Java高级框架应用开发案例教程（八）.ppt

8.2 一对一关系 4．DAO 在DAO类中，我们可以通过getter/setter来使用关系，完成联表操作： package com.ascent.dao; import org.hibernate.Session; import org.hibernate.Transaction; import com.ascent.po.Address; import com.ascent.po.Customer; import com.ascent.util.HibernateSessionFactory; public class CustomerAndAddressDAO { ? 8.2 一对一关系 /** * 案例模拟保存客户操作 级联插入相关联的Address * @param customer */ public void saveCustomer(Customer customer){ Session session = HibernateSessionFactory.getSession(); Transaction tx = null; try { tx = session.beginTransaction(); session.save(customer); mit(); }catch (Exception e) { if (tx != null) { tx.rollback(); } } finally { session.close(); } } 8.2 一对一关系 /** * 案例模拟根据id查询Customer方法 */ public Customer findCustomerById(int id){ Customer customer = null; Session session = HibernateSessionFactory.getSession(); customer =(Customer)session.get(Customer.class, id); session.close(); return customer; } 8.2 一对一关系 //模拟测试 public static void main(String[] args) { CustomerAndAddressDAO dao = new CustomerAndAddressDAO(); //创建一个Customer对象 Customer customer=new Customer(); //创建一个Address对象 Address address=new Address(); address.setProvince(province1); address.setCity(city1); address.setStreet(street1); address.setZipcode(100085); 8.2 一对一关系 //设置Address对象和Customer对象关系 address.setCustomer(customer); customer.setName(Peter); //设置Customer对象和Address对象关系 customer.setAddress(address); //测试保存Customer对象 dao.saveCustomer(customer); //测试根据id查询Customer方法 Customer c = dao.findCustomerById(customer.getId()); //打印Customer信息及一一对应的Address对象信息 System.out.println(Customer ID:+c.getId()); System.out.println(Customer Name:+c.getName()); System.out.println(Customer Addressid:+c.getAddress().getId()); System.out.println(Customer Addressstreet:+c.getAddress().getStreet());