环境：intellij idea 2018.1.8 + jdk1.8 + spring boot 2.2.0.RELEASE

参考：https://www.cnblogs.com/grasp/p/9258811.html（侵删）

我们使用idea自动生成，最终在运行eureka client的时候会报错：

java.lang.NoClassDefFoundError: org/springframework/boot/actuate/health/HealthAggregator
	at java.lang.Class.getDeclaredConstructors0(Native Method) ~[na:1.8.0_171]
	at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671) ~[na:1.8.0_171]
	at java.lang.Class.getDeclaredConstructors(Class.java:2020) ~[na:1.8.0_171]
	at org.springframework.boot.context.properties.ConfigurationPropertiesBean$BindMethod.findBindConstructor(ConfigurationPropertiesBean.java:318) ~[spring-boot-2.2.0.RELEASE.jar:2.2.0.RELEASE]
	at org.springframework.boot.context.properties.ConfigurationPropertiesBean$BindMethod.forClass(ConfigurationPropertiesBean.java:300) ~[spring-boot-2.2.0.RELEASE.jar:2.2.0.RELEASE]
	at org.springframework.boot.context.properties.ConfigurationPropertiesBeanDefinitionValidator.validate(ConfigurationPropertiesBeanDefinitionValidator.java:57) ~[spring-boot-2.2.0.RELEASE.jar:2.2.0.RELEASE]
	at org.springframework.boot.context.properties.ConfigurationPropertiesBeanDefinitionValidator.postProcessBeanFactory(ConfigurationPropertiesBeanDefinitionValidator.java:45) ~[spring-boot-2.2.0.RELEASE.jar:2.2.0.RELEASE]
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:286) ~[spring-context-5.2.0.RELEASE.jar:5.2.0.RELEASE]
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:174) ~[spring-context-5.2.0.RELEASE.jar:5.2.0.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:706) ~[spring-context-5.2.0.RELEASE.jar:5.2.0.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:532) ~[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.czc.eurekaclient.EurekaClientApplication.main(EurekaClientApplication.java:12) [classes/:na]
Caused by: java.lang.ClassNotFoundException: org.springframework.boot.actuate.health.HealthAggregator
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_171]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_171]
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349) ~[na:1.8.0_171]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_171]
	... 18 common frames omitted

也就是找不到HealthAggregator这个类。

解决：

在eureka-client模块的pom.xml中加入依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>