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Hibernate_8_Person和IdCard实例_一对一关系：基于外键
1）建立Person类：
public class Person {
private Integer id;
private String name;
private IdCard IdCard;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public IdCard getIdCard() {
return IdCard;
}
public void setIdCard(IdCard card) {
this.IdCard = card;
}
@Override
public String toString() {
return "Person [id=" + id + ",name=" + name + "]";
}
}
2）建立IdCard类：
public class IdCard {
private Integer id;
private String number;
private Person person;
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;
}
@Override
public String toString() {
return "IdCard [id=" + id + ",number=" + number + "]";
}
}
3）建立持久化类：
public class perAndIdDao {
/**
* save方法
*/
@Test
public void testSave() {
Session session = SessionFactoryTools.getSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
// ===============================================
// 新建两个Person对象
Person person1 = new Person();
person1.setName("张三");
Person person2 = new Person();
person2.setName("李四");
// 新建两个IdCard对象
IdCard idCard1 = new IdCard();
idCard1.setNumber("37292501");
IdCard idCard2 = new IdCard();
idCard2.setNumber("37292502");
// 加入关联对象
person1.setIdCard(idCard1);
person2.setIdCard(idCard2);
idCard1.setPerson(person1);
idCard2.setPerson(person2);
// 保存
session.save(person1);
session.save(person2);
session.save(idCard1);
session.save(idCard2);
// ===============================================
tx.commit();
} catch (RuntimeException e) {
if (tx != null) {
tx.rollback();
}
throw e;
} finally {
session.close();
}
}
/**
* getById方法
*/
@Test
public void testGetById() {
Session session = SessionFactoryTools.getSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
// ===============================================
// 获取person队象并打印改队象的信息和相关联的idCard信息
Person person = (Person) session.get(Person.class, 1);
System.out.println(person + ":");
System.out.println(person.getIdCard());
// 获取idCard对象并打印改队象的信息和相关联的person信息
IdCard idCard = (IdCard) session.get(IdCard.class, 2);
System.out.println(idCard + ":");
System.out.println(idCard.getPerson());
// ===============================================
tx.commit();
} catch (RuntimeException e) {
if (tx != null) {
tx.rollback();
}
throw e;
} finally {
session.close();
}
}
/**
* 解除关联关系的方法
*/
@Test
public void testRemoveRelation() {
Session session = SessionFactoryTools.getSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
// ===============================================
/**
* 获取person对象并将其关联的IdCard设置为空 在多对一中，
* 因为一方不具有外键管理权。所以解除外键关联是不能实现的
* Person person = (Person) session.get(Person.class, 1);
* person.setIdCard(null);
*/
/**
* 获取idCard对象并将其相关联的person设置为空 在多对一中，
* 因为多方具有外键的管理权限，所以该外键的解除是能够实现的
*/
IdCard idCard = (IdCard) session.get(IdCard.class, 1);
idCard.setPerson(null);
// ===============================================
tx.commit();
} catch (RuntimeException e) {
if (tx != null) {
tx.rollback();
}
throw e;
} finally {
session.close();
}
}
/**
* 删除队象的方法
*/
@Test
public void testDelete() {
Session session = SessionFactoryTools.getSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
// ===============================================
/**
* 获取person对象并删除该对象
* 在多对一中。因为一方不具有外键的管理权限。
所以删除该对象是不可能实现的
* Person person = (Person) session.get(Person.class, 1);
* session.delete(person);
*/
/**
* 获取idCard对象并删除该对象
* 在多对一中。因为多方具有外键爱你的管理权限，
* 所以删除该对象是能够实现的
*/
IdCard idCard = (IdCard) session.get(IdCard.class, 1);
session.delete(idCard);
// ===============================================
tx.commit();
} catch (RuntimeException e) {
if (tx != null) {
tx.rollback();
}
throw e;
} finally {
session.close();
}
}
}
4）Person.hbm.xml的配置：
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="map_3"> <!--类名：Person 类相应的表名：person 一对一相应类：IdCard 一对一相应的表：idCard 一对一所相应的外键的属性名：person --> <class name="Person" table="person"> <id name="id" type="int" column="id"> <generator class="native" /> </id> <property name="name" type="string" column="name" length="20" /> <one-to-one name="idCard" class="IdCard" property-ref="person"> </one-to-one> </class> </hibernate-mapping>
5）IdCard.hbm.xml的配置：
<?xml version="1.0"?
> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="map_3"> <!--类名：IdCard 类相应的表名：idCard 多对一相应类的表名：person 多对一相应的类名：Person 多对一相应的列名：personId 设置为一对一关系：unique="true" --> <class name="IdCard" table="idCard"> <id name="id" type="int" column="id"> <generator class="native" /> </id> <property name="number" type="string" column="number" /> <many-to-one name="person" class="Person" column="personId" unique="true"> </many-to-one> </class> </hibernate-mapping>
6) 主文件的配置：
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory name="foo"> <!-- 配置数据库信息 --> <property name="hibernate.dialect"> org.hibernate.dialect.MySQLDialect </property> <property name="connection.url"> jdbc:mysql:///hibernate0 </property> <property name="connection.driver_class"> com.mysql.jdbc.Driver </property> <property name="connection.username">root</property> <property name="hibernate.connection.password">root</property> <!-- 其它配置 --> <property name="hibernate.show_sql">false</property> <property name="hibernate.format_sql">false</property> <property name="hbm2ddl.auto">update</property> <!-- 映射文件配置 --> <mapping resource="map_3/Person.hbm.xml" /> <mapping resource="map_3/IdCard.hbm.xml" /> </session-factory> </hibernate-configuration>
Hibernate_8_Person和IdCard实例_一对一关系：基于外键