（七）Hibernate 映射继承

所有项目导入对应的hibernate的jar包、mysql的jar包和添加每次都需要用到的HibernateUtil.java

第一节：每个具体类对应一个表

Image.java

 package com.wishwzp.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;
     }
 }

WorkImage.java

 package com.wishwzp.model;

 public class WorkImage extends Image{

 }

LifeImage.java

 package com.wishwzp.model;

 public class LifeImage extends Image{

 }

Student.java

 package com.wishwzp.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;
     }
 }

hibernate.cfg.xml

 <?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/wishwzp/model/Student.hbm.xml"/>
           <mapping resource="com/wishwzp/model/LifeImage.hbm.xml"/>
           <mapping resource="com/wishwzp/model/WorkImage.hbm.xml"/>

     </session-factory>

 </hibernate-configuration>

StudentTest.java

 package com.wishwzp.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.wishwzp.model.Image;
 import com.wishwzp.model.Image2;
 import com.wishwzp.model.Image3;
 import com.wishwzp.model.Student2;
 import com.wishwzp.model.Student3;
 import com.wishwzp.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(){

     }
 }

WorkImage.java和LifeImage.java继承了 Image.java，我们在数据库里面可以看出来的。

这里我们在向数据库里面插入一些数据。。。

向t_student表中插入stuName为张三:

向t_lifeimage表中插入imageName:

向t_workimage表中插入imageName:

然后我们查询这些数据：

StudentTest.java

 package com.wishwzp.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.wishwzp.model.Image;
 import com.wishwzp.model.Image2;
 import com.wishwzp.model.Image3;
 import com.wishwzp.model.Student2;
 import com.wishwzp.model.Student3;
 import com.wishwzp.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());
         }
     }
 }

控制台显示：

第二节：根类对应一个表

image2.java

 package com.wishwzp.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;
     }
 }

LifeImage2.java

 package com.wishwzp.model;

 public class LifeImage2 extends Image2{

 }

WorkImage2.java

 package com.wishwzp.model;

 public class WorkImage2 extends Image2{

 }

Student2.java

 package com.wishwzp.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;
     }

 }

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.wishwzp.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.wishwzp.model.Student2"></many-to-one>

         <subclass name="com.wishwzp.model.LifeImage2" discriminator-value="li"></subclass>
         <subclass name="com.wishwzp.model.WorkImage2" discriminator-value="wi"></subclass>
     </class>

 </hibernate-mapping>

Student2.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.wishwzp.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.wishwzp.model.Image2"/>
         </set>
     </class>

 </hibernate-mapping>

hibernate.cfg.xml

 <?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/wishwzp/model/Student2.hbm.xml"/>
           <mapping resource="com/wishwzp/model/Image2.hbm.xml"/>

     </session-factory>

 </hibernate-configuration>

StudentTest.java

 package com.wishwzp.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.wishwzp.model.Image;
 import com.wishwzp.model.Image2;
 import com.wishwzp.model.Image3;
 import com.wishwzp.model.Student2;
 import com.wishwzp.model.Student3;
 import com.wishwzp.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 testGetAllImages2(){

     }
 }

插入数据：

然后查询这些数据：

StudentTest.java

 package com.wishwzp.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.wishwzp.model.Image;
 import com.wishwzp.model.Image2;
 import com.wishwzp.model.Image3;
 import com.wishwzp.model.Student2;
 import com.wishwzp.model.Student3;
 import com.wishwzp.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 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());
         }
     }
 }

控制台显示：

第三节：每个类对应一个表

Student3.java

 package com.wishwzp.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;
     }

 }

Image3.java

 package com.wishwzp.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;
     }

 }

LifeImage3.java

 package com.wishwzp.model;

 public class LifeImage3 extends Image3{

 }

WorkImage3.java

 package com.wishwzp.model;

 public class WorkImage3 extends Image3{

 }

Student3.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.wishwzp.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.wishwzp.model.Image3"/>
         </set>
     </class>

 </hibernate-mapping>

Image3.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.wishwzp.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.wishwzp.model.Student3"></many-to-one>

         <joined-subclass name="com.wishwzp.model.LifeImage3" table="t_lifeImage3">
             <key column="lifeImageId"></key>
         </joined-subclass>

         <joined-subclass name="com.wishwzp.model.WorkImage3" table="t_workImage3">
             <key column="workImageId"></key>
         </joined-subclass>
     </class>

 </hibernate-mapping>

hibernate.cfg.xml

 <?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/wishwzp/model/Student3.hbm.xml"/>
           <mapping resource="com/wishwzp/model/Image3.hbm.xml"/>

     </session-factory>

 </hibernate-configuration>

StudentTest.java

 package com.wishwzp.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.wishwzp.model.Image;
 import com.wishwzp.model.Image2;
 import com.wishwzp.model.Image3;
 import com.wishwzp.model.Student2;
 import com.wishwzp.model.Student3;
 import com.wishwzp.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 testGetAllImages3(){

     }
 }

插入一些数据：

然后查询这些数据：

StudentTest.java

 package com.wishwzp.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.wishwzp.model.Image;
 import com.wishwzp.model.Image2;
 import com.wishwzp.model.Image3;
 import com.wishwzp.model.Student2;
 import com.wishwzp.model.Student3;
 import com.wishwzp.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 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());
         }
     }
 }

控制台显示：