Question

我创建了一个带有Map 参数

的API

@RequestMapping(value = "upload", method = RequestMethod.POST)
public ResponseEntity<String> handleContactsFileUpload(@RequestParam("file") MultipartFile file,
                                                       @RequestParam("name") String name,
                                                       @RequestParam("campaignAppItemId") Long campaignAppItemId,
                                                       @RequestParam("fileColumnHeaders") Map<String,Integer> fileColumnHeaders) throws Exception {
    if (file == null)
        return new ResponseEntity<>("No file uploaded", HttpStatus.BAD_REQUEST);
    contactService.handleContactsFile(file, name, campaignAppItemId,fileColumnHeaders);
    return new ResponseEntity<>("File uploaded successfully", HttpStatus.OK);
}

我正试图通过邮递员打电话给这个

Postman Screenshot

我像在SS中那样在Body-> Form Data中传递了fileColumnHeaders

然后我在邮递员那里收到了这样的消息

无法将类型“ java.lang.String”的值转换为所需的类型“ java.util.Map”；嵌套的异常是java.lang.IllegalStateException：无法将“ java.lang.String”类型的值转换为所需的“ java.util.Map”类型：找不到匹配的编辑器或转换策略。

有人知道为什么会收到此消息吗？如何在Rest API请求中将地图作为参数传递？我们如何通过邮递员传递地图？

任何帮助都会帮助

Answer 1

对于Maps和其他非平凡的数据类型和对象，您可以使用@RequestBody而不是@RequestParam-这样，spring会将代表您的map参数的JSON映射到域对象，该对象随后可以序列化并可以转换为java对象。

Answer 2

首先，创建DTO对象以从请求中获取所有数据。

public class FormDataDTO {

    private MultipartFile file;

    private String name;

    private Long campaignAppItemId;

    private Map<String,Integer> fileColumnHeaders;

    // getters, setters
}

第二，您可以从请求中映射FormDataDTO，而无需任何注释：

@RequestMapping(value = "upload", method = RequestMethod.POST)
public ResponseEntity<String> handleContactsFileUpload(FormDataDTO formDataDTO){
    // your logic code here
}

最后，您请求中的表单数据将为：

Answer 3

我认为这可行：

@RequestMapping(value = "upload/{fileColumnHeaders}", method = RequestMethod.POST)
public ResponseEntity<String> handleContactsFileUpload(@RequestParam("file") MultipartFile file,
                                                       @RequestParam("name") String name,
                                                       @RequestParam("campaignAppItemId") Long campaignAppItemId,
                                                       @MatrixVariable Map<String,Integer> fileColumnHeaders) throws Exception {
    if (file == null)
        return new ResponseEntity<>("No file uploaded", HttpStatus.BAD_REQUEST);
    contactService.handleContactsFile(file, name, campaignAppItemId,fileColumnHeaders);
    return new ResponseEntity<>("File uploaded successfully", HttpStatus.OK);
}

将所有其他参数放入正文中，但是将fileColumnHeaders添加到网址中，如下所示：

/upload/firstName=1;lastName=2;address=3;phone=4

您还需要以下额外配置：

@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void configurePathMatch(PathMatchConfigurer configurer) {
        UrlPathHelper urlPathHelper = new UrlPathHelper();
        urlPathHelper.setRemoveSemicolonContent(false);
        configurer.setUrlPathHelper(urlPathHelper);
    }
}

Answer 4

...或者只是创建一个转换器：

@Component
@RequiredArgsConstructor
public class StringToMapConverter implements Converter<String, Map<String, Object>> {

  private final ObjectMapper objectMapper;

  @Override
  public Map<String, Object> convert(String source) {
    try {
      return objectMapper.readValue(source, new TypeReference<Map<String, String>>() {
      });
    } catch (final IOException e) {
      return null;
    }
  }

}

在RestAPI发布请求中作为参数映射

4 个答案: