LogoutHandler not called after changing the configuration to lambdas

In my SpringBoot-App, I am using an implementation of a Logout-handler to put together a redirect-uri. Since the method logout() (without parameters) of HttpSecurity has been deprecated, I am attempting to configure the logout with lambdas. In my eyes, it should do the same, the behaviour however turns out to be different.

The logout handler looks like this:

public class MyCustomLogoutHandler implements LogoutHandler{

    @Override
    public void logout(HttpServletRequest request, HttpServletResponse response,
        Authentication authentication) {
        try {
            response.sendRedirect(assembleUri());
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

}

Old (and working) config:

httpSecurity.logout()
    .logoutUrl("/sso/logout")
    .permitAll()
    .addLogoutHandler(new MyCustomLogoutHandler());

I changed it into the following:

httpSecurity.logout(config -> config.logoutUrl("sso/logout")
    .permitAll()
    .addLogoutHandler(new MyCustomLogoutHandler()));

But now, the method "logout" is not called anymore and i end up in a 404.

What could be the mistake here?

>Solution :

Missing "/" in Logout URL:

In the lambda configuration, you’ve used .logoutUrl("sso/logout"). Make sure that the URL should begin with a "/" to be treated as an absolute URL path. So, it should be .logoutUrl("/sso/logout").

httpSecurity.logout(config -> config.logoutUrl("/sso/logout")
    .permitAll()
    .addLogoutHandler(new MyCustomLogoutHandler()));