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下文是从stackoverflow上面找到的对这两者的解释：

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.

原文地址为:What’s the difference between EnableEurekaClient and EnableDiscoveryClient?

意思也就是spring cloud中discovery service有许多种实现（eureka、consul、zookeeper等等），@EnableDiscoveryClient基于spring-cloud-commons, @EnableEurekaClient基于spring-cloud-netflix。

其实用更简单的话来说，就是如果选用的注册中心是eureka，那么就推荐@EnableEurekaClient，如果是其他的注册中心，那么推荐使用@EnableDiscoveryClient。

1、@EnableEurekaClient

我们具体的对@EnableEurekaClient的源码看一下，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，可以说基本就是EnableEurekaClient有@EnableDiscoveryClient的功能，另外上面的注释中提到，其实**@EnableEurekaClient**z注解就是一种方便使用eureka的注解而已，可以说使用其他的注册中心后，都可以使用@EnableDiscoveryClient注解，但是使用@EnableEurekaClient的情景，就是在服务采用eureka作为注册中心的时候，使用场景较为单一。

Spring boot 2.0之后，@EnableEurekaClient已经不是由@EnableDiscoveryClient实现的了。

/**      * 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      public @interface EnableEurekaClient {            }

2、@EurekaDiscoveryClient

/** * Annotation to enable a DiscoveryClient implementation. * @author Spencer Gibb */ @Target(ElementType.TYPE) @Retention(RetentionPolicy.RUNTIME) @Documented @Inherited @Import(EnableDiscoveryClientImportSelector.class) public @interface EnableDiscoveryClient { }

注解@EnableDiscoveryClient上有注解@Import(EnableDiscoveryClientImportSelector.class)修饰，@Import不仅可以单独导入一个配置，另外也可以导入普通的java类，并将其声明为一个bean。此处导入EnableDiscoveryClientImportSelector.class后，加载我们用到的bean，EnableDiscoveryClientImportSelector.class源码如下：

/** * @author Spencer Gibb */ @Order(Ordered.LOWEST_PRECEDENCE - 100) public class EnableDiscoveryClientImportSelector extends SpringFactoryImportSelector
   
     {     @Override protected boolean isEnabled() {         return new RelaxedPropertyResolver(        getEnvironment()).getProperty( "spring.cloud.discovery.enabled", Boolean.class, Boolean.TRUE);     }       @Override protected boolean hasDefaultFactory() {         return true;     } }
   

这个类中有一个覆盖父类的方法isEnabled(),返回默认为true，那么说明只要是引入了EnableDiscoveryClientImportSelector类，spring.cloud.discovery.enabled就处于enable状态。

EnableDiscoveryClientImportSelector继承了类SpringFactoryImportSelector。

在关键的方法selectImports中:

// Find all possible auto configuration classes, filtering duplicates List
   
     factories = new ArrayList<>(    new LinkedHashSet<>(SpringFactoriesLoader .loadFactoryNames(this.annotationClass, this.beanClassLoader)));
   

根据这一步来找到configuration class,这里的SpringFactoriesLoader.loadFactoryNames就是根据配置文件来load class，转到SpringFactoriesLoader.loadFactoryNames。

。。。。。

原文:

转载地址：https://blog.csdn.net/MyronCham/article/details/84312928 如侵犯您的版权，请留言回复原文章的地址，我们会给您删除此文章，给您带来不便请您谅解！