场景：

依赖：

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>


<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<spring-cloud.version>Edgware.RELEASE</spring-cloud.version>
</properties>


<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka-server</artifactId>
</dependency>


<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>


<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>

其实去掉@EnableEurekaServer 注解后，你会发现一切能正常启动。

加上后出现错误：

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2017-12-20 15:45:47.492 ERROR 23936 --- [           main] o.s.boot.SpringApplication               : Application startup failed


org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServletContainerException:Unable to start embedded Tomcat
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:537) ~[spring-context-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at com.doudou.EurekaDoudouApplication.main(EurekaDoudouApplication.java:12) [classes/:na]
Caused by: org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:123) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.<init>(TomcatEmbeddedServletContainer.java:84) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:554) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:179) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:164) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:134) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
... 8 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'jerseyFilterRegistration' defined in class path resource [org/springframework/cloud/netflix/eureka/server/EurekaServerAutoConfiguration.class]: Unsatisfied dependency expressed through method 'jerseyFilterRegistration' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jerseyApplication' defined in class path resource [org/springframework/cloud/netflix/eureka/server/EurekaServerAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.ws.rs.core.Application]: Factory method 'jerseyApplication' threw exception; nested exception is java.lang.NoClassDefFoundError: com/sun/jersey/api/core/DefaultResourceConfig
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:467) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.getOrderedBeansOfType(ServletContextInitializerBeans.java:234) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.getOrderedBeansOfType(ServletContextInitializerBeans.java:215) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addServletContextInitializerBeans(ServletContextInitializerBeans.java:91) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.<init>(ServletContextInitializerBeans.java:79) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.getServletContextInitializerBeans(EmbeddedWebApplicationContext.java:241) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.selfInitialize(EmbeddedWebApplicationContext.java:228) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.access$000(EmbeddedWebApplicationContext.java:89) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext$1.onStartup(EmbeddedWebApplicationContext.java:213) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.boot.context.embedded.tomcat.TomcatStarter.onStartup(TomcatStarter.java:55) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5196) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1419) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1409) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_141]

解决方法：是因为本地maven仓库已经有冲突，只需在本地新建一个maven仓库，重新maven update，导入依赖就行。