FeignClients Unsatisfied dependency expressed through field ‘iFeignClientService‘； ...

目录

一，报错信息

二，写法

(一)  service

(二)  控制器调用

三，解决办法

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一，报错信息

2020-10-16 10:58:59.622  WARN 1004 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'TController': Unsatisfied dependency expressed through field 'iFeignClientService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.sgfd.service.IFeignClientService': FactoryBean threw exception on object creation; nested exception is java.lang.NullPointerException
2020-10-16 10:58:59.622  INFO 1004 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]

 

 

二，写法

(一)  service

package com.sgfd.service;

import java.util.Map;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@FeignClient(url="localhost:8088" ,value = "项目名称" )
@RequestMapping("/t")
public interface IFeignClientService {	
	
	/**
     * 物联管理平台下发app镜像仓库地址及相关数据到边设备
     */
    @RequestMapping("/t1")
    @ResponseBody
    public String t1(@RequestBody Map map) ;  	
    
}

(二)  控制器调用

package com.controller;

import com.sgfd.feign.IFeignClientService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import java.util.HashMap;
import java.util.Map;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class TControllerextends {

	@Autowired 
	IFeignClientService  iFeignClientService;
	
	@Override
	public void test(){
		Map operationMap = new HashMap<>();
		operationMap.put("container", "1");//镜像名称
		operationMap.put("version", "2");//镜像版本
		operationMap.put("app", "3");//应用名称
		operationMap.put("control", "4");//  1启动2停止3删除
		iFeignClientService.t1(operationMap)
	}
	
}

三，解决办法

    一开始我以为是大众化的使用问题，注解没写完啊，启动类没加注解啊，包的问题等等。后来都没找对对应的解决办法。于是去看了下官方文档。下面这段话是关键，FeignClient注解失效了。

     在使用FeignClient时，Spring会按name创建不同的ApplicationContext，通过不同的Context来隔离FeignClient的配置信息，在使用配置类时，不能把配置类放到Spring App Component scan的路径下，否则，配置类会对所有FeignClient生效.

 

于是把远程调用的单独分出包，EnableFeignClients注解的路径也变一下

package com.sgfd.feign;

     IFeignClientService 

 

Application

    @SpringBootApplication(scanBasePackages = {"com.sgfd.service","com.sgfd.controller","com.sgfd.mode"})
    @EnableFeignClients(basePackages="com.sgfd.feign")