WebClientConfigurer overrides exchange strategies

[marcingrzejszczak]

Not sure if feature or bug ;) (Hateoas version 1.0.0.M1)

public class WebClientConfigurer {

    private final ObjectMapper mapper;
    private final Collection<HypermediaMappingInformation> hypermediaTypes;

    /**
     * Return a set of {@link ExchangeStrategies} driven by registered {@link HypermediaType}s.
     *
     * @return a collection of {@link Encoder}s and {@link Decoder} assembled into a {@link ExchangeStrategies}.
     */
    public ExchangeStrategies hypermediaExchangeStrategies() {

        List<Encoder<?>> encoders = new ArrayList<>();
        List<Decoder<?>> decoders = new ArrayList<>();

        this.hypermediaTypes.forEach(hypermedia -> {

            ObjectMapper objectMapper = hypermedia.configureObjectMapper(this.mapper.copy());
            MimeType[] mimeTypes = hypermedia.getMediaTypes().toArray(new MimeType[0]);

            encoders.add(new Jackson2JsonEncoder(objectMapper, mimeTypes));
            decoders.add(new Jackson2JsonDecoder(objectMapper, mimeTypes));
        });

        encoders.add(CharSequenceEncoder.allMimeTypes());
        decoders.add(StringDecoder.allMimeTypes());

        return ExchangeStrategies.builder().codecs(clientCodecConfigurer -> {

            encoders.forEach(encoder -> clientCodecConfigurer.customCodecs().encoder(encoder));
            decoders.forEach(decoder -> clientCodecConfigurer.customCodecs().decoder(decoder));

            clientCodecConfigurer.registerDefaults(false);
        }).build();
    }

    /**
     * Register the proper {@link ExchangeStrategies} for a given {@link WebClient}.
     *
     * @param webClient
     * @return mutated webClient with hypermedia support.
     */
    public WebClient registerHypermediaTypes(WebClient webClient) {
        return webClient.mutate().exchangeStrategies(hypermediaExchangeStrategies()).build();
    }
}

this

  public WebClient registerHypermediaTypes(WebClient webClient) {
        return webClient.mutate().exchangeStrategies(hypermediaExchangeStrategies()).build();
    }

overrides the existing exchangeStrategies, which results in

org.springframework.web.reactive.function.UnsupportedMediaTypeException: Content type 'text/plain;charset=UTF-8' not supported for bodyType=org.springframework.core.io.buffer.DataBuffer

when working with Sleuth.

[odrotbohm]

@gregturn – Is this related to #885?

[gregturn]

Apply spring-projects/spring-framework#22612 when Spring HATEOAS is used with Spring Framwork 5.2.

Retain existing solution when using Spring Framework 5.1.

[gregturn]

Indeed, #885 duplicates this issue, so I dispositioned it and closed it. I also linked the original Spring Framework issue in here, so we could track everything from here.

[odrotbohm]

I've upgraded to Spring Framework 5.2 snapshots for #919, feel free to prepare the necessary changes.

[gregturn]

Resolved via fc3767b.