如何使用Hibernate / JPA将Oracle类型的对象转换为Java对象？

// 实体类
@Entity
@Table(name = "employee")
public class Employee {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private Integer age;
    // 其他属性和方法
}

// DAO接口
public interface EmployeeDAO {
    Employee findById(Long id);
    void save(Employee employee);
    void update(Employee employee);
    void delete(Employee employee);
}

// DAO实现类
@Repository
public class EmployeeDAOImpl implements EmployeeDAO {
    @PersistenceContext
    private EntityManager entityManager;

    @Override
    public Employee findById(Long id) {
        return entityManager.find(Employee.class, id);
    }

    @Override
    public void save(Employee employee) {
        entityManager.persist(employee);
    }

    @Override
    public void update(Employee employee) {
        entityManager.merge(employee);
    }

    @Override
    public void delete(Employee employee) {
        entityManager.remove(employee);
    }
}

// 使用示例
public class Main {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        EmployeeDAO employeeDAO = context.getBean(EmployeeDAO.class);

        // 查询
        Employee employee = employeeDAO.findById(1L);
        System.out.println(employee.getName());

        // 新增
        Employee newEmployee = new Employee();
        newEmployee.setName("John");
        newEmployee.setAge(30);
        employeeDAO.save(newEmployee);

        // 更新
        employee.setAge(40);
        employeeDAO.update(employee);

        // 删除
        employeeDAO.delete(employee);
    }
}