带有混合多部分请求的@RequestPart,Spring MVC 3.2

Question

我正在开发基于Spring 3.2的RESTful服务.我正面临一个控制器处理混合多部分HTTP请求的问题,第二部分使用XML或JSON格式化数据,第二部分使用图像文件.

我正在使用@RequestPart注释来接收请求

@RequestMapping(value = "/User/Image", method = RequestMethod.POST,  consumes = {"multipart/mixed"},produces="applcation/json")

public
ResponseEntity<List<Map<String, String>>> createUser(
        @RequestPart("file") MultipartFile file, @RequestPart(required=false) User user) {

    System.out.println("file" + file);

    System.out.println("user " + user);

    System.out.println("received file with original filename: "
            + file.getOriginalFilename());

    // List<MultipartFile> files = uploadForm.getFiles();
    List<Map<String, String>> response = new ArrayList<Map<String, String>>();
    Map<String, String> responseMap = new HashMap<String, String>();

    List<String> fileNames = new ArrayList<String>();

    if (null != file) {
        // for (MultipartFile multipartFile : files) {

        String fileName = file.getOriginalFilename();
        fileNames.add(fileName);

        try {
            file.transferTo(new File("C:/" + file.getOriginalFilename()));
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    responseMap.put("displayText", file.getOriginalFilename());
    responseMap.put("fileSize", "" + file.getSize());
    response.add(responseMap);

    HttpHeaders httpHeaders = new HttpHeaders();
    httpHeaders.add("Accept", "application/json");
    return new ResponseEntity<List<Map<String, String>>>(response,
            httpHeaders, HttpStatus.OK);

}

User.java会像这样 -

@XmlRootElement(name = "User")


public class User implements Serializable { 
    private static final long serialVersionUID = 1L;

    private int userId;
    private String name;
    private String email;

    private String company;
    private String gender;

    //getter setter of the data members
}

根据我的理解,使用@RequestPart注释我希望根据其Content-Type评估XML多部分,最后将其解组到我的User类中(我使用的是Jaxb2,marshaller/unmarhaller已正确配置在当我将XML数据作为主体传递并使用@RequestBody注释时,应用程序上下文和过程适用于所有其他控制器方法.

但实际发生的是,尽管文件被正确地找到并解析为MultipartFile,但"用户"部分从未被看到,并且请求总是失败,与控制器方法签名不匹配.

我用几种客户端类型重现了这个问题,我相信多部分请求的格式是可以的.

请帮我解决这个问题,也许会有一些解决方法来接收混合/多部分请求.

感谢致敬,

Raghvendra

Answer 1

我设法解决了这个问题

端点示例：

@PostMapping("/")
public Document create(@RequestPart Document document,
                       @RequestPart(required = false) MultipartFile file) {
    log.debug("#create: document({}), file({})", delegation, file);
    //custom logic
    return document;
}

例外：

"error_message": "Content type 'application/octet-stream' not supported"

下一个方法引发异常：

org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver.readWithMessageConverters(HttpInputMessage,MethodParameter,Type)

解：

我们必须创建自定义转换器@Component，该转换器实现HttpMessageConverter或HttpMessageConverter并了解MediaType.APPLICATION_OCTET_STREAM。对于简单的解决方法，足以扩展AbstractJackson2HttpMessageConverter

@Component
public class MultipartJackson2HttpMessageConverter extends AbstractJackson2HttpMessageConverter {

/**
 * Converter for support http request with header Content-Type: multipart/form-data
 */
public MultipartJackson2HttpMessageConverter(ObjectMapper objectMapper) {
    super(objectMapper, MediaType.APPLICATION_OCTET_STREAM);
}

@Override
public boolean canWrite(Class<?> clazz, MediaType mediaType) {
    return false;
}

@Override
public boolean canWrite(Type type, Class<?> clazz, MediaType mediaType) {
    return false;
}

@Override
protected boolean canWrite(MediaType mediaType) {
    return false;
}
}

Answer 2

不确定你是否已经修复了你的问题,但是我也有一个类似的问题,当我将JSON对象与@RequestPart和MultipartFile混合在一起时,我的控制器没有把它拿起来.

您的通话方法签名看起来是正确的:

public ResponseEntity<List<Map<String, String>>> createUser(
        @RequestPart("file") MultipartFile file, @RequestPart(required=false) User user) {

// ... CODE ... 
}

但请确保您的请求看起来像这样:

POST /createUser
Content-Type: multipart/mixed; boundary=B0EC8D07-EBF1-4EA7-966C-E492A9F2C36E

--B0EC8D07-EBF1-4EA7-966C-E492A9F2C36E
Content-Disposition: form-data; name="user";
Content-Type: application/xml; charset=UTF-8

<user><!-- your user xml --></user>
--B0EC8D07-EBF1-4EA7-966C-E492A9F2C36E
Content-Disposition: form-data; name="file"; filename="A551A700-46D4-470A-86E7-52AD2B445847.dat"
Content-Type: application/octet-stream

/// FILE DATA
--B0EC8D07-EBF1-4EA7-966C-E492A9F2C36E--

Answer 3

你有没有尝试过

ResponseEntity<List<Map<String, String>>> createUser(
        @RequestPart("file") MultipartFile file, @RequestBody(required=false) User user) {

或者

ResponseEntity<List<Map<String, String>>> createUser(
        @RequestPart("file") MultipartFile file, @RequestParam(required=false) User user) {

如果这不起作用，你可以告诉我们吗mapping.xml