spring boot file uploading executes twice when MultipartException occurs - file-upload

Question

I want to upload files using spring-boot, and I have configured the properties right, and I also ensure the controller is correct, but the strange thing is the controller executed twice when I tried to upload a file larger exceed the limitation, what I expect is an error json message, and what I got is no response under the Postman.
Here is my controller,
#RestController
public class FileUploadController implements HandlerExceptionResolver {
private static final Logger LOGGER = LoggerFactory.getLogger(FileUploadController.class);
private static final String UPLOAD_PATH = "upload";
#ResponseBody
#RequestMapping(value = "/upload", method = RequestMethod.POST, consumes = "multipart/form-data", produces = "application/json;charset=UTF-8")
public String upload(final MultipartFile file) {
try {
final Result<String> result = new Result<>();
if (file.isEmpty()) {
result.setSuccess(false);
result.setMessage("file is empty");
return Constants.OBJECT_MAPPER.writeValueAsString(result);
}
final File outputFile = new File(UPLOAD_PATH, UUID.randomUUID().toString());
FileUtils.writeByteArrayToFile(outputFile, file.getBytes());
result.setSuccess(true);
result.setMessage(outputFile.toString());
return Constants.OBJECT_MAPPER.writeValueAsString(result);
} catch (final Exception ex) {
LOGGER.error(ex.getMessage(), ex);
return ExceptionResultBuilder.build(ex);
}
}
#Override
public ModelAndView resolveException(final HttpServletRequest request, final HttpServletResponse response, final Object handler, final Exception ex) {
final ModelAndView modelAndView = new ModelAndView();
modelAndView.setView(new MappingJackson2JsonView());
final Map<String, Object> map = new HashMap<>();
map.put("success", false);
if (ex instanceof MultipartException) {
// if (LOGGER.isDebugEnabled()) {
LOGGER.info(ex.getMessage(), ex);
// }
final Throwable rootCause = ((MultipartException) ex).getRootCause();
if (rootCause instanceof SizeLimitExceededException) {
map.put("message", "request too large");
} else if (rootCause instanceof FileSizeLimitExceededException) {
map.put("message", "file too large");
} else {
map.put("message", "其他异常: " + rootCause.getMessage());
}
} else {
LOGGER.error(ex.getMessage(), ex);
}
modelAndView.addAllObjects(map);
return modelAndView;
}
}
and this is my property snippet for file uploading,
# MULTIPART (MultipartProperties)
multipart.enabled=true
multipart.max-file-size=5Mb
multipart.max-request-size=10Mb
If I tried to upload a file a bit larger than 5M, I will get the result like below under Postman, (the file size is 5208k)
enter image description here
and if I tried to upload a file between 5M and 10M, I will get this error, (the file size is 9748k)
enter image description here
I debugged into the controller and found that the resolveException method executed twice in a single upload.
Does anybody give me some tip?

Answer 1

The latest code list here, and I still got the same result,
#RestController
#ControllerAdvice
public class FileUploadController {
private static final Logger LOGGER = LoggerFactory.getLogger(FileUploadController.class);
private static final String UPLOAD_PATH = "upload";
#RequestMapping(value = "/upload", method = RequestMethod.POST, consumes = "multipart/form-data", produces = "application/json;charset=UTF-8")
public HttpEntity<?> upload(final MultipartFile file) {
try {
final Result<String> result = new Result<>();
if (file == null || file.isEmpty()) {
result.setSuccess(false);
result.setMessage("上传的文件为空");
return new ResponseEntity<Result<?>>(result, HttpStatus.OK);
}
final File outputFile = new File(UPLOAD_PATH, UUID.randomUUID().toString());
FileUtils.writeByteArrayToFile(outputFile, file.getBytes());
result.setSuccess(true);
result.setMessage(outputFile.toString());
return new ResponseEntity<Result<?>>(result, HttpStatus.OK);
} catch (final Exception ex) {
LOGGER.error(ex.getMessage(), ex);
return ExceptionResultBuilder.build(ex);
}
}
#ExceptionHandler(MultipartException.class)
public HttpEntity<?> multipartExceptionHandler(final MultipartException exception) {
LOGGER.error(exception.getMessage(), exception);
try {
final Result<String> result = new Result<>();
result.setSuccess(false);
final Throwable rootCause = ((MultipartException) exception).getRootCause();
if (rootCause instanceof SizeLimitExceededException) {
result.setMessage("请求过大");
} else if (rootCause instanceof FileSizeLimitExceededException) {
result.setMessage("文件过大");
} else {
result.setMessage("未知错误");
}
return new ResponseEntity<Result<?>>(result, HttpStatus.OK);
} catch (final Exception ex) {
LOGGER.error(ex.getMessage(), ex);
return ExceptionResultBuilder.build(ex);
}
}
}

Answer 2

I just go the same error and fix it by add the flowing code to my controller, good luck
#ExceptionHandler({ MultipartException.class, FileSizeLimitExceededException.class,
SizeLimitExceededException.class })
public ResponseEntity<Attachment> handleUploadrException(HttpServletRequest request, Throwable ex) {
Attachment result = new Attachment();
result.setDescription(ex.getMessage());
HttpStatus status = getStatus(request);
return new ResponseEntity<Attachment>(result, status);
}
private HttpStatus getStatus(HttpServletRequest request) {
Integer statusCode = (Integer) request.getAttribute("javax.servlet.error.status_code");
if (statusCode == null) {
return HttpStatus.INTERNAL_SERVER_ERROR;
}
return HttpStatus.valueOf(statusCode);
}