Webclient Error Handling - Spring Webflux

Question

I want to throw my custom exceptions with the following conditions:

If I am getting proper error response in json format, I want to deserialize it and throw my exception named CommonException inside onStatus()
If I am receiving an HTML content as part of response or deserialization didnt happen successfully then I want to throw GenericException which I am creating inside onErrorMap()

While throwing a GenericException, I want to pass the same HttpStatus code to upstream which I am getting from downstream response.

 IdVerificationResponse idVerificationResponse = client.get()
 .uri(idVerificationUrl)
 .headers(headers -> headers.addAll(httpEntity.getHeaders()))
 .retrieve()
 .onStatus(HttpStatus::isError, response ->
     //Throw this one only if deserialization of error response to IdVerificationErrorResponse class happens successfully

     response.bodyToMono(IdVerificationErrorResponse.class)
         .flatMap(error -> Mono.error(CommonException.builder().message(error.getCustomMessage()).build()))
 )
 .bodyToMono(IdVerificationResponse.class)
 .onErrorMap(error -> {
     //Come over here only if there is an error in deserialization in onStatus()

     //How to get the HttpStatus we are getting as part of error response from the downstream
     HttpStatus httpStatus = HttpStatus.BAD_REQUEST;
     ApiErrorDetails errorDetailsObj = ApiErrorDetails.builder().errorCode(httpStatus.name()).errorDescription("Error related to HTML")
           .errorDetails("Error related to HTML").build();
     ErrorDetails errorDetails = ErrorDetails.builder().errors(errorDetailsObj).build();
     return GenericException.builder().errorDetails(errorDetails).httpStatus(httpStatus).build();
 }).block();

Currently onErrorMap() is getting called everytime and overriding the exception I am throwing inside onStatus()

Harsh Kanakhara Harsh Kanakhara · Accepted Answer · 2021-05-17T16:47:06

Found the solution

IdVerificationResponse idVerificationResponse = client.get()
    .uri(processCheckUrl)
    .headers(headers -> headers.addAll(httpEntity.getHeaders()))
    .retrieve()
    .onStatus(HttpStatus::isError, response -> {
            HttpStatus errorCode = response.statusCode();
            return response.bodyToMono(IdVerificationErrorResponse.class)
                .onErrorMap(error -> new Exception("Throw your generic exception over here if there is any error in deserialization"))
                .flatMap(error -> Mono.error(new Exception("Throw your custom exception over here after successful deserialization")));
        })
    .bodyToMono(IdVerificationResponse.class).block();

Webclient Error Handling - Spring Webflux

1 Answers