Spring Securityの追加ログインフィールド

public class SimpleAuthenticationFilter
  extends UsernamePasswordAuthenticationFilter {

    @Override
    public Authentication attemptAuthentication(
      HttpServletRequest request,
      HttpServletResponse response)
        throws AuthenticationException {

       //...

        UsernamePasswordAuthenticationToken authRequest
          = getAuthRequest(request);
        setDetails(request, authRequest);

        return this.getAuthenticationManager()
          .authenticate(authRequest);
    }

    private UsernamePasswordAuthenticationToken getAuthRequest(
      HttpServletRequest request) {

        String username = obtainUsername(request);
        String password = obtainPassword(request);
        String domain = obtainDomain(request);

       //...

        String usernameDomain = String.format("%s%s%s", username.trim(),
          String.valueOf(Character.LINE__SEPARATOR), domain);
        return new UsernamePasswordAuthenticationToken(
          usernameDomain, password);
    }

   //other methods
}

public class SimpleUserDetailsService implements UserDetailsService {

   //...

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        String[]usernameAndDomain = StringUtils.split(
          username, String.valueOf(Character.LINE__SEPARATOR));
        if (usernameAndDomain == null || usernameAndDomain.length != 2) {
            throw new UsernameNotFoundException("Username and domain must be provided");
        }
        User user = userRepository.findUser(usernameAndDomain[0], usernameAndDomain[1]);
        if (user == null) {
            throw new UsernameNotFoundException(
              String.format("Username not found for domain, username=%s, domain=%s",
                usernameAndDomain[0], usernameAndDomain[1]));
        }
        return user;
    }
}

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

    http
      .addFilterBefore(authenticationFilter(),
        UsernamePasswordAuthenticationFilter.class)
      .authorizeRequests()
        .antMatchers("/css/** ** ", "/index").permitAll()
        .antMatchers("/user/** ** ").authenticated()
      .and()
      .formLogin().loginPage("/login")
      .and()
      .logout()
      .logoutUrl("/logout");
}

public AuthenticationProvider authProvider() {
    DaoAuthenticationProvider provider = new DaoAuthenticationProvider();
    provider.setUserDetailsService(userDetailsService);
    provider.setPasswordEncoder(passwordEncoder());
    return provider;
}

public SimpleAuthenticationFilter authenticationFilter() throws Exception {
    SimpleAuthenticationFilter filter = new SimpleAuthenticationFilter();
    filter.setAuthenticationManager(authenticationManagerBean());
    filter.setAuthenticationFailureHandler(failureHandler());
    return filter;
}

<form class="form-signin" th:action="@{/login}" method="post">
 <h2 class="form-signin-heading">Please sign in</h2>
 <p>Example: user/domain/password</p>
 <p th:if="${param.error}" class="error">Invalid user, password, or domain</p>
 <p>
   <label for="username" class="sr-only">Username</label>
   <input type="text" id="username" name="username" class="form-control"
     placeholder="Username" required autofocus/>
 </p>
 <p>
   <label for="domain" class="sr-only">Domain</label>
   <input type="text" id="domain" name="domain" class="form-control"
     placeholder="Domain" required autofocus/>
 </p>
 <p>
   <label for="password" class="sr-only">Password</label>
   <input type="password" id="password" name="password" class="form-control"
     placeholder="Password" required autofocus/>
 </p>
 <button class="btn btn-lg btn-primary btn-block" type="submit">Sign in</button><br/>
 <p><a href="/index" th:href="@{/index}">Back to home page</a></p>
</form>

public class CustomAuthenticationFilter
  extends UsernamePasswordAuthenticationFilter {

    public static final String SPRING__SECURITY__FORM__DOMAIN__KEY = "domain";

    @Override
    public Authentication attemptAuthentication(
        HttpServletRequest request,
        HttpServletResponse response)
          throws AuthenticationException {

       //...

        CustomAuthenticationToken authRequest = getAuthRequest(request);
        setDetails(request, authRequest);
        return this.getAuthenticationManager().authenticate(authRequest);
    }

    private CustomAuthenticationToken getAuthRequest(HttpServletRequest request) {
        String username = obtainUsername(request);
        String password = obtainPassword(request);
        String domain = obtainDomain(request);

       //...

        return new CustomAuthenticationToken(username, password, domain);
    }

 public UserDetails loadUserByUsernameAndDomain(String username, String domain)
     throws UsernameNotFoundException {
     if (StringUtils.isAnyBlank(username, domain)) {
         throw new UsernameNotFoundException("Username and domain must be provided");
     }
     User user = userRepository.findUser(username, domain);
     if (user == null) {
         throw new UsernameNotFoundException(
           String.format("Username not found for domain, username=%s, domain=%s",
             username, domain));
     }
     return user;
 }

@Override
protected UserDetails retrieveUser(String username,
  UsernamePasswordAuthenticationToken authentication)
    throws AuthenticationException {

    CustomAuthenticationToken auth = (CustomAuthenticationToken) authentication;
    UserDetails loadedUser;

    try {
        loadedUser = this.userDetailsService
          .loadUserByUsernameAndDomain(auth.getPrincipal()
            .toString(), auth.getDomain());
    } catch (UsernameNotFoundException notFound) {

        if (authentication.getCredentials() != null) {
            String presentedPassword = authentication.getCredentials()
              .toString();
            passwordEncoder.matches(presentedPassword, userNotFoundEncodedPassword);
        }
        throw notFound;
    } catch (Exception repositoryProblem) {

        throw new InternalAuthenticationServiceException(
          repositoryProblem.getMessage(), repositoryProblem);
    }

   //...

    return loadedUser;
}