Spring Boot Security Request method 'POST' not supported

Question

I am using spring boot security to handle login function. I don't know somehow the post method for login can't work at all. It will always throw the following exception.

There was an unexpected error (type=Method Not Allowed, status=405).
Request method 'POST' not supported

Can somebody suggest? Here is my code. You can find it from GitHub as well.

SecurityConfiguration

@Configuration
@EnableWebSecurity
public class SecurityConfiguration extends WebSecurityConfigurerAdapter {

    @Autowired
    private UserDetailsService userDetailsService;

    @Bean
    public BCryptPasswordEncoder bCryptPasswordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests().anyRequest().permitAll().and().csrf().disable();
    }

    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userDetailsService).passwordEncoder(bCryptPasswordEncoder());
    }
}

HomeController

@Controller
public class HomeController {
    @Autowired
    private UserService userService;

    @RequestMapping(value = { "/", "/login" }, method = RequestMethod.GET)
    public ModelAndView login(Model model) {
        ModelAndView modelAndView = new ModelAndView("auth/login");
        User user = new User();
        modelAndView.addObject(user);
        return modelAndView;
    }
}

login.html

<form class="form-horizontal" role="form" th:action="@{login}" method="post">
    <div class="form-group">
        <label class="col-md-4 control-label">Username</label>

        <div class="col-md-6">
            <input type="text" class="form-control" name="username" th:placeholder="Username"/>
        </div>
    </div>

    <div class="form-group">
        <label for="password" class="col-md-4 control-label">Password</label>

        <div class="col-md-6">
            <input type="password" class="form-control" name="password" th:placeholder="Password"/>
        </div>
    </div>


    <div class="form-group">
        <div class="col-md-6 col-md-offset-4">
            <button type="submit" class="btn btn-primary">
                <i class="fa fa-btn fa-sign-in"></i> Login
            </button>

        </div>
    </div>

    <div align="center" th:if="${param.error}">
        <p style="font-size: 20; color: #FF1C19;">Email or Password invalid, please verify</p>
    </div>
</form> 

Answer 1

Your Login function only accept GET requests. You should change GET to POST

@RestController
public class HomeController {
   @Autowired
   private UserService userService;

   @RequestMapping(value = { "/", "/login" }, method = RequestMethod.POST)
   public ModelAndView login(Model model) {
       ModelAndView modelAndView = new ModelAndView("auth/login");
       User user = new User();
       modelAndView.addObject(user);
       return modelAndView;
   }
}

Answer 2

You should change your Homecontroller login method like this:

@RequestMapping(value = { "/", "/login" }, method = RequestMethod.POST)
public ModelAndView login(Model model) {

or you could also use:

@PostMapping( value = { "/", "/login" })