在使用服務發現的時候有兩種注解，
一種為@EnableDiscoveryClient,
一種為@EnableEurekaClient,
用法上基本一致，下文是從stackoverflow上面找到的對這兩者的解釋：
There are multiple implementations of "Discovery Service" (eureka, consul, zookeeper).
@EnableDiscoveryClient lives in spring-cloud-commons and picks the implementation on the classpath.
@EnableEurekaClient lives in spring-cloud-netflix and only works for eureka. If eureka is on your classpath, they are effectively the same.
意思也就是spring cloud中discovery service有許多種實現（eureka、consul、zookeeper等等）
@EnableDiscoveryClient基於spring-cloud-commons；而 @EnableEurekaClient基於spring-cloud-netflix
對@EnableEurekaClient的源碼如下：
/** * Convenience annotation for clients to enable Eureka discovery configuration * (specifically). Use this (optionally) in case you want discovery and know for sure that * it is Eureka you want. All it does is turn on discovery and let the autoconfiguration * find the eureka classes if they are available (i.e. you need Eureka on the classpath as * well). * * @author Dave Syer * @author Spencer Gibb */ @Target(ElementType.TYPE) @Retention(RetentionPolicy.RUNTIME) @Documented @Inherited @EnableDiscoveryClient public @interface EnableEurekaClient { }
注解@EnableEurekaClient上有@EnableDiscoveryClient注解，可以說基本就是EnableEurekaClient有@EnableDiscoveryClient的功能，另外上面的注釋中提到，其實@EnableEurekaClient注解就是一種方便使用eureka的注解而已，可以說使用其他的注冊中心后，都可以使用@EnableDiscoveryClient注解，
但是使用@EnableEurekaClient的情景，就是在服務采用eureka作為注冊中心的時候，使用場景較為單一。