ajax - Spring mvc 使用 AJAX 一次上传多个文件不起作用

Question

我正在使用 Spring boot 2.0.1，我正在尝试使用 dropzone 上传多个文件。当我在 Dropzone.js 上使用 uploadMultiple: false 时，一切工作正常。当我设置 uploadMultiple: true 时，我的 Controller 停止工作。

Controller 类如下:

@PostMapping(value = "/img/upload")
public ResponseEntity<?> fileUpload(@RequestParam("file") MultipartFile[] files){

    System.out.println(files.length);
    for (MultipartFile file : files) {
        try {
            file.transferTo(new File("/opt/img/" + file.getOriginalFilename()));
            System.out.println(file.getOriginalFilename());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    return new ResponseEntity<>("File Uploaded Successfully.", HttpStatus.OK);
}

文件不超过1MB，我的设置是

spring.servlet.multipart.max-file-size=10MB
spring.servlet.multipart.max-request-size=10MB

上传文件时的请求头:

------WebKitFormBoundaryihPcX9WHR5UA9jGD
Content-Disposition: form-data; name="file[0]"; filename="cars-02-01.png"
Content-Type: image/png


------WebKitFormBoundaryihPcX9WHR5UA9jGD
Content-Disposition: form-data; name="file[1]"; filename="Screenshot from 2018-05-03 23-31-53.jpg"
Content-Type: image/jpeg

一切看起来都很完美。我还是找不到这个问题的原因？

Answer 1

看来我应该使用 MultipartHttpServletRequest 而不是 MultipartFile[] 文件。我将方法更改为:

@PostMapping(value = "/img/upload")
public ResponseEntity<?> fileUpload(MultipartHttpServletRequest request) {
    Map<String, MultipartFile> fileMap = request.getFileMap();

    for (MultipartFile file : fileMap.values()) {
        try {
            file.transferTo(new File("/opt/img/" + file.getOriginalFilename()));
            System.out.println(file.getOriginalFilename());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return new ResponseEntity<>("File Uploaded Successfully.", HttpStatus.OK);
}