How to log in by email instead of username in Spring security

I use Spring security. Is there a way to log in using email instead of a username in Spring security?

Answer

You need an “email” parameter in your login form

<input type="email" name="email">

Then let your custom WebSecurityConfigurerAdapter know that “email” is a principal parameter now

protected void configure(HttpSecurity http) throws Exception {
         http
            .formLogin()
            .loginPage("/login")
            .usernameParameter("email")
            .permitAll()
        .and()
            .logout()
            .permitAll();
}

Finally, override loadUserByUsername() in your UserDetailsService implementation

@Override
public UserDetails loadUserByUsername(String email) throws UsernameNotFoundException {
    User user = userRepo.findByEmail(email);

    if (user == null) {
        throw new UsernameNotFoundException("Not found!");
    }

    return user;
}