public boolean hasEnoughSpaceOnSdCard(long updateSize) {
       String status = Environment.getExternalStorageState();
       if (!status.equals(Environment.MEDIA_MOUNTED)) {
           return false;
       }
       File path = Environment.getExternalStorageDirectory();
       StatFs stat = new StatFs(path.getPath());
       long blockSize = stat.getBlockSize();
       long availableBlocks = stat.getAvailableBlocks();
       return (updateSize < availableBlocks * blockSize);
   }