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，并且正在尝试使用 dropzone 上传多个文件。当我使用 uploadMultiple: falseon时，一切都运行良好Dropzone.js。当我设置uploadMultiple: true时，我的控制器停止工作。

控制器类如下：

@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

上传文件时的请求标头：

------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

一切似乎都很完美。我仍然找不到这个问题的原因？

Answer 1

看来我应该使用MultipartHttpServletRequest而不是MultipartFile[] files. 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);
}