Spring-boot读书笔记一LoginController

The LoginController is invoked in several ways:

1. Direct URL Access
When users navigate to /login in their browser, Spring's DispatcherServlet routes the request to the LoginController.login() method.

2. Spring Security Redirect

• From your SecurityConfiguration.java: .formLogin().loginPage("/login")
• Spring Security automatically redirects unauthenticated users to /login when they try to access protected resources.

3. Automatic Spring Boot Registration

• The @Controller annotation makes Spring automatically discover and register this controller
• Spring Boot's auto-configuration scans for @Controller classes in the package hierarchy
• The @GetMapping("/login") maps HTTP GET requests to /login URL to the login() method

Flow:

• User tries to access a protected page (like /courses)
• Spring Security intercepts the request
• Since user is not authenticated, Security redirects to /login
• LoginController.login() method is invoked
• Returns "login" view name, which renders the login page template

The controller is essentially the bridge between the security configuration and the login page view.