I can't find out who is logged in.As #AuthenticationPrincipal is always null - spring

Question

Controller:
#PostMapping("/advertisement")
public void addProduct(#RequestBody Product product, #AuthenticationPrincipal CurrentUser user) {
System.out.println("Current user: " + user.getUsername());
productService.addProduct(product, user);}
I want to send data of the current user but it is not working. For example getUsername shows me null too.
Maybe my using of AuthenticationPrincipal is wrong.
This is Current user
public class CurrentUser implements UserDetails {
private Long id;
private String username;
private String password;
private List<GrantedAuthority> authorities;
public void setId(Long id) {
this.id = id;
}
public void setUsername(String username) {
this.username = username;
}
public void setPassword(String password) {
this.password = password;
}
public void setAuthority(String authority) {
this.authorities = List.of(new SimpleGrantedAuthority(authority));
}
#Override
public Collection<? extends GrantedAuthority> getAuthorities() {
return authorities;
}
public Long getId() {
return id;
}
#Override
public String getPassword() {
return password;
}
#Override
public String getUsername() {
return username;
}
#Override
public boolean isAccountNonExpired() {
return true;
}
#Override
public boolean isAccountNonLocked() {
return true;
}
#Override
public boolean isCredentialsNonExpired() {
return true;
}
#Override
public boolean isEnabled() {
return true;
}}
Current user service:
#Service
public class CurrentUserService implements UserDetailsService {
private final UserRepository repository;
#Autowired
public CurrentUserService(UserRepository repository) {
this.repository = repository;
}
#Override
public CurrentUser loadUserByUsername(String username) throws UsernameNotFoundException {
final UserEntity user = repository.findByUsername(username);
if (user != null) {
final CurrentUser currentUser = new CurrentUser();
currentUser.setId(user.getId());
currentUser.setUsername(user.getUsername());
currentUser.setPassword(user.getPassword());
currentUser.setAuthority(user.getAuthority());
System.out.println("Current user: " + currentUser.getUsername());
//bad attempts
Authentication auth = SecurityContextHolder.getContext().getAuthentication();
String name = auth.getName(); //get logged in username
//get principal
Object principal = SecurityContextHolder.getContext().getAuthentication().getPrincipal();
System.out.println("Principal: " + principal);
System.out.println(principal.toString());
return currentUser;
}
else {
throw new UsernameNotFoundException("Failed to find user with username: " + username);
}}
Security configuration
#Configuration
#EnableWebSecurity
public class AppConfig extends WebSecurityConfigurerAdapter {
#Autowired
private CurrentUserService currentUserService;
#Autowired
private SessionFilter sessionFilter;
#Autowired
private PasswordEncoder passwordEncoder;
#Override
protected void configure(AuthenticationManagerBuilder auth) throws Exception {
auth.userDetailsService(currentUserService).passwordEncoder(passwordEncoder);
}
#Override
protected void configure(HttpSecurity http) throws Exception {
http = http.cors().and().csrf().disable();
http = http.exceptionHandling().authenticationEntryPoint(
(request, response, ex) -> response.sendError(
HttpServletResponse.SC_UNAUTHORIZED,
ex.getMessage())
).and();
http.authorizeRequests()
.antMatchers(HttpMethod.GET, "/api/**").permitAll()
.antMatchers(HttpMethod.POST, "/api/**").permitAll()
.antMatchers(HttpMethod.PUT, "/api/**").permitAll()
.antMatchers(HttpMethod.OPTIONS, "/api/**").permitAll()
.antMatchers(HttpMethod.GET, "/**").permitAll()
.antMatchers(HttpMethod.POST, "/**").permitAll()
.antMatchers(HttpMethod.PUT, "/**").permitAll()
.antMatchers(HttpMethod.OPTIONS, "/**").permitAll()
.antMatchers("/api/**").authenticated()
.antMatchers(HttpMethod.GET, "/**").permitAll()
.antMatchers(HttpMethod.POST, "/**").permitAll()
.anyRequest().authenticated();
http.addFilterBefore(
sessionFilter,
UsernamePasswordAuthenticationFilter.class
);
}
#Override
#Bean
public AuthenticationManager authenticationManagerBean() throws Exception {
return super.authenticationManagerBean();
}
#Bean
public WebMvcConfigurer corsConfigurer() {
return new WebMvcConfigurer() {
#Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/**")
.allowedOrigins("http://localhost:4200")
.allowedMethods("*")
.allowCredentials(true);
}
};
}
#Bean
public BCryptPasswordEncoder passwordEncoder() {
return new BCryptPasswordEncoder();
}}
This is the first important step to be able to find out who is logged in.
Then I'll want to put it in a one to one relationship with product. This is reason why I need to find out who is logged in.
I hope someone smarter than me,Can help and advise me :).Thanks for every response.