Ion

public void getUploadPostImageApi(int postId) {

        final ProgressDialog progressDialog = new ProgressDialog(this);
        progressDialog.setCancelable(false);
        progressDialog.setMessage("Uploading...");
        progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        progressDialog.setProgressNumberFormat("%1d MB / %2d MB");
        progressDialog.show();

        ArrayList<Part> filesParts = new ArrayList<>();
        for(String path: imageList)
        {
            Log.i("Check Path ", path);
            filesParts.add(new FilePart("avatar", new File(path)));
        }

        Ion.with(this)
                .load(API_Config.API_DOMAIN() + "api/file/UploadPostImages")
                .uploadProgressHandler(new ProgressCallback() {
                    @Override
                    public void onProgress(long uploaded, long total) {
                        // Displays the progress bar for the first time.

                        Log.i("Check Upload", uploaded+"/"+total);

                        if((int) uploaded == (int) total)
                        {
                            progressDialog.incrementProgressBy((int) byteToMB(uploaded));
                        }
                        else
                        {
                            progressDialog.setProgress((int) byteToMB(uploaded));
                            progressDialog.setMax((int) byteToMB(total));
                        }

                    }
                })
                .setTimeout(60 * 60 * 1000)
                .setHeader("Authorization", AppController.getInstance().getAccessToken())
                .setMultipartParameter("PostId", String.valueOf(postId))
                .addMultipartParts(filesParts)
                .asJsonObject()
                        // run a callback on completion
                .setCallback(new FutureCallback<JsonObject>() {
                    @Override
                    public void onCompleted(Exception e, JsonObject result) {

                        if (progressDialog.isShowing())
                            progressDialog.dismiss();

                        try {
                            JSONObject object = new JSONObject(result.toString());
                            Toast.makeText(AddFeedActivity.this, object.getString("error_description"), Toast.LENGTH_LONG).show();
                        } catch (JSONException f) {
                            f.printStackTrace();
                        } catch (NullPointerException a) {
                            Toast.makeText(AddFeedActivity.this, "Something went wrong", Toast.LENGTH_LONG).show();
                        }

                        onBackPressed();
                    }
                });
    }