java - How to process a multipart request consisting of a file and a JSON object in Spring restful service?

Question

I have the following resource (implemented using Spring 4.05.RELEASE) which accepts a file and a JSON object:

(P.S. activityTemplate is a serializable entity class)

...
@RequestMapping(value="/create", method=RequestMethod.POST)
public @ResponseBody ActivityTemplate createActivityTemplate(
        @RequestPart ActivityTemplate activityTemplate, @RequestPart MultipartFile jarFile)
{
   //process the file and JSON
}
...

and this is the form I am testing from:

<form method="POST" enctype="multipart/form-data"
    action="http://localhost:8080/activityTemplates/create">
    JSON: <input type="text" name="activityTemplate" value='/* the JSON object*/'><br />

    File to upload: <input type="file" name="file">
    <input type="submit" value="Upload">
</form>

and this is the error that I get:

 There was an unexpected error (type=Unsupported Media Type, status=415).
 Content type 'application/octet-stream' not supported

So how should I make the resource accept the JSON object as part of the multipart request, or should I be sending the form in a different way?

Answer 1

This took me two days to work for me!

client (angular):

$scope.saveForm = function () {
      var formData = new FormData();
      var file = $scope.myFile;
      var json = $scope.myJson;
      formData.append("file", file);
      formData.append("ad",JSON.stringify(json));//important: convert to string JSON!
      var req = {
        url: '/upload',
        method: 'POST',
        headers: {'Content-Type': undefined},
        data: formData,
        transformRequest: function (data, headersGetterFunction) {
          return data;
        }
      };

Spring (Boot):

@RequestMapping(value = "/upload", method = RequestMethod.POST)
    public @ResponseBody
    Advertisement storeAd(@RequestPart("ad") String adString, @RequestPart("file") MultipartFile file) throws IOException {

        Advertisement jsonAd = new ObjectMapper().readValue(adString, Advertisement.class);
//do whatever you want with your file and jsonAd