Payload too large error (413) when uploading using JS Fetch API. Works fine via Postman

Question

I have a multipart upload API that works flawlessly when I upload a file via Postman. However, when I upload via the same API but using Fetch API, I get 413 error.

I tried the solution given here but it did not work.

My JS code is as follows -

async function uploadAudio(formElements) {

    const formData = new FormData();
    const file = fileUploadField.files[0];
    formData.append("file", file);

    console.log("Name: " + file.name); // Prints the correct file name
    console.log("Size: " + file.size); // Prints the correct size (which is < than what is set server side)

    const options = {
          method: 'POST',
          body: formData,
          headers: {
            'Content-Type': 'multipart/form-data',
            'Accept': 'application/json',
            'Authorization': 'Bearer ' + authTokenArr[0]
          }
        };

    const response = await fetch(base_url + "/audio/file", options);
    const data = await response.json();

    if (response.ok) {
        handleSuccess(data);
    } else {
        handleFail(data);
    }
} 

application.properties file -

# max file size
spring.servlet.multipart.max-file-size=10MB
# max request size
spring.servlet.multipart.max-request-size=10MB 

REST controller -

@PostMapping("file", produces = [ProduceTypes.JSON])
    fun uploadAudio(@RequestParam("file") file: MultipartFile,
                      @RequestHeader (name="Authorization") token: String): ResponseEntity<MutableMap<String, Any>> {

        val user: User = userService.getUserDetailsByToken(token)

        val body: MutableMap<String, Any> = LinkedHashMap()
        body["status"] = ApiStatus.UPLOADED
        body["fileId"] = podcastFileService.uploadFileToB2(user, file)

        return ResponseEntity(body, HttpStatus.CREATED)
    }

Here is my server side log -

2020-09-03 18:56:02.288 DEBUG 40716 --- [nio-8080-exec-7] o.s.web.servlet.DispatcherServlet        : POST "/audio/file", parameters={}
2020-09-03 18:56:02.293 DEBUG 40716 --- [nio-8080-exec-7] .m.m.a.ExceptionHandlerExceptionResolver : Using @ExceptionHandler com.krtkush.audiotime.globalexceptions.GlobalExceptionHandler#handleMultipartException(MultipartException)
2020-09-03 18:56:02.356 DEBUG 40716 --- [nio-8080-exec-7] o.s.w.s.m.m.a.HttpEntityMethodProcessor  : Using 'application/json', given [application/json] and supported [application/json, application/*+json, application/json, application/*+json]
2020-09-03 18:56:02.357 DEBUG 40716 --- [nio-8080-exec-7] o.s.w.s.m.m.a.HttpEntityMethodProcessor  : Writing [{timestamp=2020-09-03T18:56:02.297867, message=Maximum file size acceptable is 10MB}]
2020-09-03 18:56:02.364 DEBUG 40716 --- [nio-8080-exec-7] .m.m.a.ExceptionHandlerExceptionResolver : Resolved [org.springframework.web.multipart.MultipartException: Failed to parse multipart servlet request; nested exception is java.io.IOException: org.apache.tomcat.util.http.fileupload.FileUploadException: the request was rejected because no multipart boundary was found]
2020-09-03 18:56:02.364 DEBUG 40716 --- [nio-8080-exec-7] o.s.web.servlet.DispatcherServlet        : Completed 413 PAYLOAD_TOO_LARGE

Why would there be a size problem when the API is working fine via Postman and even when uploaded using mustache template with a non-REST controller.

Answer 1

Turns out 'Content-Type': 'multipart/form-data' was the problem. It worked when I removed it. Comment by @Kostiantyn here helped me out.