Spring Boot with Spring Security formlogin in memory auth Whitelabel Status 404

Question

I'm getting the following error after logging in using the default formlogin(). I'm confused about what I am doing wrong because I keep getting this page when I do it without the in-memory users. I'm using packages too. I'm a bit lost here.

Whitelabel Error Page This application has no explicit mapping for /error, so you are seeing this as a fallback. There was an unexpected error (type=Not Found, status=404).

This is a Spring Boot w/ Spring Security using the default formlogin() with basic in-memory authentication for two roles: user and admin

I have three packages: main, config, controller

Package com.demo

 @SpringBootApplication
  public class InMemoryAuthenticationApplication {

  public static void main(String[] args) {
    SpringApplication.run(InMemoryAuthenticationApplication.class, args);
    }   

Package com.demo.configuration

 @Configuration
 @EnableWebSecurity
 public class SpringSecurityConfig extends WebSecurityConfigurerAdapter {

@Override
protected void configure(final AuthenticationManagerBuilder auth) throws    Exception {
        auth.inMemoryAuthentication()
            .withUser("springuser").password(passwordEncoder().encode("spring123")).roles("USER")
            .and()
            .withUser("springadmin").password(passwordEncoder().encode("admin123"))
            .roles("ADMIN", "USER");

    }


@Override
protected void configure(HttpSecurity http) throws Exception {

    http
    .authorizeRequests()
    .antMatchers("/admin*").hasRole("ADMIN")
    .antMatchers("/user*").hasRole("USER")
    .anyRequest().authenticated()
    .and()
    .formLogin();

    }
@Bean
public PasswordEncoder passwordEncoder() {
    return new BCryptPasswordEncoder();
    }
}

Package com.demo.controller

@RestController
public class LoginController {

@GetMapping("/admin")
public String userhome () {
    return "admin";
}
@GetMapping("/user")
public String adminhome () {
    return "user";
   }

}  

Answer 1

Can you try updating your controller annotation from @RestController to @Controller .

Reason being i can see your controller methods have return type string ie probably an HTML page.