Correct way of handling errors with Spring WebClient (Reactor HTTPClient)

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I have a basic application that downloads data from a website, but the request often returns 404 not found errors or a PrematureCloseException. My question is how can I implement my client in a way that it automatically retries if it encounters a PrematureCloseException, but allows to handle 404 later in the stream while also setting a cache when the request is successful.

Current code:

 httpClient.get()
            .uri(URL)
            .retrieve()
            .bodyToMono(ByteArrayResource.class)
//Retry until the server responds "correctly"
            .retryWhen(Retry.indefinitely().filter(t -> t instanceof PrematureCloseException))
            .map(ByteArrayResource::getByteArray)
            .doOnNext(next -> cache.set(next)) //Set the cache only if the request is successful

//Passed to another method
            .ifError(error -> logger.error("Error encountered {}", error)) //Somehow handle all exceptions (not the PrematureCloseExceptions)
            .subscribe(data -> {
               //Successful request
            })
reactor-netty project-reactor spring-webflux java
1 Answers

You are almost there. Your retryWhen is configured correctly, and your doOnNext handles the cache correctly.

To handle errors, you can use Flux.doOnError, which works similar as doOnNext.

Patrick Hooijer0
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