Hibernate 双向 1 对 1 对象关系映射 —外键关联 下 ，测试 crud

package com.baidu.one2one.foreign;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.hibernate.service.ServiceRegistry;import org.hibernate.service.ServiceRegistryBuilder;import org.junit.After;import org.junit.Before;import org.junit.Test;public class TestPC {private  SessionFactory sessionFactory;private  Session session;private  Transaction transaction;@Beforepublic void init(){Configuration configuration = new Configuration().configure();ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()  .applySettings(configuration.getProperties())  .buildServiceRegistry();sessionFactory = configuration.buildSessionFactory(serviceRegistry);session = sessionFactory.openSession();transaction = session.beginTransaction();System.out.println("init....");}@Afterpublic void destroy(){transaction.commit();session.close();sessionFactory.close();System.out.println("destory....");}@Testpublic void testGet2() {//在查询  没有外键  的实体对象时，使用左外连接查询，一并查询出其关联的对象//并已经进行初始化Person person = (Person) session.get(Person.class, 1);System.out.println(person.getPersonName());System.out.println(person.getCard().getCardName());}@Testpublic void testGet() {//1.默认情况下对关联属性使用懒加载Card card = (Card) session.get(Card.class, 1);System.out.println(card.getCardName());//2. 所以会出现懒加载异常的问题//session.close();//Person person = card.getPerson();//System.out.println(person.getClass());//System.out.println(person.getPersonName());/** * 3. 查询Person 对象的连接条件应该是person0_.PERSON_ID=card1_.PERS_ID  *       而不应该是 person0_.PERSON_ID=card1_.CARD_ID  * * 如何解决： *         在Person 即配置one-to-one 的一端添加属性：property-ref="person" *   <one-to-one name="card" class="Card" property-ref="person" ></one-to-one> */Person person = card.getPerson();System.out.println(person.getPersonName());}@Testpublic void testSave() {Person person = new Person();person.setPersonName("Person-3");person.setAge(25);Card card = new Card();card.setCardName("Operat Card");//设定关联关系card.setPerson(person);person.setCard(card);//save 操作//建议先保存没有外键列的那个对象，这样会减少UPDATE语句session.save(card);session.save(person);}}