spring feign client exception handling

Question

I have some fiegn client to send request other micro service.

@FeignClient(name="userservice")
public interface UserClient {

    @RequestMapping(
        method= RequestMethod.GET,
        path = "/userlist"
    )
    String getUserByid(@RequestParam(value ="id") String id);
}

Now I am sending request like this

try {
    String responseData = userClient.getUserByid(id);
    return responseData;
} catch(FeignException e) {
    logger.error("Failed to get user", id);
} catch (Exception e) {
    logger.error("Failed to get user", id);
}

Here the problem is if any FeignException happens I don't get any error code.

I need to send a corresponding error codes in other APIS to send to caller

So how to extract the error code? I want to extract error code and build a responseEntity

I got this code but dont know how exactly I can use in my function.

Answer 1

did you try to implement FallbackFactory on your feign client ?

https://cloud.spring.io/spring-cloud-netflix/multi/multi_spring-cloud-feign.html#spring-cloud-feign-hystrix-fallback

On the create method, before return, you can retrieve the http status code with this snippet :

String httpStatus = cause instanceof FeignException ? Integer.toString(((FeignException) cause).status()) : "";

Exemple :

    @FeignClient(name="userservice", fallbackFactory = UserClientFallbackFactory.class)
    public interface UserClient {
    
        @RequestMapping(
                method= RequestMethod.GET,
                          path = "/userlist")
        String getUserByid(@RequestParam(value ="id") String id);
    
    }
    
    
    @Component
    static class UserClientFallbackFactory implements FallbackFactory<UserClient> {
        @Override
        public UserClient create(Throwable cause) {
    
         String httpStatus = cause instanceof FeignException ? Integer.toString(((FeignException) cause).status()) : "";
    
         return new UserClient() {
            @Override
            public String getUserByid() {
                logger.error(httpStatus);
                // what you want to answer back (logger, exception catch by a ControllerAdvice, etc)
            }
        };
    }
   }