package h_hbm_oneToOne2;public class Person {private Integer id;private String name;private IdCard idCard;//关联的身份证public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public IdCard getIdCard() {return idCard;}public void setIdCard(IdCard idCard) {this.idCard = idCard;}}

package h_hbm_oneToOne2;public class IdCard {private Integer id;private String number;private Person person;//不要初始化，初始化会使对象处于临时状态，会使保存的时候抛异常，关联的人的对象public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getNumber() {return number;}public void setNumber(String number) {this.number = number;}public Person getPerson() {return person;}public void setPerson(Person person) {this.person = person;}}

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<!-- This mapping demonstrates -->
<!-- 告诉hibernate需要找哪个表 -->
<hibernate-mapping package="h_hbm_oneToOne2"><!-- User表对应的映射关系 --><class name="IdCard" table="idCard"><id name="id"><generator class="native" /></id><property column="number" name="number" type="string" /><!-- person属性：Person类型表达的是本类与IdCard的一对一关系采用基于主键的一对一映射的方式本方无外键方property-ref：写的是对方映射中外键列对应的属性名，也就是Person类下的idCard属性名--><one-to-one name="person" class="Person"/></class>
</hibernate-mapping>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<!-- This mapping demonstrates -->
<!-- 告诉hibernate需要找哪个表 -->
<hibernate-mapping package="h_hbm_oneToOne2"><!-- User表对应的映射关系 --><class name="Person" table="person"><id name="id"><!-- 当使用基于主键的一对一映射时，有外键方的主键生成策略一定要是foreign 参数property：生成主键值时所根据的对象【一对一时关联的对方】--><generator class="foreign"><param name="property">idCard</param></generator></id><property column="name" name="name" type="string" /><!-- IdCard属性：IdCard类型表达的是本类与IdCard的一对一关系采用基于主键的一对一映射的方式本方有外键--><one-to-one name="idCard" class="IdCard" constrained="true"></one-to-one></class>
</hibernate-mapping>

package h_hbm_oneToOne2;import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.Test;import cn.marer.model.HibernateUtils;public class APP {private static SessionFactory sessionfactory = HibernateUtils.getSessionFactory();@Testpublic void testSave(){Session session = sessionfactory.openSession();//开启事务session.beginTransaction();//构建对象Person person = new Person();person.setName("张三");IdCard id = new IdCard();id.setNumber("123456");person.setIdCard(id);//     session.save(id);session.save(person);//提交事务session.getTransaction().commit();session.close();}@Testpublic void testGet(){Session session = sessionfactory.openSession();//开启事务session.beginTransaction();//获取一方
//      Person person= (Person) session.get(Person.class, 1);
//      System.out.println(person.getName()+"---->" + person.getIdCard());IdCard id = (IdCard) session.get(IdCard.class, 1);System.out.println(id.getNumber() + "---->" + id.getPerson().getName());//提交事务session.getTransaction().commit();session.close();}// 解除关联关系@Testpublic void testRemoveRelation(){Session session = sessionfactory.openSession();// 开启事务session.beginTransaction();// 从无外键方解除关联关系不可以IdCard id = (IdCard) session.get(IdCard.class, 1);id.setPerson(null);// 基于主键的一对一映射，从有外键方解除关联关系，不可以。因为主键不能为空。
//      Person person = (Person) session.get(Person.class, 1);
//      person.setIdCard(null);//提交事务session.getTransaction().commit();session.close();}// 删除对对方的影响@Testpublic void testDelte(){Session session = sessionfactory.openSession();// 开启事务session.beginTransaction();// 会报异常
//      IdCard id = (IdCard) session.get(IdCard.class, 1);
//      session.delete(id);// 如果没有关联的对方，能删除// 如果有关联的对方：因为会直接执行删除自己，所以无外键方会有异常，有外键方没有异常。Person person = (Person) session.get(Person.class, 1);session.delete(person);// 有外键方能维护关联关系，从无外键方不能维护关联关系//提交事务session.getTransaction().commit();session.close();}
}