使用spring登录vaadin后如何执行代码

Question

The user is setting the language and then login from a vaadin login view. I need the save the language the user set in a database.

I tryed using the addLoginListener function of the vaadin LoginForm. The problem with this is that it is triggered before the authentication finished. So someone could change the language of someone who he know the username of.

I also tryed Spring Authentication Events . The Problem with this is that i dont have access to the vaadin session wher I saved the language that should be written in the database.

Answer 1

You can find the VaadinSession you want in the authentication success handler using the current request:

public class CustomAuthenticationSuccessHandler extends SavedRequestAwareAuthenticationSuccessHandler {
​
    @Override
    public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response, Authentication authentication) throws ServletException, IOException {
        Optional<VaadinSession> maybeSession = VaadinSession.getAllSessions(
                request.getSession()).stream().findFirst();
​
        maybeSession.ifPresent(session -> {
            session.accessSynchronously(/* do something with session */);
        });
​
        super.onAuthenticationSuccess(request, response, authentication);
    }
​
}

This only works if you already have an existing VaadinSession ; if your login mechanism uses something else than a Vaadin UI (such as a SSO), then the session doesn't exist yet and things become a bit more complicated.