如何将 RestTemplate 与 application/octet-stream 响应类型一起使用

Posted 2023-02-26

【中文标题】如何将 RestTemplate 与 application/octet-stream 响应类型一起使用

【英文标题】：How to use RestTemplate with application/octet-stream response type

【发布时间】：2016-12-21 15:56:00

【问题描述】：

我正在使用ISBNdB 来获取有关书籍的信息。响应类型是应用程序/八位字节流。我得到的示例 json 响应如下所示

"index_searched" : "isbn",
"data" : [
  
     "publisher_id" : "john_wiley_sons_inc",
     "publisher_name" : "John Wiley & Sons, Inc",
     "title_latin" : "Java programming interviews exposed",
     "language" : "eng",
     "summary" : "",
     "physical_description_text" : "1 online resource (xvi, 368 pages) :",
     "author_data" : [
        
           "name" : "Markham, Noel",
           "id" : "markham_noel"
        ,
        
           "id" : "greg_milette",
           "name" : "Greg Milette"
        
     ],
     "title_long" : "Java programming interviews exposed",
     "urls_text" : "",
     "publisher_text" : "New York; John Wiley & Sons, Inc",
     "book_id" : "java_programming_interviews_exposed",
     "awards_text" : "; ",
     "subject_ids" : [],
     "isbn13" : "9781118722862",
     "lcc_number" : "",
     "title" : "Java programming interviews exposed",
     "isbn10" : "1118722868",
     "dewey_decimal" : "005.13/3",
     "edition_info" : "; ",
     "notes" : "\"Wrox programmer to programmer\"--Cover.; Acceso restringido a usuarios UCM = For UCM patrons only.",
     "marc_enc_level" : "",
     "dewey_normal" : "5.133"
  
  ]
  

我正在使用 Jackson 来转换此响应。我的 Pojo 如下所示

@JsonIgnoreProperties(ignoreUnknown = true)

public class value 
    private  String index_searched;
    // Another pojo in different file with ignore properties
    private data[] dat;

    public value()

    
    public data[] getDat() 
        return dat;
    

    public void setDat(data[] dat) 
        this.dat = dat;
    
    public String getIndex_searched() 
        return index_searched;
    
    public void setIndex_searched(String index_searched) 
        this.index_searched = index_searched;
     
   

当我尝试关注时

  value book = restTemplate.getForObject(FINAL_URL, value.class);

我得到了这个异常

org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class com.rocketrenga.mylibrary.domain.value] and content type [application/octet-stream]

但我可以将响应映射到字符串

String book = restTemplate.getForObject(FINAL_URL, String.class);
ObjectMapper mapper = new ObjectMapper();
value val = mapper.readValue(book, value.class);
System.out.println(val.getIndex_searched());

如何直接映射响应 POJO 而不是 String 并转换回 POJO

【问题讨论】：

到目前为止，您尝试将响应直接转换为 pojo 的方法是什么？

我已经说明了我在我的问题中尝试过的内容。我尝试的部分......

问题出在服务器端。为什么要发送内容类型为 application/octet-stream 的 JSON？

@AndyWilkinson。这就是我从 ISBNdb 收到的。我无法控制它。

呃。然后，您应该按照@jny 下面的建议进行操作，并使用基于 Jackson 的转换器配置您的 RestTemplate，该转换器将 application/octet-stream 响应视为 JSON。

【参考方案1】：

您需要使用消息转换器配置 restTemplate。在您的配置中执行以下操作：

   @Bean
    public RestOperations restTemplate() 
        RestTemplate restTemplate = new RestTemplate();
        
        MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();

        
        converter.setSupportedMediaTypes(
                Arrays.asList(new MediaType[]MediaType.APPLICATION_JSON, MediaType.APPLICATION_OCTET_STREAM));

        restTemplate.setMessageConverters(Arrays.asList(converter, new FormHttpMessageConverter()));
        return restTemplate;
    

【参考方案2】：

我想更好的解决方案是添加另一个转换器，而不是修改当前的：

@Bean
public RestTemplate restTemplate() 
    final RestTemplate restTemplate = new RestTemplate();
    restTemplate.getMessageConverters().add(jacksonSupportsMoreTypes());
    return restTemplate;



private HttpMessageConverter jacksonSupportsMoreTypes() //eg. Gitlab returns JSON as plain text 
    MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
    converter.setSupportedMediaTypes(Arrays.asList(MediaType.parseMediaType("text/plain;charset=utf-8"), MediaType.APPLICATION_OCTET_STREAM));
    return converter;