedPropertyResolver
at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.getExcludeAutoConfigurationsProperty(AutoConfigurationImportSelector.java:215)
at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.getExclusions(AutoConfigurationImportSelector.java:209)
at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.selectImports(AutoConfigurationImportSelector.java:99)
at org.springframework.context.annotation.ConfigurationClassParser$DefaultDeferredImportSelectorGroup.process(ConfigurationClassParser.java:844)
at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGrouping.getImports(ConfigurationClassParser.java:830)
at org.springframework.context.annotation.ConfigurationClassParser.processDeferredImportSelectors(ConfigurationClassParser.java:563)
at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:188)
at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:316)
at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:233)
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:273)
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:93)
at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:694)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:532)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:327)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243)
at cn.seedid.health.AdminApplication.main(AdminApplication.java:15)
Caused by: java.lang.ClassNotFoundException: org.springframework.boot.bind.RelaxedPropertyResolver
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

... 20 common frames omitted

发现在我的pom.xml文件中，引用了

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.10</version>
</dependency>

而这个引用中默认的spring.boot 版本是1.5.12，这个版本中引入了RelaxedPropertyResolver，所有找不到，报错了。因此在需要pom.xml文件中，引入

<parent>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-parent</artifactId>
   <version>2.0.3.RELEASE</version>
</parent>

覆盖掉

druid-spring-boot-starter中的spring.boot版本， 错误消失！

原文地址：https://blog.csdn.net/jackhuclan/article/details/81039960