Why am I getting a 415 Unsupported Media Type ?

[tangara goh]

I have this end point which will take in a petId and a Multipart file but no matter how I tried in postman, I just get

this error :

'timestamp" : "asdfadsfa",
"status" : 415,
"error" : "Unsupported Media Type",
"message": "",
"path": "/pet/2/uploadImage"

Here's my code:

It is tweaked from

//https://www.callicoder.com/spring-boot-file-upload-download-rest-api-example/

as suggested from my 'mentor'

	@RequestMapping(value = "/{petId}/uploadImage", method = RequestMethod.POST ,consumes = "multiplpart/form-data", produces = MediaType.APPLCATION_JSON_VALUE)
	public ResponseEntity<byte[]> uploadImage( @PathVariable Integer petId, @RequestPart("file") MultipartFile file ) throws IOException{ 
		System.out.println("GET uploadImage with petId ENDPOINT1" + petId);
		logger.debug("Updating pet with image: {}", (Throwable) file); 		
		System.out.println("file" + file.getOriginalFilename());
		String fileName = fileStorageService.storeFile(file);
		boolean condition = false;
		for (Pet p : pets) { // there is a List<Pet>pets above this code
			if (p.getId().equals(petId)) {
				if (!file.isEmpty()) {
					fileStorageService.storeFile(file);	//don't think can use this one here
//					byte[] fileContent = Files.readFileToByteArray(file);
//			        String encodedString = Base64
//			          .getEncoder()
//			          .encodeToString(fileContent);
//			        //byte[] bytes = file.getBytes();
			        //Path path = Paths.get(UPLOADED_FOLDER + file.getOriginalFilename());
			        //Files.write(path, bytes);
				 return new ResponseEntity<byte[]>(file.getBytes(), HttpStatus.OK);
				//return new UploadFileResponse<Void>(HttpStatus.ACCEPTED);// 202;
			}
		}
		
	}
		return new ResponseEntity("Successfully uploaded!", HttpStatus.OK);
	}}

I also tried to use ResponseEntity<UploadFileResponse> like what the sample code did, without success.

Then, I tried to convert it into Base64 and changed to produces produces = MediaType.JPGE , also not successful but obviously for this uescase they are looking for a file as Json.

Another thing I noticed is that, there is no print out of

GET uploadImage with petId ENDPOINT1" + petId

so I wonder if did get into the method at all.

The console shows the following error :

org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'multipart/form-data, boundary = ----------a bunch of digits' not supported]

I hope some one can point out what is wrong.

BTW, the is a pet before petId/uploadImage route.

[Rob Spoor]

tangara goh wrote:

org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'multipart/form-data, boundary = ----------a bunch of digits' not supported]

How did that content type get created? Because the format is wrong; instead of multipart/form-data, boundary = ----------a bunch of digits' not supported it should be multipart/form-data; boundary = ----------a bunch of digits' not supported. In other words, between multipart/form-data and the boundary there should be a semi-colon, not a comma.

I'd also suggest not to use a boundary that start with any dashes, because multipart/form-data bodies use two dashes to indicate the start of new parts, and the end of the overall body. And I don't know if the spaces around the = are actually supported; I never add them.

[Tim Holloway]

There should be an API method for MIME-encoding response and that API would be responsible for both the Base64 encoding and wrapping the MIME identification headers around the encoded data.

The original Internet was required to be wholly text-based, since the types of machines and OS's that data could traverse varied considerably in byte size and endian-ness. So MIME was developed to allow binary data to travel safely over a text transport. In other words, MIME is very old, and very well supported.

In fact, let me quote the JavaDocs:

javax.servlet.ServletResponse wrote:
To send binary data in a MIME body response, use the ServletOutputStream returned by getOutputStream(). To send character data, use the PrintWriter object returned by getWriter(). To mix binary and text data, for example, to create a multipart response, use a ServletOutputStream and manage the character sections manually.

In the case of Spring, expect that there should be Spring services to make the job even easier so you don't have to do all that stuff manually, but that's what the underlying logic should rely on.

[tangara goh]

Tim Holloway wrote:There should be an API method for MIME-encoding response and that API would be responsible for both the Base64 encoding and wrapping the MIME identification headers around the encoded data.



In the case of Spring, expect that there should be Spring services to make the job even easier so you don't have to do all that stuff manually, but that's what the underlying logic should rely on.

Hi Tim,

Could you let me know specifically what is the specific Spring API that I can make use of that can work with java.io.Files ?

Because I tried InputStream and OutputStream but I am not able to get image inserted. So, am not sure if I am using the right API.

InputStream inputStream = new BufferedInputStream(file.getInputStream());
Path Location = Paths.get(path); // here it refers to my function to get the file path
OutputStream os = Files.newOutputStream(Pathsget(Locaiton.toString(), file.getOriginalFilename()));

Furthermore, I am not able to get a json output when using Postman...all it is returning is {}...(maybe this has to be posted as another question).

I hope you can advise me on the above.

Tks.