@Transactional(readOnly = true)
    public UserDetails loadUserByUsername(String email) throws UsernameNotFoundException {
                return new UserDTO(
                        userRepository.findByEmailAddress(email)
                                .orElseThrow(() -> new UsernameNotFoundException("User '" + email + "' not found."))
                );
    }

@Entity
@Table(name = "USERS")
@NoArgsConstructor
@AllArgsConstructor
@Getter
@Setter
@Builder
public class User extends BaseEntity {

    private String firstName;
    private String lastName;
    private String emailAddress;
    private String nickname;
    private String password;
    private boolean accountNonExpired;
    private boolean accountNonLocked;
    private boolean credentialsNonExpired;
    private boolean enabled;

    @ManyToMany
    @JoinTable(
            name = "USER_ROLE",
            joinColumns = @JoinColumn(name = "user_id", referencedColumnName = "id"),
            inverseJoinColumns = @JoinColumn(name = "role_id", referencedColumnName = "id"))
    private Set<Role> roles;

    public Set<Role> getRoles() {
        return roles;
    }
}

@Getter
@Setter
@NoArgsConstructor
public class UserDTO implements UserDetails {
    private Long id;
    private String firstName;
    private String lastName;
    private String username;
    private String nickname;
    private String password;
    private Set<RoleDTO> authorities;
    private boolean accountNonExpired;
    private boolean accountNonLocked;
    private boolean credentialsNonExpired;
    private boolean enabled;

    public UserDTO(User user){
        this.id = user.getId();
        this.firstName = user.getFirstName();
        this.lastName = user.getLastName();
        this.username = user.getEmailAddress();
        this.nickname = user.getNickname();
        this.password = user.getPassword();
        this.authorities = user.getRoles().stream().map(RoleDTO::new).collect(Collectors.toSet());
        this.accountNonExpired = user.isAccountNonExpired();
        this.accountNonLocked = user.isAccountNonLocked();
        this.credentialsNonExpired = user.isCredentialsNonExpired();
        this.enabled = user.isEnabled();
    }

}

INSERT INTO PUBLIC.ROLES(ID, VERSION, AUTHORITY) VALUES
(1, 0, 'ROLE_USER'),
(2, 0, 'ROLE_MODERATOR'),
(3, 0, 'ROLE_ADMIN');

@PostMapping
@ResponseStatus(HttpStatus.CREATED)
public UserSimpleDTO createUser(@RequestBody UserDTO user){
    return userService.createUser(user);
}

@GetMapping("/{id}")
@ResponseStatus(HttpStatus.OK)
public UserSimpleDTO getUserGeneralData(@PathVariable long id){
    return userService.getUserGeneralData(id);
}

@GetMapping("/{id}/details")
@ResponseStatus(HttpStatus.OK)
@RolesAllowed("ROLE_MODERATOR")
public UserDTO getUserDetailedInfo(@PathVariable long id) {
    return userService.getUserDetailedInfo(id);
}

@Entity
@Table(name = "ROLES")
@Getter
@NoArgsConstructor
public class Role extends BaseEntity implements GrantedAuthority {

    private String authority;

}

@Getter
    @NoArgsConstructor
    public class RoleDTO implements GrantedAuthority {

        private String authority;

        public RoleDTO(Role role){
           this.authority = role.getAuthority();
        }
    }