Spring-boot upload file MultiPartFile cannot obtain file problem

1. The phenomenon is added in spring-bootcommons-fileupload jar and mutilPart bean is configured. After the POST request of upload, it is found that

("file")=null，A little strange，Only after checking the documents。

 <bean  class="">
        <property name="maxUploadSize" value="104857600"/>
        <property name="maxInMemorySize" value="4096"/>
    </bean>

2. The reason is: spring-boot comes withorg..MultipartFile
There is a conflict with Multipart. If MultipartResolver and ServletFileUpload are used at the same time, it will return false in (). Then the entire loop will jump out. The reason for the entire problem is that the Spring framework first called MultipartResolver to handle http multi-part requests. The http multipart request here has been consumed. Then it is handed over to ServletFileUpload, so ServletFileUpload cannot obtain the corresponding multi-part request. Therefore, the multipartResolve configuration is removed and the problem is solved.

3. For a single file, only one variable is needed. If multiple files are uploaded, change the MultipartFile to an array, and then upload and save it separately.

@RequestMapping(value="/multipleSave", method= )
    public @ResponseBody String multipleSave(@RequestParam("file") MultipartFile[] files){
        String fileName = null;
    	String msg = "";
    	if (files != null &&  >0) {
    		for(int i =0 ;i< ; i++){
	            try {
	                fileName = files[i].getOriginalFilename();
	                byte[] bytes = files[i].getBytes();
	                BufferedOutputStream buffStream = 
	                        new BufferedOutputStream(new FileOutputStream(new File("/tmp/" + fileName)));
	                (bytes);
	                ();
	                msg += "You have successfully uploaded " + fileName";
	            } catch (Exception e) {
	                return "You failed to upload " + fileName + ": " + ();
	            }
    		}
    		return msg;
        } else {
            return "Unable to upload. File is empty.";
        }
    }
}

-boot configures maximum limits for uploading and requesting files:
Directly in
=128KB
=128KB

5. spring-boot-starter-web are already added as dependencies. To upload files with Servlet containers, you need to register aMultipartConfigElement class (which would be <multipart-config> in ). Thanks to Spring Boot, everything is auto-configured for you! spring-boot-upload link