如何使用 webclient 发布正文 x-www-form-urlencoded？答案

【问题标题】：how to post body x-www-form-urlencoded using webclient?如何使用 webclient 发布正文 x-www-form-urlencoded？
【发布时间】：2021-03-14 02:56:30
【问题描述】：

    MultiValueMap<String, String> body_data = new LinkedMultiValueMap();
    body_data.add("param1", {param1});
    ...
    WebClient webClient = WebClient.builder().baseUrl(api_url+request_url)
            .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_FORM_URLENCODED_VALUE)
            .build();

    String result = webClient.post().contentType(MediaType.APPLICATION_FORM_URLENCODED)
                    .bodyValue(BodyInserters.fromFormData(body_data)).retrieve().bodyToMono(String.class).block();

然后它返回

org.springframework.web.reactive.function.client.WebClientRequestException: Content type 'application/x-www-form-urlencoded' not supported for bodyType=org.springframework.web.reactive.function.BodyInserters$DefaultFormInserter; nested exception is org.springframework.web.reactive.function.UnsupportedMediaTypeException: Content type 'application/x-www-form-urlencoded' not supported for bodyType=org.springframework.web.reactive.function.BodyInserters$DefaultFormInserter

对此有什么建议吗？ content-type 应该是 application/x-www-form-urlencoded。

【问题讨论】：

标签： java spring webclient

【解决方案1】：

    We can use BodyInserters.fromFormData for this purpose
    
    webClient client = WebClient.builder()
            .baseUrl("SOME-BASE-URL")
            .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_FORM_URLENCODED_VALUE)
            .build();
    
    return client.post()
            .uri("SOME-URI)
            .body(BodyInserters.fromFormData("username", "SOME-USERNAME")
                    .with("password", "SONE-PASSWORD"))
                    .retrieve()
                    .bodyToFlux(SomeClass.class)
                    .onErrorMap(e -> new MyException("messahe",e))
            .blockLast();


In another form:

MultiValueMap<String, String> formData = new LinkedMultiValueMap<>();
formData.add("username", "XXXX");
formData.add("password", "XXXX");

String response = WebClient.create()
    .post()
    .uri("URL")
    .contentType(MediaType.APPLICATION_FORM_URLENCODED)
    .body(BodyInserters.fromFormData(formData))
    .exchange()
    .block()
    .bodyToMono(String.class)
    .block();

【讨论】：