Spring security makes a session when a user access the log in page - spring

Question

I'm making log in page, following official guide.
I want to add a function which makes redirect to home if a user join.
The logic is like this.
A user join with email, password and username.
Joinpage redirect to log in page.
if there is authentication, directly go to home.
How can I redirect to home with authentication?
#Slf4j
#Controller
#RequiredArgsConstructor
public class LoginController {
#GetMapping("/login")
public String loginForm(#ModelAttribute LoginForm loginForm) {
return "login/loginForm";
}
}
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
private final UserSecurityService userSecurityService;
#Override
protected void configure(HttpSecurity http) throws Exception {
http.authorizeRequests() // 인가 요청 받기
.antMatchers("/", "/home", "/join",
"/css/**", "/*.ico", "/error").permitAll()
.anyRequest().authenticated()
.and()
.formLogin()
.loginPage("/login")
.defaultSuccessUrl("/")
.failureUrl("/login")
.usernameParameter("email")
.permitAll()
.and()
.logout()
.logoutUrl("/logout")
.logoutSuccessUrl("/login")
.invalidateHttpSession(true);
}

Answer 1

basically, the security generates user session along the SessionCreationPolicy value when the user logins successfully.
if you want to change the session system to stateless system.
but following the below code.
protected void configure(HttpSecurity http) throws Exception {
http
.sessionManagement()
.sessionCreationPolicy(SessionCreationPolicy.STATELESS)
}
and then, you need to set the authentication object.
SecurityContextHolder.getContext().setAuthentication(
new UsernamePasswordAuthenticationToken("principal", "credentials", null));