如何从已登录的用户那里获取 email

Question

I have this problem. Trying to get email of already register user who is logged in my application. The idea is when i click "Profile", to see the email of logged user (and actually to see only the adds that the logged user have add in profile section). So my question is how can I connect html page with database and with current logged user? I have tried different ways, one of, but I get null for email, I have no idea why...

I use POSTGRESQL

This is my Entity

@Entity
@Table(name =  "username", uniqueConstraints = @UniqueConstraint(columnNames = "email"))
public class Username {

@Id
@GeneratedValue(strategy =  GenerationType.IDENTITY)
private Long id;

@Column(name = "first_name")
private String firstName;

@Column(name = "last_name")
private String lastName;

private String email;

private String password;

@ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
@JoinTable(
        name = "usernames_roles",
        joinColumns = @JoinColumn(
                name = "usernames_id", referencedColumnName = "id"),
        inverseJoinColumns = @JoinColumn(
                        name = "role_id", referencedColumnName = "id"))

private Collection<Role> roles;

public Username() {
    
}

This is security configuration

@Configuration
@EnableWebSecurity
public class SecurityConfiguration  extends WebSecurityConfigurerAdapter{

@Autowired
private UserService userService;

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

@Bean
public DaoAuthenticationProvider authenticationProvider() {
    DaoAuthenticationProvider auth = new DaoAuthenticationProvider();
    auth.setUserDetailsService(userService);
    auth.setPasswordEncoder(passwordEncoder());
    return auth;
}

@Override
protected void configure(AuthenticationManagerBuilder auth) throws Exception {
    auth.authenticationProvider(authenticationProvider());
}


//.antMatchers("/", "/home**").anonymous()
@Override
protected void configure(HttpSecurity http) throws Exception {
    http.authorizeRequests()
    
    
    .antMatchers("/", "/home","/cars","/motors**").anonymous()
    .antMatchers("/", "/home","/cars","/motors**").permitAll()
    .antMatchers("/cars/add").authenticated()
    .and()
    .formLogin()
    .loginPage("/login")
        .permitAll()
        .defaultSuccessUrl("/")
        .and()
    .logout()
    .invalidateHttpSession(true)
    .clearAuthentication(true)
    .logoutRequestMatcher(new AntPathRequestMatcher("/logout"))
    .logoutSuccessUrl("/login?logout")
    .permitAll();
}

Answer 1

First, you need setters and getters in your Username entity.

Then, you get the current user's login by:

String login = "";
if (SecurityContextHolder.getContext().getAuthentication() != null)
login = SecurityContextHolder.getContext().getAuthentication().getName();

Then you get the user by login, depending on what you've implemented in terms of querying your database (eg. Repository, Service, etc).

When you have your current userr, you just call its getEmail() .