如何在Spring MVC中同时使用多部分/表单和分块编码来接收文件上传？

Z时代
2024-01-10
分类：问答

我正在尝试编写一个可以接收multipart / form或传输编码的分块文件上传的spring

mvc方法。我可以编写一个单独的方法来处理每种类型，但是我想用相同的方法来做，所以我可以使用相同的REST POST uri，例如：

http://host:8084/attachments/testupload

到目前为止，这是我最好的尝试：

@RequestMapping(value = { "/testupload" }, method = RequestMethod.POST, produces = 
  "application/json")
public @ResponseBody
ResponseEntity<MessageResponseModel> testUpload(
  @RequestParam(value = "filedata", required = false) MultipartFile filedata,
  final HttpServletRequest request) throws IOException {
  InputStream is = null;
  if (filedata == null) {
    is = request.getInputStream();
  }
  else {
    is = filedata.getInputStream();
  }
  byte[] bytes = IOUtils.toByteArray(is);
  System.out.println("read " + bytes.length + " bytes.");
  return new ResponseEntity<MessageResponseModel>(null, null, HttpStatus.OK);
}

使用上面的方法，我可以上传一个多部分文件，但是如果我上传了一个分块的文件，我会从spring中得到一个异常，内容为：

org.springframework.web.multipart.MultipartException: \ The current request is not a multipart request

如果删除MultipartFile请求参数，则非常适合分块传输编码。如果我将其保留，则非常适合MultipartFile上传。如何使用相同的方法来处理两种上传类型？

这适用于分块：

@RequestMapping(value = { "/testupload" }, method = RequestMethod.POST, produces = 
  "application/json")
public @ResponseBody
ResponseEntity<MessageResponseModel> testUpload(
  final HttpServletRequest request) throws IOException {
  InputStream is = null;
  is = request.getInputStream();
  byte[] bytes = IOUtils.toByteArray(is);
  System.out.println("read " + bytes.length + " bytes.");
  return new ResponseEntity<MessageResponseModel>(null, null, HttpStatus.OK);
}

这对MultipartFile非常有用：

@RequestMapping(value = { "/testupload" }, method = RequestMethod.POST, produces = 
  "application/json")
public @ResponseBody
ResponseEntity<MessageResponseModel> testUpload(
  @RequestParam MultipartFile filedata) throws IOException {
  InputStream is = null;
  is = filedata.getInputStream();
  byte[] bytes = IOUtils.toByteArray(is);
  System.out.println("read " + bytes.length + " bytes.");
  return new ResponseEntity<MessageResponseModel>(null, null, HttpStatus.OK);
}

应该有可能，有人知道该怎么做吗？

谢谢史蒂夫

回答：

我的代码节选（Spring 3.2，使用AngularJS上传blueimp文件）：

/**
 * Handles chunked file upload, when file exceeds defined chunked size.
 * 
 * This method is also called by modern browsers and IE >= 10
 */
@RequestMapping(value = "/content-files/upload/", method = RequestMethod.POST, headers = "content-type!=multipart/form-data")
@ResponseBody
public UploadedFile uploadChunked(
        final HttpServletRequest request,
        final HttpServletResponse response) {
    request.getHeader("content-range");//Content-Range:bytes 737280-819199/845769
    request.getHeader("content-length"); //845769
    request.getHeader("content-disposition"); // Content-Disposition:attachment; filename="Screenshot%20from%202012-12-19%2017:28:01.png"
    request.getInputStream(); //actual content.
    //Regex for content range: Pattern.compile("bytes ([0-9]+)-([0-9]+)/([0-9]+)");
    //Regex for filename: Pattern.compile("(?<=filename=\").*?(?=\")");
    //return whatever you want to json
    return new UploadedFile();
}
/**
 * Default Multipart file upload. This method should be invoked only by those that do not
 * support chunked upload.
 * 
 * If browser supports chunked upload, and file is smaller than chunk, it will invoke
 * uploadChunked() method instead.
 * 
 * This is instead a fallback method for IE <=9
 */
@RequestMapping(value = "/content-files/upload/", method = RequestMethod.POST, headers = "content-type=multipart/form-data")
@ResponseBody
public HttpEntity<UploadedFile> uploadMultipart(
        final HttpServletRequest request,
        final HttpServletResponse response,
        @RequestParam("file") final MultipartFile multiPart) {
    //handle regular MultipartFile
    // IE <=9 offers to save file, if it is returned as json, so set content type to plain.
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.TEXT_PLAIN);
    return new HttpEntity<>(new UploadedFile(), headers);
}