Hibernate学习7—Hibernate 映射继承

时间：2017-07-29 16:44:46 阅读：176 评论：0 收藏：0 [点我收藏+]

标签：pac images port e30 技术 system setname pre student

需求：学生有很多照片，分为生活照和工作照；

第一节：每个具体类对应一个表　　　　　　　　　　　　　　　　　　　　　　　　

Student.java:

package com.cy.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;
    }
    
    
    
}

View Code

抽象类Image.java:

package com.cy.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;
    }
    
    
}

View Code

生活照LifeImage.java:

package com.cy.model;

public class LifeImage extends Image{

}

View Code

工作照WorkImage.java:

package com.cy.model;

public class WorkImage extends Image{

}

View Code

Student.hbm.xml:

<hibernate-mapping package="com.cy.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>

LifeImage.hbm.xml:

<hibernate-mapping package="com.cy.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.cy.model.Student"></many-to-one>
    </class>

</hibernate-mapping>

View Code

WorkImage.hbm.xml:

<hibernate-mapping package="com.cy.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.cy.model.Student"></many-to-one>
    </class>

</hibernate-mapping>

View Code

测试代码StudentTest.java:

    @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);
        for(Image image: imageList){
            System.out.println(image.getImageName());
        }
        
    }

View Code

三个表的关联关系：

技术分享