JPA -从OneToMany关系中获取给定条件的数据

@Entity
public class Order {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    // 其他属性...

    @OneToMany(mappedBy = "order")
    private List<OrderItem> orderItems;
    
    // getter和setter方法...
}

@Entity
public class OrderItem {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    // 其他属性...

    @ManyToOne
    @JoinColumn(name = "order_id")
    private Order order;
    
    // getter和setter方法...
}

public List<OrderItem> getOrderItemsByOrderId(Long orderId) {
    EntityManager entityManager = ...; // 创建EntityManager对象，可以使用JPA的EntityManagerFactory来获取
    CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
    CriteriaQuery<OrderItem> query = criteriaBuilder.createQuery(OrderItem.class);
    Root<OrderItem> root = query.from(OrderItem.class);
    query.select(root)
         .where(criteriaBuilder.equal(root.get("order").get("id"), orderId));

    TypedQuery<OrderItem> typedQuery = entityManager.createQuery(query);
    return typedQuery.getResultList();
}