@MapsId("userId")
@OneToOne
@JoinColumn(name = "user_id")
private User user;

@Entity
public class UserProfile {
    @Id
    private Long userId;

    @MapsId
    @OneToOne
    @JoinColumn(name = "user_id")
    private User user;

    // Остальные поля и методы
}

@Entity
public class Order {
    @Id
    private Long orderId;

    @MapsId("userId")
    @ManyToOne
    @JoinColumn(name = "user_id")
    private User user;

    // Остальные поля и методы
}

@Entity
public class UserProfile {
    @EmbeddedId
    private UserProfileId id;

    @MapsId("userId")
    @ManyToOne
    @JoinColumns({
        @JoinColumn(name = "department_id", referencedColumnName = "departmentId"),
        @JoinColumn(name = "user_id", referencedColumnName = "userId")
    })
    private User user;

    // Остальные поля и методы
}

public interface UserProfileRepository extends JpaRepository<UserProfile, Long> {
    // Методы репозитория
}

@Entity
@EntityListeners(AuditingEntityListener.class)
public class Document {
    @CreatedBy
    private String createdBy;

    // Другие поля
}

@Configuration
@EnableJpaAuditing
public class AuditConfig {
    @Bean
    public AuditorAware<String> auditorProvider() {
        return () -> Optional.ofNullable(SecurityContextHolder.getContext())
                            .map(SecurityContext::getAuthentication)
                            .map(Authentication::getName);
    }
}

@Entity
@EntityListeners(AuditingEntityListener.class)
public class Order {
    @CreatedBy
    private String createdBy;
    
    @CreatedDate
    private LocalDateTime createdDate;
    
    // Другие поля
}

spring.security.user.name=admin
spring.security.user.password=secret

public class SecurityAuditorAware implements AuditorAware<String> {
    @Override
    public Optional<String> getCurrentAuditor() {
        return Optional.ofNullable(SecurityContextHolder.getContext())
                      .map(SecurityContext::getAuthentication)
                      .filter(Authentication::isAuthenticated)
                      .map(Authentication::getName);
    }
}

@CreatedBy
private String createdBy;

@CreatedDate
private LocalDateTime createdDate;

@LastModifiedBy
private String lastModifiedBy;

@LastModifiedDate
private LocalDateTime lastModifiedDate;

import java.util.LinkedList;

public class Task310325 {
    public static void main(String[] args) {
        LinkedList<Integer> list = new LinkedList<>();
        list.add(1);
        list.add(2);
        list.addFirst(3);
        list.removeLast();
        
        System.out.println(list.get(1));
    }
}