private Map _getParameters(String paramString) {
    Map navParams = new HashMap();

    if (paramString != null) {
      byte[] desMap = Base64.decode(paramString);

      Map naviState = null;

      try {
        naviState = ObjectDeserializer.deserializeMap(desMap);
      } catch (IOException iox) {
      } catch (ClassNotFoundException classNotFoundEx) {
      }

      if (naviState != null) {
        navParams.putAll(naviState);
      }
    }

    return navParams;
  }