将HTTP响应作为java对象获取

Question

我正在使用Spring Web创建休息资源。我用Java创建了类似于Json响应的Document对象。当我使用String.class作为响应类型时，我从请求中获得响应。当我将响应更改为我创建的类时，该男孩为空。

这是我的HttpGettter

   private <T> T perform(String token, String resourcePath, Class<T> responseType, HttpMethod method, MultiValueMap<String, String> queryParams) {
     UriComponentsBuilder uriComponentsBuilder = UriComponentsBuilder.newInstance()
          .scheme(protocol)
          .host(host);

    UriComponents uriComponents = uriComponentsBuilder.build();
    String url = uriComponents.toString();

    HttpHeaders headers = new HttpHeaders();
    headers.add("contentType","application/json");

    HttpEntity<String> requestEntity = new HttpEntity<>(headers);
    ResponseEntity<T> responseEntity = restTemplate.exchange(url, method, requestEntity, responseType);
    return responseEntity.getBody();
   }
     return null;
 }

Json文件

@JsonIgnoreProperties(ignoreUnknown = false)
public class SiteDocument {

  @JsonProperty("id")
  private int siteID;
  @JsonProperty("site_name")
  private String siteName;
  @JsonProperty("url")
  private String url;
}

函数调用

 perform(null, "/sites", SiteDocument[].class, HTTP.get,null)

JSON响应

{  
 "items":[  
  {  
     "id":5841970702,
     "site_name":"test",
     "url":"http://sample/again/",
     "pages":2,
     "policies":0,
     "product":[  
        "quality_assurance",
        "accessibility",
        "seo",
        "policy"
     ],
     "_links":{  
        "site":{  
           "href":"https://api.siteimprove.com/v2/sites/5841970702"
        }
     }
  },

  {  
     "id":5881398958,
     "site_name":"preview.site",
     "url":"http://sample.site",
     "pages":0,
     "policies":0,
     "product":[  
        "quality_assurance",
        "policy"
     ],
     "_links":{  
        "site":{  
           "href":"https://api.siteimprove.com/v2/sites/5881398958"
        }
     }
  }
 ],
 "total_items":5,
 "total_pages":1,
  "links":{  
  "self":{  
     "href":"https://api.siteimprove.com/v2/sites"
  }
  }
  }

忽略JSON响应的不正确格式。编辑简短。

例外

线程“main”org.springframework.web.client.RestClientException中的异常：无法提取响应：没有为响应类型找到合适的HttpMessageConverter [类[Lcom.blueprint.siteimprove.webresources.documents.SiteDocument;]和内容类型[text / HTML]

更新的例外

无法提取响应：没有为响应类型找到合适的HttpMessageConverter [类[Lcom.coremedia.blueprint.siteimprove.webresources.documents.SiteDocument;]和内容类型[application / json; charset = utf-8]

在标题上添加以下内容

  headers.add("Accept","application/json");
  headers.add("Content-Type","application/json");

Answer 1

问题出在POM文件中。 POM文件中未添加运行时依赖项。将在POM文件中添加以下依赖项。

  <dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
  </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <scope>runtime</scope>
    </dependency>