Rest API 以纯字符串形式发送响应，但内容类型为“application/json;charset=UTF-8”。 我如何阅读回复

Question

We are consuming a third party rest API that returns a UUID as a response to a POST request. The MediaType of the response is application/json , however the returned uuid is returned as plain text and not as a JSON like "7c49cec7-8ae8-44c8-bc27-866b6efcfe59" (with quotes). I have attached MappingJackson2HttpMessageConverter to the Spring RestTemplate. It appears(I'm not sure) that since content type is application/json it tries to parse it as JSON and fails to parse it because it doesn't contain double quotes. Following is the exception

org.springframework.web.client.RestClientException: Error while extracting response for type [class java.lang.Object] and content type [application/json;charset=UTF-8]; nested exception is org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Unexpected character ('d' (code 100)): Expected space separating root-level values; nested exception is com.fasterxml.jackson.core.JsonParseException: Unexpected character ('d' (code 100)): Expected space separating root-level values
 at [Source: (PushbackInputStream); line: 1, column: 3]

Code:

@Test
public void test1() {
  String uuid = restTemplate.postForObject("/order", orderDTO, String.class);
    assertThat(uuid).isNotNull();
}

How can I deal with this situation?

Answer 1

I tried the following solution. It works, but it also forces the conversion of all other media type application/json responses to be handled by StringHttpMessageConverter instead of MappingJackson2HttpMessageConverter . I added an interceptor which intercepts the reponse before converting it and then modifies the content type.

List<HttpMessageConverter<?>> messageConverters = new ArrayList<>();

MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
converter.setSupportedMediaTypes(List.of(MediaType.APPLICATION_JSON));
messageConverters.add(converter);

StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter();
stringHttpMessageConverter.setSupportedMediaTypes(List.of(MediaType.TEXT_PLAIN));
messageConverters.add(stringHttpMessageConverter);

restTemplate
        .getInterceptors()
        .add(
                (request, body, execution) -> {
                    ClientHttpResponse response = execution.execute(request, body);
                    response.getHeaders().setContentType(MediaType.TEXT_PLAIN);
                    return response;
                });