Spring Webflux : Webclient : Get body on error

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Spring Webflux : Webclient : Get body on error

Solution 1

I prefer to use the methods provided by the ClientResponse to handle http errors and throw exceptions:

         .uri( url )
         .body( bodyObject == null ? null : BodyInserters.fromValue( bodyObject ) )
         .accept( MediaType.APPLICATION_JSON )
         .headers( headers )
         .flatMap( clientResponse -> {
             //Error handling
             if ( clientResponse.statusCode().isError() ) { // or clientResponse.statusCode().value() >= 400
                 return clientResponse.createException().flatMap( Mono::error );
             return clientResponse.bodyToMono( clazz )
         } )
         //You can do your checks: doOnError (..), onErrorReturn (..) ...

In fact, it’s the same logic used in the DefaultResponseSpec of DefaultWebClient to handle errors. The DefaultResponseSpec is an implementation of ResponseSpec that we would have if we made a retrieve() instead of exchange().

Original Author Omar ZRIDI Of This Content

Solution 2

Don’t we have onStatus()?

    public Mono<Void> cancel(SomeDTO requestDto) {
        return webClient.post().uri(SOME_URL)
                .header("API_KEY", properties.getApiKey())
                .onStatus(HttpStatus::isError, response -> {
                    logTraceResponse(log, response);
                    return Mono.error(new IllegalStateException(
                            String.format("Failed! %s", requestDto.getCartId())


    public static void logTraceResponse(Logger log, ClientResponse response) {
        if (log.isTraceEnabled()) {
            log.trace("Response status: {}", response.statusCode());
            log.trace("Response headers: {}", response.headers().asHttpHeaders());
                    .subscribe(body -> log.trace("Response body: {}", body));

Original Author WesternGun Of This Content

Solution 3

You could also do this

return webClient.getWebClient()
 .flatMap(clientResponse -> {
     if (clientResponse.statusCode().is5xxServerError()) {
        clientResponse.body((clientHttpResponse, context) -> {
           return clientHttpResponse.getBody();
     return clientResponse.bodyToMono(String.class);
     return clientResponse.bodyToMono(String.class);

Read this article for more examples link, I found it to be helpful when I experienced a similar problem with error handling

Original Author Mohale Of This Content

Solution 4

I got the error body by doing like this:

.onStatus(HttpStatus::isError, response -> response.bodyToMono(String.class) // error body as String or other class
                                                   .flatMap(error -> Mono.error(new RuntimeException(error)))) // throw a functional exception

Original Author Karim G Of This Content


So This is all About This Tutorial. Hope This Tutorial Helped You. Thank You.

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I am an Information Technology Engineer. I have Completed my MCA And I have 4 Year Plus Experience, I am a web developer with knowledge of multiple back-end platforms Like PHP, Node.js, Python and frontend JavaScript frameworks Like Angular, React, and Vue.

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