我必須從我的User班級(jí)中刪除一個(gè)登錄字段并email在 SecurityUtils 中用作用戶名我已經(jīng)j_username在前端更改了參數(shù)，但現(xiàn)在問題仍然存在于后端public static String getCurrentUserLogin() {        SecurityContext securityContext = SecurityContextHolder.getContext();        Authentication authentication = securityContext.getAuthentication();        String userName = null;        if (authentication != null) {            if (authentication.getPrincipal() instanceof UserDetails) {                UserDetails springSecurityUser = (UserDetails) authentication.getPrincipal();                userName = springSecurityUser.getUsername();            } else if (authentication.getPrincipal() instanceof String) {                userName = (String) authentication.getPrincipal();            }        }        return userName;    }結(jié)果userName是空的，因?yàn)閁serDetails并且Authentication沒有電子郵件。如何將字段設(shè)置email為“j_username”？我試過這個(gè)如何在春季安全中通過電子郵件而不是用戶名登錄解決方案，但這還不夠，因?yàn)槲沂褂昧薬nonymousUser另外，我有一個(gè)實(shí)現(xiàn)，UserDetailsService但是在調(diào)試時(shí)它不會(huì)被調(diào)用anonymousUserpublic class DomainUserDetailsService implements UserDetailsService {    private final UserRepository userRepository;    public DomainUserDetailsService(UserRepository userRepository) {        this.userRepository = userRepository;    }    @Override    public UserDetails loadUserByUsername(final String login) {        String lowercaseLogin = login.toLowerCase(Locale.ENGLISH);        Optional<User> userFromDatabase = userRepository.findOneByLogin(lowercaseLogin);        return userFromDatabase.map(user -> {            if (!user.getActivated()) {                throw new UserNotActivatedException("User " + lowercaseLogin + " was not activated");            }            List<GrantedAuthority> grantedAuthorities = user.getAuthorities().stream()                .map(authority -> new SimpleGrantedAuthority(authority.getName()))                .collect(Collectors.toList());            return new org.springframework.security.core.userdetails.User(lowercaseLogin,                user.getPassword(),                grantedAuthorities);    }}