java - Spring RestTemplate 无法解析 json 响应

Question

如果我将 POST 的响应解析为字符串，它会完美地工作:

ResponseEntity<String> stringResponse = restTemplate.postForEntity(DruidClient.QUERY_HOST + "/druid/v2", query, String.class);
String valueResults = stringResponse.getBody();
DruidValueResult[] results = new ObjectMapper().readValue(valueResults, DruidValueResult[].class);

但是，如果我告诉 spring 直接解析响应:

ResponseEntity<DruidValueResult[]> results = restTemplate.postForEntity(DruidClient.QUERY_HOST + "/druid/v2", query, DruidValueResult[].class);

我收到以下错误:

org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class [Lcom.dripstat.metricprocessor.druid.DruidValueResult;] and content type [application/smile]
at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:108)
at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:788)
at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:773)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:553)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:506)
at org.springframework.web.client.RestTemplate.postForEntity(RestTemplate.java:361)

为什么spring不能直接解析生成的json？

Answer 1

来自SpringSource Blog :

Objects passed to and returned from the methods getForObject(), postForLocation(), and put() and are converted to HTTP requests and from HTTP responses by HttpMessageConverters. Converters for the main mime types and Java types are registered by default, but you can also write your own converter and plug it in the RestTemplate. In the example below, I will show you how that's done.

我认为 postForEntity() 也是如此，因此您可能需要为您的特定 mime 类型添加消息转换器，因为默认情况下它不会被编码:

<bean id="restTemplate" class="org.springframework.web.client.RestTemplate">
  <property name="messageConverters">
    <list>
      <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
        <property name="supportedMediaTypes" value="application/smile" />
        <property name="supportedMediaTypes" value="text/javascript" />
      </bean>
    </list>
  </property>
</bean>