/**
   * Logout a Trade User Dispatch to the Trade Welcome JSP for display
   *
   * @param userID The User to logout
   * @param ctx the servlet context
   * @param req the HttpRequest object
   * @param resp the HttpResponse object
   * @param results A short description of the results/success of this web request provided on the
   *     web page
   * @exception javax.servlet.ServletException If a servlet specific exception is encountered
   * @exception javax.io.IOException If an exception occurs while writing results back to the user
   */
  void doLogout(ServletContext ctx, HttpServletRequest req, HttpServletResponse resp, String userID)
      throws ServletException, IOException {
    String results = "";

    try {
      tAction.logout(userID);

    } catch (java.lang.IllegalArgumentException e) { // this is a user error so I will
      // forward them to another page, at the end of the page.
      req.setAttribute("results", results + "illegal argument:" + e.getMessage());

      // log the exception with an error level of 3 which means, handled exception but would
      // invalidate a automation run
      Log.error(
          e,
          "TradeServletAction.doLogout(...)",
          "illegal argument, information should be in exception string",
          "treating this as a user error and forwarding on to a new page");
    } catch (Exception e) {
      // log the exception and foward to a error page
      Log.error(
          e,
          "TradeServletAction.doLogout(...):",
          "Error logging out" + userID,
          "fowarding to an error page");
      // set the status_code to 500
      throw new ServletException(
          "TradeServletAction.doLogout(...)" + "exception logging out user " + userID, e);
    }
    HttpSession session = req.getSession();
    if (session != null) {
      session.invalidate();
    }

    Object o = req.getAttribute("TSS-RecreateSessionInLogout");
    if (o != null && ((Boolean) o).equals(Boolean.TRUE)) {
      // Recreate Session object before writing output to the response
      // Once the response headers are written back to the client the opportunity
      // to create a new session in this request may be lost
      // This is to handle only the TradeScenarioServlet case
      session = req.getSession(true);
    }
    requestDispatch(ctx, req, resp, userID, TradeConfig.getPage(TradeConfig.WELCOME_PAGE));
  }