code: public static boolean isZipFile(File zipFile) {
      try {
        ZipFile zf = new ZipFile(zipFile);
        boolean isZip = zf.getEntries().hasMoreElements();
        zf.close();
        return isZip;
      } catch (IOException e) {
        return false;
      }
    }
docs: <p>
  isZipFile.
  </p>
  
  @param zipFile a {@link java.io.File} object.
  @return a boolean.