Finchley.SR1版本的openfeign@Autowired注解的一个坑

我是跟着尚硅谷的SpringCloud教程学的，然后在写代码的时候用了比较新的版本去替代视频里的教学版本。

这个问题出现在引入feign组件的时候。

使用SpringCloud的Finchley.SR1版本

引用openfeign替代了 feign，原因如下

链接地址https://stackoverflow.com/questions/49823158/differences-between-netflix-feign-openfeign

大意是说feign是旧版本，16年就不再更新了，现在SpringCloud使用openfein去替代feign

1，在公用service接口层实现@FeignClient注解

@FeignClient(value = "MICROSERVICECLOUD-DEPT")
public interface DeptClientService
{
	@RequestMapping(value = "/dept/get/{id}", method = RequestMethod.GET)
	public Dept get(@PathVariable("id") long id);

	@RequestMapping(value = "/dept/list", method = RequestMethod.GET)
	public List<Dept> list();

	@RequestMapping(value = "/dept/add", method = RequestMethod.POST)
	public boolean add(Dept dept);
}

然后执行maven 的 clean 和 install，供其他模块调用

2，在feign模块的controller层调用 

@RestController
public class DeptController_Consumer
{
	@Autowired
	private DeptClientService service;

	@RequestMapping(value = "/consumer/dept/get/{id}")
	public Dept get(@PathVariable("id") Long id)
	{
		return this.service.get(id);
	}

	@RequestMapping(value = "/consumer/dept/list")
	public List<Dept> list()
	{
		return this.service.list();
	}

	@RequestMapping(value = "/consumer/dept/add")
	public Object add(Dept dept)
	{
		return this.service.add(dept);
	}
}

此时IDEA针对service报错：Could not autowire. No beans of 'DeptClientService' type found. less... (⌘F1) 
Inspection info:Checks autowiring problems in a bean class.

这里报错不影响代码执行，但是我没理解深层原因。按说正常调用@Autowired

不会报错。

feign主启动类类如下

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients(basePackages= {"com.atguigu.spring.microservicecloudconsumerdeptfeign"})
@ComponentScan("com.atguigu.spring.microservicecloudconsumerdeptfeign")
public class MicroservicecloudConsumerDeptFeignApplication {

    public static void main(String[] args) {
        SpringApplication.run(MicroservicecloudConsumerDeptFeignApplication.class, args);
    }
}

注解@ComponentScan报红，提示@SpringBootApplication注解已经扫描过该包，但不影响程序运行

启动之后直接挂掉，报错提示如下

Description:

Field service in com.atguigu.spring.microservicecloudconsumerdeptfeign.controller.DeptController_Consumer required a bean of type 'com.atguigu.spring.microservicecloudapi.service.DeptClientService' that could not be found.


Action:

Consider defining a bean of type 'com.atguigu.spring.microservicecloudapi.service.DeptClientService' in your configuration.

应该是service没有注入进去，找不到。

这个阶段我还分析不了原因，所以搜了一下，找到一个可能的解决方式

链接https://stackoverflow.com/questions/30241198/error-injecting-feignclient-from-another-project

于是把主启动类注解改成

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients(basePackages= {"com.atguigu.spring.microservicecloudapi.service","com.atguigu.spring.microservicecloudconsumerdeptfeign"})
public class MicroservicecloudConsumerDeptFeignApplication {

    public static void main(String[] args) {
        SpringApplication.run(MicroservicecloudConsumerDeptFeignApplication.class, args);
    }
}

项目正常启动，访问正常