SpringCloud使用feign远程调用服务注入映射接口失败问题

springCloud使用feign远程调用服务注入映射接口失败

在一次项目中，使用feign远程调用服务时，发现feign的映射接口一直注入容器失败

映射接口

package com.jn.feign.api;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
@FeignClient("RIBBON-PROVIDER")
@RequestMapping(value = "/provider")
public interface IProviderClient {
    @RequestMapping("/test1")
    String test1();
//
//    //方法接收多个参数
    @RequestMapping("/login")
    String login(@RequestParam("username") String username, @RequestParam("password") String password);
//
//    //方法接收对象
    @RequestMapping("/addUserFrom")
    String addUserFrom(User user);

//    //方法接收JSON数据
    @RequestMapping("/addUserJson")
    String addUserJson(@RequestBody User user);
//
//    //restful风格
    @RequestMapping("/getUserById/{id}")
    String getUserByID(@PathVariable Integer id);

}

主启动类

@SpringBootApplication
@ComponentScan("com.jn")
@EnableEurekaClient
@EnableFeignClients("com.jn.feign.api")//开启feign机制，并指定映射接口路径
public class Day0111SpringcloudFeignConsumerApplication {

    public static void main(String[] args) {
        SpringApplication.run(Day0111SpringcloudFeignConsumerApplication.class, args);
    }
}

调用的controller

@RestController
@RequestMapping("/feign")
public class FeignController {
    @Autowired
    IProviderClient client;
    @GetMapping("/test")
    public String test(){
        String s = client.test1();
        return s;
    }
}

启动后报错信息

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘feignController‘: Unsatisfied dependency expressed through field ‘client‘; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘com.qf.feign.api.IProviderClient‘: FactoryBean threw exception on object creation; nested exception is java.lang.IllegalStateException: PathVariable annotation was empty on param 0.

eureka服务器也确定RIBBON-PROVIDER已经注册上去了，最终在检查下发现了映射接口使用restful风格调用的时候@PathVariable没有指定参数的id

修改后

在使用feign携带参数远程调用服务的时候，一定要指定参数名，它不能像springMVC一样将形参自动的作为参数值，需要自己手动指定

SpringCloud使用feign远程调用服务注入映射接口失败问题

原文：https://www.cnblogs.com/codeli/p/13579764.html