upload an image from the link to the gallery

Question

I'm trying to download the image from the link to the gallery

this codes not working

RxVolley.download(FileUtils.getSDCardPath() + "/Wallpaper/" + System.currentTimeMillis() + ".png"
                        , "http://......"
                        , new ProgressListener() {
                            @Override
                            public void onProgress(long transferredBytes, long totalSize) {

                            }
                        }, new HttpCallback() {
                            @Override
                            public void onSuccess(String t) {
                                Toast.makeText(context, "下载成功", Toast.LENGTH_SHORT).show();
                            }

                            @Override
                            public void onFailure(VolleyError error) {
                                Toast.makeText(context, "下载失败", Toast.LENGTH_SHORT).show();
                            }
                        });

are there other codes working for example asycn task etc... , I hope help me