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 

Answer 2

Hope this should help you. You need to set the boundary in your request to inform the HTTP Request. is simple; A brief introduction to the multipart format can be found in the below link

HTML 4.01 Specification for multipart

The following example illustrates "multipart/form-data" encoding. If the Json Object is "MyJsonObj" , and file that need to be send is "myfile.txt", the user agent might send back the following data:

Content-Type: multipart/form-data; boundary=MyBoundary  --MyBoundary Content-Disposition: form-data; name="myJsonString" Content-Type: application/json  MyJsonObj //Your Json Object goes here --MyBoundary Content-Disposition: form-data; name="files"; filename="myfile.txt" Content-Type: text/plain  ... contents of myfile.txt ... --MyBoundary-- 

or if your files is of type image with name "image.gif" then,

--MyBoundary Content-Disposition: file; filename="image.gif" Content-Type: image/gif Content-Transfer-Encoding: binary  ...contents of image.gif... --MyBoundary-- 

You specify boundary in the Content-Type header so that the server knows how to split the data sent.

So, you basically need to select a boundary value to:

• Use a value that won't appear in the HTTP data sent to the server like 'AaB03x'.
• Be consistent and use the same value all over the request.