private void uploadSkinFile(String url) throws Exception {
        try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
            HttpPost httppost = new HttpPost(url);

            StringBody user = new StringBody(this.username, ContentType.TEXT_PLAIN);
            StringBody sess = new StringBody(this.session, ContentType.TEXT_PLAIN);

            HttpEntity reqEntity = MultipartEntityBuilder.create()
                    .addPart("user", user)
                    .addPart("sessionId", sess)
                    .build();


            httppost.setEntity(reqEntity);

            try (CloseableHttpResponse response = httpclient.execute(httppost)) {
                System.out.println(response.getStatusLine());
                HttpEntity resEntity = response.getEntity();
                if (resEntity != null) {
                    String resString = EntityUtils.toString(resEntity);
                    if (resString.equals("OK")) {
                        publish(new SkinRemoveState(true));
                    } else {
                        publish(new SkinRemoveState(false));
                    }
                }
                
                EntityUtils.consume(resEntity);
            }
        }
    }