دانلود فایل از سرور

 کد کلاس دانلود:

 public static void download(final String downloadPath, final String filePath, 
                                                     final OnProgressDownloadListener listener) {

        Thread thread = new Thread(new Runnable() {

            @Override
            public void run() {
                try {
                    URL url = new URL(downloadPath);
                    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setDoOutput(true);
                    connection.connect();

                    final int fileSize = connection.getContentLength();
                    int downloadSize = 0;

                    File file = new File(filePath);
                    if (file.exists()) {
                        file.delete();
                    }

                    FileOutputStream outputStream = new FileOutputStream(filePath);

                    InputStream inputStream = connection.getInputStream();
                    byte[] buffer = new byte[G.DOWNLOAD_BUFFER_SIZE];
                    int len = 0;
                    while ((len = inputStream.read(buffer)) > 0) {

                        outputStream.write(buffer, 0, len);
                        downloadSize += len;
                        final float downloadPercent = 100.0f * ((float) downloadSize / fileSize);
                        if (listener != null) {
                            final int finalDownloadSize = downloadSize;
                            G.handler.post(new Runnable() {

                                @Override
                                public void run() {
                                    listener.onProgressDownload((int) downloadPercent, finalDownloadSize, fileSize);

                                }
                            });
                        }
                    }

                }
                catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
        thread.start();

    }