java - OAuth2RestTemplate.postForEntity RestClientException：[org.x.xx] 和内容类型 [application/json] 没有 HttpMessageConverter

Question

我OAuth2RestTemplate用来查询接受 JSON 对象的外部 api。

HttpHeaders headers = new HttpHeaders();
headers.add(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE);
HttpEntity<XX> request = new HttpEntity<>(xX, headers);
ResponseEntity<String> response = oAuth2RestTemplate.postForEntity(url , request, String.class);

我得到了这个错误：

org.springframework.web.client.RestClientException: No HttpMessageConverter for [com.yy.XX] and content type [application/json]
    at org.springframework.web.client.RestTemplate$HttpEntityRequestCallback.doWithRequest(RestTemplate.java:956) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:732) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]

我试图添加MappingJackson2HttpMessageConverter到我的 oAuth2RestTemplate 但我得到了同样的错误。