环境：
Spring Cloud：Finchley.M8
Spring Boot：2.0.0.RELEASE
目录结构：
可以看到代码第13行的注释，我已经在@ComponentScan注解中添加了Exclude配置项，但是启动服务的时候还是报如下的错误：
2018-04-12 15:59:37.815 WARN 17828 --- [ main] o.s.b.f.support.DisposableBeanAdapter : Invocation of destroy method 'close' failed on bean with name 'eurekaRegistration': org.springframework.beans.factory.BeanCreationNotAllowedException: Error creating bean with name 'org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration': Singleton bean creation not allowed while singletons of this factory are in destruction (Do not request a bean from a BeanFactory in a destroy method implementation!)
2018-04-12 15:59:37.825 INFO 17828 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2018-04-12 15:59:37.828 WARN 17828 --- [ost-startStop-1] o.a.c.loader.WebappClassLoaderBase : The web application [ROOT] appears to have started a thread named [spring.cloud.inetutils] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
java.net.Inet6AddressImpl.getHostByAddr(Native Method)
java.net.InetAddress$2.getHostByAddr(InetAddress.java:932)
java.net.InetAddress.getHostFromNameService(InetAddress.java:617)
java.net.InetAddress.getHostName(InetAddress.java:559)
java.net.InetAddress.getHostName(InetAddress.java:531)
org.springframework.cloud.commons.util.InetUtils$2.call(InetUtils.java:162)
org.springframework.cloud.commons.util.InetUtils$2.call(InetUtils.java:159)
java.util.concurrent.FutureTask.run(FutureTask.java:266)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)
2018-04-12 15:59:37.838 INFO 17828 --- [ main] ConditionEvaluationReportLoggingListener : Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2018-04-12 15:59:37.961 ERROR 17828 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter : ***************************
APPLICATION FAILED TO START
*************************** Description: Field config in com.cloud.web.controller.RibbonConfiguration required a bean of type 'com.netflix.client.config.IClientConfig' that could not be found. Action: Consider defining a bean of type 'com.netflix.client.config.IClientConfig' in your configuration. Process finished with exit code 1
日志关键点在倒数第二行，其实原因很简单ComponentScan不去扫单个Ribbon的配置(RibbonConfigureration)不应用于所有Ribbon客户端，那这个当个客户端去加载的时候就要让Component知道不去管理他，否则就回去扫一遍，看我的Ribbon配置类，55行，被我注释了，没有引用到Exclude注解，所以还是去扫了：
问题很简单，把注解加上就好了。。
贴一下几个类的代码:
1、ExcludeFromComponetScan
public @interface ExcludeFromComponetScan {
}
2、spring cloud启动加载类：
@EnableAutoConfiguration
//excludeFilters这里的意思是，只要标有ExcludeFromComponetScan注解的类都不会去扫描
@ComponentScan(value = "com.cloud", excludeFilters = {@ComponentScan.Filter(type = FilterType.ANNOTATION, value=ExcludeFromComponetScan.class)})
@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
@EnableEurekaClient
@RibbonClient(name = "SPRING-CLOUD-WEB-PROVIDER", configuration = RibbonConfiguration.class)
public class SpringCloudRibbonApplication { public static void main(String[] args) {
SpringApplication.run(SpringCloudRibbonApplication.class, args);
}
}
3、RibbonConfiguration
//这个类不能喝Spring Boot @ConponentScan所在主类放在同一个包或其子包下，否则需要些Exclude类做区分
@ExcludeFromComponetScan
@Configuration
public class RibbonConfiguration {
@Autowired
IClientConfig config; @Bean
public IRule ribbonRule(IClientConfig config) {
//随机算法
return new RandomRule();
}
}