Jersey 2 Multipart upload Client

I want to write a simple jersey 2 client to upload a file. I'm using Jersey 2.10.1 and wrote following server code:

@POST
@Consumes(MediaType.MULTIPART_FORM_DATA)
@Produces(MediaType.APPLICATION_JSON)
public Response uploadFile(
        @FormDataParam("file") InputStream aUploadedInputStream,
        @FormDataParam("file") FormDataContentDisposition aFileDetail) {

    UploadedFile uploadedFile = new UploadedFile();
    uploadedFile.setOriginalFileName(aFileDetail.getFileName());
    uploadedFile.setFileSize(aFileDetail.getSize());
    saveToFile(aUploadedInputStream, aFileDetail.getType(), uploadedFile);
    databaseHelper.saveInDatabase(uploadedFile);

    return Response.status(200).build();
}

("UploadedFile" is an custom class to save the information of the file in a database)

And this is my client code:

private static final String TARGET_URL = "http://localhost:49158/rest/service/upload";

public Slimclient() {
    Client client = ClientBuilder.newBuilder()
            .register(MultiPartFeature.class).build();
    WebTarget webTarget = client.target(TARGET_URL);
    MultiPart multiPart = new MultiPart();

    FileDataBodyPart fileDataBodyPart = new FileDataBodyPart("file",
            new File("C:/Users/Nicklas2751/Desktop/test.txt"), MediaType.APPLICATION_OCTET_STREAM_TYPE);
    multiPart.bodyPart(fileDataBodyPart);

    Response response = webTarget.request(
            MediaType.MULTIPART_FORM_DATA).post(
            Entity.entity(multiPart, multiPart.getMediaType()));

    System.out.println(response.getStatus()+" "+response.getStatusInfo()+" "+response);
}

public static void main(String[] args) {
    new Slimclient();
}

The server code runs without any problems but when i run the client i get the following error:

415 Unsupported Media Type InboundJaxrsResponse{ClientResponse{method=POST, uri=http://localhost:49158/rest/service/upload, status=415, reason=Unsupported Media Type}}

I searched the web for a good tutorial for jersey 2 and multipart fileupload but i can only find tutorials and examples for jersey 1 or with an HTML-Form as "Client". I hope sombody can help me :)

I've found my problem. I've missed to set the MediaType of the MultiPart and with the .request(MediaType.MULTIPART_FORM_DATA) I've set the expected MediaType of the response to MULTIPART_FORM_DATA. Here is the working code:

public class Slimclient {
    private static final String TARGET_URL = "http://localhost:49158/rest/service/upload";

    public Slimclient() {
        Client client = ClientBuilder.newBuilder()
            .register(MultiPartFeature.class).build();
        WebTarget webTarget = client.target(TARGET_URL);
        MultiPart multiPart = new MultiPart();
        multiPart.setMediaType(MediaType.MULTIPART_FORM_DATA_TYPE);

        FileDataBodyPart fileDataBodyPart = new FileDataBodyPart("file",
            new File("C:/Users/Nicklas/Desktop/aab.txt"),
            MediaType.APPLICATION_OCTET_STREAM_TYPE);
        multiPart.bodyPart(fileDataBodyPart);

        Response response = webTarget.request(MediaType.APPLICATION_JSON_TYPE)
            .post(Entity.entity(multiPart, multiPart.getMediaType()));

        System.out.println(response.getStatus() + " "
            + response.getStatusInfo() + " " + response);
    }

    public static void main(String[] args) {
        new Slimclient();
    }
}