Hibernate4之映射继承(十)
程序员文章站
2022-04-14 11:21:55
...
映射继承
- 每个具体类对应一个表
- 根类对应一个表
- 每个类对应一个表
一、每个具体类对应一个表
1.编写HibernateUtil类,用来获取sqlSession。
package com.newbeedaly.util;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
public class HibernateUtil {
private static final SessionFactory sessionFactory=buildSessionFactory();
private static SessionFactory buildSessionFactory(){
Configuration configuration=new Configuration().configure(); // 实例化配置文件
ServiceRegistry serviceRegistry=new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build(); // 实例化服务登记
return configuration.buildSessionFactory(serviceRegistry); // 获取Session工厂
}
public static SessionFactory getSessionFactory(){
return sessionFactory;
}
}
2.编写hibernate.cfg.xml配置文件
<?xml version='1.0' encoding='utf-8'?>
<!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>
<!--数据库连接设置 -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property>
<property name="connection.username">root</property>
<property name="connection.password">123456</property>
<!-- 方言 -->
<property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
<!-- 控制台显示SQL -->
<property name="show_sql">true</property>
<!-- 自动更新表结构 -->
<property name="hbm2ddl.auto">update</property>
<mapping resource="com/newbeedaly/model/Student.hbm.xml"/>
<mapping resource="com/newbeedaly/model/LifeImage.hbm.xml"/>
<mapping resource="com/newbeedaly/model/WorkImage.hbm.xml"/>
<mapping resource="com/newbeedaly/model/Student2.hbm.xml"/>
<mapping resource="com/newbeedaly/model/Image2.hbm.xml"/>
<mapping resource="com/newbeedaly/model/Student3.hbm.xml"/>
<mapping resource="com/newbeedaly/model/Image3.hbm.xml"/>
</session-factory>
</hibernate-configuration>
3.编写Student类,Image抽象类,WorkImage类,LifeImage类。
package com.newbeedaly.model;
import java.util.Set;
public class Student {
private int id;
private String name;
private Set<Image> images;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Set<Image> getImages() {
return images;
}
public void setImages(Set<Image> images) {
this.images = images;
}
}
package com.newbeedaly.model;
public abstract class Image {
private int id;
private String imageName;
private Student student;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getImageName() {
return imageName;
}
public void setImageName(String imageName) {
this.imageName = imageName;
}
public Student getStudent() {
return student;
}
public void setStudent(Student student) {
this.student = student;
}
}
package com.newbeedaly.model;
public class WorkImage extends Image{
}
package com.newbeedaly.model;
public class LifeImage extends Image{
}
4.编写Student.hbm.xml,LifeImage.hbm.xml,WorkImage.hbm.xml配置文件
<?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">
<hibernate-mapping package="com.newbeedaly.model">
<class name="Student" table="t_student">
<id name="id" column="stuId">
<generator class="native"></generator>
</id>
<property name="name" column="stuName"></property>
</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">
<hibernate-mapping package="com.newbeedaly.model">
<class name="LifeImage" table="t_lifeImage">
<id name="id" column="lifeImageId">
<generator class="native"></generator>
</id>
<property name="imageName" column="imageName"></property>
<many-to-one name="student" column="stuId" class="com.newbeedaly.model.Student"></many-to-one>
</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">
<hibernate-mapping package="com.newbeedaly.model">
<class name="WorkImage" table="t_workImage">
<id name="id" column="workImageId">
<generator class="native"></generator>
</id>
<property name="imageName" column="imageName"></property>
<many-to-one name="student" column="stuId" class="com.newbeedaly.model.Student"></many-to-one>
</class>
</hibernate-mapping>
5.创建StudentTest类
package com.newbeedaly.service;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.newbeedaly.model.Image;
import com.newbeedaly.model.Image2;
import com.newbeedaly.model.Image3;
import com.newbeedaly.model.Student2;
import com.newbeedaly.model.Student3;
import com.newbeedaly.util.HibernateUtil;
public class StudentTest {
private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session;
@Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
}
@After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
}
@Test
public void testGetAllImages(){
List<Image> imageList=new ArrayList<Image>();
int stuId=1;
List<Image> lifeImageList=(List<Image>)session.createQuery("from LifeImage l where l.student.id="+stuId).list();
imageList.addAll(lifeImageList);
List<Image> workImageList=(List<Image>)session.createQuery("from WorkImage w where w.student.id="+stuId).list();
imageList.addAll(workImageList);
Iterator it=imageList.iterator();
while(it.hasNext()){
Image image=(Image)it.next();
System.out.println(image.getImageName());
}
}
@Test
public void testGetAllImages2(){
Student2 student2=(Student2)session.get(Student2.class, 1);
Set<Image2> images=student2.getImages();
Iterator it=images.iterator();
while(it.hasNext()){
Image2 image=(Image2)it.next();
System.out.println(image.getImageName());
}
}
@Test
public void testGetAllImages3(){
Student3 student3=(Student3)session.get(Student3.class, 1);
Set<Image3> images=student3.getImages();
Iterator it=images.iterator();
while(it.hasNext()){
Image3 image=(Image3)it.next();
System.out.println(image.getImageName());
}
}
}
二、根类对应一个表
1.编写Student2类,Image2类,WorkImage2类,LifeImage2类。
package com.newbeedaly.model;
import java.util.Set;
public class Student2 {
private int id;
private String name;
private Set<Image2> images;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Set<Image2> getImages() {
return images;
}
public void setImages(Set<Image2> images) {
this.images = images;
}
}
package com.newbeedaly.model;
public class Image2 {
private int id;
private String imageName;
private String imageType;
private Student2 student;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getImageName() {
return imageName;
}
public void setImageName(String imageName) {
this.imageName = imageName;
}
public Student2 getStudent() {
return student;
}
public void setStudent(Student2 student) {
this.student = student;
}
public String getImageType() {
return imageType;
}
public void setImageType(String imageType) {
this.imageType = imageType;
}
}
package com.newbeedaly.model;
public class WorkImage2 extends Image2{
}
package com.newbeedaly.model;
public class LifeImage2 extends Image2{
}
2.编写Student2.hbm.xml,Image2.hbm.xml
<?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">
<hibernate-mapping package="com.newbeedaly.model">
<class name="Student2" table="t_student2">
<id name="id" column="stuId">
<generator class="native"></generator>
</id>
<property name="name" column="stuName"></property>
<set name="images">
<key column="stuId"></key>
<one-to-many class="com.newbeedaly.model.Image2"/>
</set>
</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">
<hibernate-mapping package="com.newbeedaly.model">
<class name="Image2" table="t_image2">
<id name="id" column="imageId">
<generator class="native"></generator>
</id>
<discriminator column="imageType" type="string"></discriminator>
<property name="imageName" column="imageName"></property>
<many-to-one name="student" column="stuId" class="com.newbeedaly.model.Student2"></many-to-one>
<subclass name="com.newbeedaly.model.LifeImage2" discriminator-value="li"></subclass>
<subclass name="com.newbeedaly.model.WorkImage2" discriminator-value="wi"></subclass>
</class>
</hibernate-mapping>
3.运行StudentTest测试方法
三、每个类对应一个表
1.编写Student3类,Image3类,WorkImages3类,LifeImage3类。
package com.newbeedaly.model;
import java.util.Set;
public class Student3 {
private int id;
private String name;
private Set<Image3> images;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Set<Image3> getImages() {
return images;
}
public void setImages(Set<Image3> images) {
this.images = images;
}
}
package com.newbeedaly.model;
public class Image3 {
private int id;
private String imageName;
private Student3 student;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getImageName() {
return imageName;
}
public void setImageName(String imageName) {
this.imageName = imageName;
}
public Student3 getStudent() {
return student;
}
public void setStudent(Student3 student) {
this.student = student;
}
}
package com.newbeedaly.model;
public class WorkImage3 extends Image3{
}
package com.newbeedaly.model;
public class LifeImage3 extends Image3{
}
2.编写配置文件Student3.hbm.xml和Image3.bhm.xml
<?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">
<hibernate-mapping package="com.newbeedaly.model">
<class name="Student3" table="t_student3">
<id name="id" column="stuId">
<generator class="native"></generator>
</id>
<property name="name" column="stuName"></property>
<set name="images">
<key column="stuId"></key>
<one-to-many class="com.newbeedaly.model.Image3"/>
</set>
</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">
<hibernate-mapping package="com.newbeedaly.model">
<class name="Image3" table="t_image3">
<id name="id" column="imageId">
<generator class="native"></generator>
</id>
<property name="imageName" column="imageName"></property>
<many-to-one name="student" column="stuId" class="com.newbeedaly.model.Student3"></many-to-one>
<joined-subclass name="com.newbeedaly.model.LifeImage3" table="t_lifeImage3">
<key column="lifeImageId"></key>
</joined-subclass>
<joined-subclass name="com.newbeedaly.model.WorkImage3" table="t_workImage3">
<key column="workImageId"></key>
</joined-subclass>
</class>
</hibernate-mapping>