Consider marking one of the beans as @Primary, updating the consumer to accept multiple beans, or us

一、问题

Description:

Field userService in com.yh.controller.UserController required a single bean, but 2 were found:
    - serviceUserServiceImpl: defined in file [C:\Users\wxt\Desktop\dubbo\consumer-service1\target\classes\com\yh\service\ServiceUserServiceImpl.class]
    - userServiceImpl: defined in file [C:\Users\wxt\Desktop\dubbo\provider-service\target\classes\com\yh\service\impl\UserServiceImpl.class]

Action:

Consider marking one of the beans as @Primary, updating the consumer to accept multiple beans, or using @Qualifier to identify the bean that should be consumed

2023-10-02 21:36:32.969  INFO 54384 --- [bboShutdownHook] o.apache.dubbo.config.DubboShutdownHook  :  [DUBBO] Run shutdown hook now., dubbo version: 2.7.3, current host: 192.168.43.212
2023-10-02 21:36:32.970  INFO 54384 --- [bboShutdownHook] o.a.d.r.support.AbstractRegistryFactory  :  [DUBBO] Close all registries [], dubbo version: 2.7.3, current host: 192.168.43.212

Process finished with exit code 1
 

二、分析

因为sringboot通过@Autowired注入接口的实现类时发现有多个，也就是有多个类继承了这个接口，spring容器不知道使用哪一个。

三、解决

1 我自己出现该问题的场景描述：

我在实现dubbo远程调用时出出现的错误；

接口1继承了接口2，然后又在接口1的实现类中使用@Reference将接口2注入。

2 我的解决办法：

接口1不去继承接口2；

在接口1中直接定义方法，在接口1的实现类中使用@Reference将接口2注入。即：

public interface ServiceUserService{
    List findList();
    String msg();
}

@Service
public class ServiceUserServiceImpl implements ServiceUserService {
    @Reference
    private UserService userService;

    public List findList() {
        return userService.findList();
    }

    public String msg() {
        return "消费者1业务层处理业务：consumer-service1"+userService.msg();
    }
}

另外，我还看到了其他博主的解决方法

第一种、加@Primary表示某个实现类首选注入

@Configuration（""）

public class ActivitiConfig {

   @Autowired

   ProcessEngineConfiguration processEngineConfiguration;

   //流程配置，与spring整合采用SpringProcessEngineConfiguration这个实现

   @Bean

   @Primary

   public ProcessEngineConfiguration processEngineConfiguration(DataSource dataSource,

                                                                PlatformTransactionManager transactionManager){

       return processEngineConfiguration;

   }

}

第二种、@Autowired和@Qualifier(value = "beanName")结合使用

@Configuration

public class ActivitiConfig {

   @Autowired

   @Qualifier(value = "processEngineConfigurationImpl")

   ProcessEngineConfiguration processEngineConfiguration；

}

@Service("processEngineConfigurationImpl")

public class ProcessEngineConfigurationImpl extends  ProcessEngineConfiguration{

}