Question

我使用spring-webflux WebClient（内部版本20170502.221452-172）来访问生成 Entry 对象（application / stream + json）流的Web应用程序，如下所示：< / p>

final WebClient producerClient = WebClient.create("http://localhost:8080/");

Flux<Entry> entries = producerClient.get().uri("json-stream")
        .accept(MediaType.APPLICATION_STREAM_JSON)
        .exchange()
        .flatMapMany(clientResponse -> clientResponse.bodyToFlux(Entry.class));

虽然 Entry 对象的反序列化适用于使用标准公共类型的POJO，包括Java时间（JSR-310）数据类型，如java.time.Instant，但我想知道我必须做什么为了将任何自定义JSON添加到Java反序列化（例如，自定义Jackson ObjectMapper）。

我无法在WebClient或其构建器和流畅API生成的对象的类中找到任何API来执行此操作。

是否有人使用WebClient进行自定义反序列化？

（也许API还没有，但是？）

Answer 1

以下是为JSON（de）序列化自定义ObjectMapper的示例。请注意，出于流式传输的目的，正在使用不同的编码器/解码器，但其配置原则保持不变。

    ExchangeStrategies strategies = ExchangeStrategies
            .builder()
            .codecs(clientDefaultCodecsConfigurer -> {
                clientDefaultCodecsConfigurer.defaultCodecs().jackson2JsonEncoder(new Jackson2JsonEncoder(new ObjectMapper(), MediaType.APPLICATION_JSON));
                clientDefaultCodecsConfigurer.defaultCodecs().jackson2JsonDecoder(new Jackson2JsonDecoder(new ObjectMapper(), MediaType.APPLICATION_JSON));

            }).build();

    WebClient webClient = WebClient.builder().exchangeStrategies(strategies).build();

Answer 2

基于上述答复，我最终获得了以下代码：

final ObjectMapper mapper = new ObjectMapper()
    .findAndRegisterModules()
    .enable(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT);
final ExchangeStrategies exchangeStrategies = ExchangeStrategies.builder()
    .codecs(configurer -> configurer.defaultCodecs()
    .jackson2JsonDecoder(new Jackson2JsonDecoder(mapper)))
    .build();
final WebClient webClient = WebClient.builder()
    .exchangeStrategies(exchangeStrategies)
    .build();

如果不包括.findAndRegisterModules()，则想反序列化Java 8的时间对象之类的东西时就会遇到问题。

Answer 3

您可以为特定WebClient配置此项：

@Autowired
public ItunesAlbumServiceImpl(ObjectMapper mapper) {
    ExchangeStrategies strategies = ExchangeStrategies.builder().codecs(clientCodecConfigurer ->
        clientCodecConfigurer.customCodecs().decoder(
                new Jackson2JsonDecoder(mapper,
                        new MimeType("text", "javascript", StandardCharsets.UTF_8)))
    ).build();

    webClient = WebClient.builder()
            .exchangeStrategies(strategies)
            .baseUrl("https://itunes.apple.com")
            .build();
}

但也在“应用程序级别”

配置CodecCustomizer：

@Bean
public CodecCustomizer jacksonLegacyJsonCustomizer(ObjectMapper mapper) {
    return (configurer) -> {
        MimeType textJavascript = new MimeType("text", "javascript", StandardCharsets.UTF_8);
        CodecConfigurer.CustomCodecs customCodecs = configurer.customCodecs();
        customCodecs.decoder(
                new Jackson2JsonDecoder(mapper, textJavascript));
        customCodecs.encoder(
                new Jackson2JsonEncoder(mapper, textJavascript));
    };
}

将由WebClientAutoConfiguration作为WebClient.Builder bean生效：

@Autowired
public ItunesAlbumServiceImpl(WebClient.Builder webclientBuilder) {
    webClient = webclientBuilder.baseUrl("https://itunes.apple.com").build();
}

Answer 4

使用webflux 5.0.2，de-registerDefaults ```

val strategies = ExchangeStrategies.builder()
                .codecs { configurer ->
                    configurer.registerDefaults(false)
                    configurer.customCodecs().encoder(Jackson2JsonEncoder(objectMapper, APPLICATION_JSON))
                    configurer.customCodecs().decoder(Jackson2JsonDecoder(objectMapper, APPLICATION_JSON))
                }.build()

```

Answer 5

全局配置：

@Configuration
public class AppConfig {

    private final ObjectMapper objectMapper;

    @Autowired
    public AppConfig(ObjectMapper objectMapper) {
        this.objectMapper = objectMapper;
        this.webClientBuilder = WebClient.builder()
                .exchangeStrategies(exchangeStrategies());
    }

    private ExchangeStrategies exchangeStrategies() {
        Jackson2JsonEncoder encoder = new Jackson2JsonEncoder(objectMapper);
        Jackson2JsonDecoder decoder = new Jackson2JsonDecoder(objectMapper);
        return ExchangeStrategies
                .builder()
                .codecs(configurer -> {
                    configurer.defaultCodecs().jackson2JsonEncoder(encoder);
                    configurer.defaultCodecs().jackson2JsonDecoder(decoder);
                }).build();
    }
}

Answer 6

自春季5.1.13起，您可以使用专用的.codec方法自定义它们：

WebClient.builder()
    .codecs(configurer -> {
        configurer.defaultCodecs().jackson2JsonEncoder(new Jackson2JsonEncoder(new ObjectMapper(), MediaType.APPLICATION_JSON));
        configurer.defaultCodecs().jackson2JsonDecoder(new Jackson2JsonDecoder(new ObjectMapper(), MediaType.APPLICATION_JSON));
     })
    .build();

如何自定义SpringWebFlux WebClient JSON反序列化？

6 个答案: