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 dont 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

I'm late to party but here are my 2 cents. We had same use case to handle exceptions based on error code and we used custom ErrorDecoder.

public class CustomErrorDecoder implements ErrorDecoder {

    @Override
    public Exception decode(String methodKey, Response response) {
        String requestUrl = response.request().url();
        Response.Body responseBody = response.body();
        HttpStatus responseStatus = HttpStatus.valueOf(response.status());

        if (responseStatus.is5xxServerError()) {
            return new RestApiServerException(requestUrl, responseBody);
        } else if (responseStatus.is4xxClientError()) {
            return new RestApiClientException(requestUrl, responseBody);
        } else {
            return new Exception("Generic exception");
        }
    }
}

Return @Bean of above class in FeignClientConfiguration class.

public class MyFeignClientConfiguration {

    @Bean
    public ErrorDecoder errorDecoder() {
        return new CustomErrorDecoder();
    }
}

Use this as your config class for FeignClient.

@FeignClient(value = "myFeignClient", configuration = MyFeignClientConfiguration.class)

Then you can handle these exceptions using GlobalExceptionHandler.