1）引入依赖

<!‐‐ openfeign 远程调用 ‐‐>
<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring‐cloud‐starter‐openfeign</artifactId>
</dependency>

2）编写调用接口+@FeignClient注解

@FeignClient(value = "mall‐order",path = "/order")
public interface OrderFeignService {

  @RequestMapping("/findOrderByUserId/{userId}")
  public R findOrderByUserId(@PathVariable("userId") Integer userId);
}

3）调用端在启动类上添加@EnableFeignClients注解

@SpringBootApplication
@EnableFeignClients
public class MallUserFeignDemoApplication {
  public static void main(String[] args) {
  	SpringApplication.run(MallUserFeignDemoApplication.class, args);
  }
}

4）发起调用，像调用本地方式一样调用远程服务

@RestController
@RequestMapping("/user")
public class UserController {

  @Autowired
  OrderFeignService orderFeignService;

  @RequestMapping(value = "/findOrderByUserId/{id}")
  public R findOrderByUserId(@PathVariable("id") Integer id) {
  	//feign调用
  	R result = orderFeignService.findOrderByUserId(id);
  	return result;
  }
}