Add flash attribute to logout in Spring Security

Question

I am using Spring Security, and I would like to add a flash attribute to the automatic redirect to the login page. However, the handle method of the LogoutSuccessHandler only has HttpServletRequest, HttpServletResponse, Authentication as parameters. How can I retrieve the RedirectAttributes within the handle method in order to add flash attributes? Or is there an other way to add to flash attributes to the logout redirect?

Answer 1

For me, the following code worked:

public class CustomLogoutSuccessHandler extends SimpleUrlLogoutSuccessHandler {
    @Override
    public void onLogoutSuccess(HttpServletRequest request, HttpServletResponse response, Authentication authentication)
            throws IOException, ServletException {
        final FlashMap flashMap = new FlashMap();
        flashMap.put("information", "You've been logged out.");
        final FlashMapManager flashMapManager = new SessionFlashMapManager();
        flashMapManager.saveOutputFlashMap(flashMap, request, response);
        response.sendRedirect("/"); // or any other location you want
        super.handle(request, response, authentication);
    }
}

Inspiration was taken from this answer by user @vallismortis.