java - org.springframework.web.client.RestClientException : Could not extract response:

Question

我正在创建一个restful API，它将使用来自服务器的json。但我遇到了以下异常:

org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [[Lexamples.dto.DummyDTO;] and content type [text/json;charset=utf-8] at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:84) at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:454) at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:409) at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:207) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoCachedMethodSite.invoke(PojoMetaMethodSite.java:189) at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:53) at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:120)

代码片段:

List<HttpMessageConverter<?>> msgConverters = restTemplate.getMessageConverters();
msgConverters.add(new MappingJacksonHttpMessageConverter());
restTemplate.setMessageConverters(msgConverters);
DummyDTO[] dummy= restTemplate.getForObject(URI, DummyDTO[].class);

Controller 方法代码:

public UserDTO[] getUserList(){
             List<MediaType> acceptableMediaTypes = new ArrayList<MediaType>();
           acceptableMediaTypes.add(MediaType.APPLICATION_JSON);

        // Set the Accept and Content type header
            HttpHeaders headers = new HttpHeaders();
           headers.setContentType(MediaType.APPLICATION_JSON);
            headers.setAccept(acceptableMediaTypes);
            HttpEntity<?> entity = new HttpEntity<Object>(headers);

            // Add the Jackson message converter
            List<HttpMessageConverter<?>> msgConverters = restTemplate.getMessageConverters();
            msgConverters.add(new MappingJacksonHttpMessageConverter());
            restTemplate.setMessageConverters(msgConverters);

            // Make the HTTP GET request, marshalling the response from JSON to an array of Users
            ResponseEntity<UserDTO[]> responseEntity  =   restTemplate.exchange("http://server.com",HttpMethod.GET, entity, UserDTO[].class);
            return responseEntity.getBody();
        }

请告诉我哪里错了

Answer 1

看起来您更改了请求的内容类型，但“application/json”必须位于响应 header 中，并且您仍然有相同的异常，这一事实表明您在响应 header 中存在错误的媒体类型“text/json”回复，没有这样的media type in HTTP 。只需查看 restTemplate.exchange("http://server.com",HttpMethod.GET,Entity, UserDTO[].class); 的实现，问题就应该出在这里。