@Override
 public File doInBackgroundWithException(Object... params) throws Exception {
   Log.t("... start extracting file", zipFile);
   ZipFile zf = new ZipFile(zipFile);
   Enumeration<? extends ZipEntry> e = zf.entries();
   long totalUncompressedSize = 0;
   while (e.hasMoreElements()) {
     ZipEntry ze = e.nextElement();
     totalUncompressedSize += ze.getSize();
   }
   zf.close();
   if (totalUncompressedSize > 0) setTotalUncompressedSize(totalUncompressedSize);
   Log.t("... size uncompressed: " + totalUncompressedSize);
   return super.doInBackgroundWithException(params);
 }
  @Override
  protected void onPostSuccess(File destinationFile) {
    super.onPostSuccess(destinationFile);
    Log.t("... finished unzipping file");
    StringBuilder log = new StringBuilder("... should delete source:" + deleteSourceOnSuccess);
    if (deleteSourceOnSuccess) {
      if (zipFile != null) {
        if (zipFile.exists()) {
          if (zipFile.delete()) {
            log.append(" - success");
          }
        } else {
          log.append(" - ").append(zipFile).append(" does not exist");
        }

      } else {
        log.append(" - zipfile null");
      }
    }
    Log.t(log);
  }