Spring REST Exception Handling FileUploadBase$SizeLimitExceededException - spring-rest

Question

I am using Spring Boot 1.5.3.RELEASE and using a Controller that takes a MultipartFile with some other information as arguments and returns a file.
Now I am facing the org.apache.tomcat.util.http.fileupload.FileUploadBase$SizeLimitExceededException when the file exceeds the maximum Sizes.
spring.http.multipart.maxFileSize=17728640
spring.http.multipart.maxRequestSize=17728640
This works well but i need a custom Response and actually the Exception is throwed only at server side before the method call.
Can anyone tell me how can I define a Custom Error Handler that handles this exception and response something like ResponseEntity.status(HttpStatus.CONFLICT).body("size_exceeded")
My Method:
#SuppressWarnings("rawtypes")
#RequestMapping(value = "/{Id}/attachments", method = RequestMethod.POST)
public ResponseEntity addTaskAttachment(#RequestParam("file") MultipartFile file, #PathVariable Long Id,
#CurrentUser User currentUser) {
// Some code here
ResponseEntity.status(HttpStatus.OK).body(attachmentAsByteArray);
}

Answer 1

You are correct in your observation that an Exception Handler with #RestControllerAdvice wouldn't work for multi part exceptions and reason being MultipartFile parsing & validation step preceding the mapping resolver step.
As advised in first accepted answer by geoand for this SO question here , you need to define and register an ErrorController.
Also, note that as already mentioned in that answer , Spring Boot already defines a BasicErrorController that you can extend to add new content types to return a JSON etc ( since default is text/html ) by adding a new public method with #RequestMapping & #Produces .