spring cloud feign在2.x版本中feign client名称重复无法启动的解决方案

解决spring cloud feign在2.x版本中feign client名称重复的问题

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APPLICATION FAILED TO START

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Description:

The bean 'trip-operation-core.FeignClientSpecification', defined in null, could not be registered. A bean with that name has already been defined in null and overriding is disabled.

Action:

Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true

Disconnected from the target VM, address: '127.0.0.1:56071', transport: 'socket'

Process finished with exit code 1

解决办法：

1.设置beanName可以重复。不推荐，springboot2.x也不推荐这种做法，会覆盖已存在的bean

spring.main.allow-bean-definition-overriding=true

2.设置@FeignClient的contextId属性，推荐使用。

示例：

@FeignClient(value = "trip-operation-core", contextId = "trip-operation-core-TenantClient")

@FeignClient(value = "trip-operation-core", contextId = "trip-operation-core-tenant-temp-client")

注意contextId要尽量独一无二，不要和其他服务的client的contextId重复，推荐服务名加类名，例如：服务是trip-operation-core, 接口类名是TenantClient，则全名取

trip-operation-core-tenant-client或者trip-operation-core-TenantClient

feign源码：

org.springframework.cloud.openfeign.FeignClientsRegistrar#getClientName

private String getClientName(Map client) {

   if (client == null) {

      return null;

   }

   String value = (String) client.get("contextId");

   if (!StringUtils.hasText(value)) {

      value = (String) client.get("value");

   }

   if (!StringUtils.hasText(value)) {

      value = (String) client.get("name");

   }

   if (!StringUtils.hasText(value)) {

      value = (String) client.get("serviceId");

   }

   if (StringUtils.hasText(value)) {

      return value;

   }

   throw new IllegalStateException("Either 'name' or 'value' must be provided in @"

         + FeignClient.class.getSimpleName());

}

参考教程： https://juejin.im/post/5e13e8116fb9a0481e2796a3

官方教程：

https://cloud.spring.io/spring-cloud-openfeign/2.1.x/single/spring-cloud-openfeign.html#spring-cloud-feign-overriding-defaults

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