CODEWITHSUNDEEP
javaspring-bootrestmultipartform-data
Jason
Jason

Reputation: 2915

Notifying user of large file upload

I have a REST API implemented through Spring Boot. I need to serve multipart/form-data requests (a JSON and a list of images) and I do so through this simple controller method:

@PostMapping(value = "/products", consumes = MediaType.MULTIPART_FORM_DATA_VALUE )
public ResponseEntity<ResponseMessage> postProduct(@NonNull @RequestPart(value = "request") final MyJsonBody postRequest,
                                                   @NonNull @RequestPart(value = "files") final List<MultipartFile> files)
{
    validateFileTypes(files);
    log.info("Request id and name fields: " + postRequest.getProductId() + ", " + postRequest.getProductName() + ".");
    log.info("Received a total of: " + files.size()  + " files.");
    storeFiles(files);
    return success("Request processed!", null, HttpStatus.OK);
}

To constrain the size of the uploaded files, I have the following in my application.properties:

# Constrain maximum sizes of files and requests
spring.http.multipart.max-file-size=20MB
spring.http.multipart.max-request-size=110MB

I tested the behavior of these keys by uploading a big file, and while they work well, the returned message to the user is not particularly informative of what happened:

{
    "timestamp": "2021-01-05T14:07:14.577+00:00",
    "status": 500,
    "error": "Internal Server Error",
    "message": "",
    "path": "/rest/products"
}

Is there any way for me to have SpringBoot automatically supply a message in the case of too large of a file uploaded, or can I only do this through my own custom controller logic in the postProduct method shown above?

Upvotes: 0

Views: 212

Answers (1)

Matheus
Matheus

Reputation: 3370

You need to handle MaxUploadSizeExceededException by using either a HandleExceptionResolver or a ControllerAdvice (or a RestControllerAdvice).

Something like this:

@RestControllerAdvice
public class CustomExceptionHandler {

    @ExceptionHandler({
        MaxUploadSizeExceededException.class
    })
    public ResponseEntity<Object> handleMaxUploadSizeExceededException(MaxUploadSizeExceededException ex) {
        Map<String, Object> body = new HashMap<>();
        body.put("message", String.format("Max upload limit exceeded. Max upload size is %d", ex.getMaxUploadSize()));

        return ResponseEntity.unprocessableEntity().body(body);
    }

}

Upvotes: 1

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