hibernate聚合类型映射_Java相关

hibernate集合类型映射

Set无序元素不可重复

List有序元素可重复

Bag无序元素可重复

Map键值对

Student:

package model;

import java.util.Set;

public class Student {
   private long id;
   private String name;
   private Set<String> images;
   public long getId() {
       return id;
   }
   public void setId(long id) {
       this.id = id;
   }
   public String getName() {
       return name;
   }
   public void setName(String name) {
       this.name = name;
   }
   public Set<String> getImages() {
       return images;
   }
   public void setImages(Set<String> images) {
       this.images = images;
   }


}

<?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="model">

   <class name="Student" table="t_student">
       <id name="id" column="stuId">
           <generator class="native"></generator>
       </id>

       <property name="name" column="stuName"></property>

       <set name="images" table="t_image">
           <key column="studentId"></key>
           <element column="imageName" type="string"></element>
       </set>
   </class>

</hibernate-mapping>

Student2:

package model;

import java.util.List;

public class Student2 {
   private long id;
   private String name;
   private List<String> images;
   public long getId() {
       return id;
   }
   public void setId(long id) {
       this.id = id;
   }
   public String getName() {
       return name;
   }
   public void setName(String name) {
       this.name = name;
   }
   public List<String> getImages() {
       return images;
   }
   public void setImages(List<String> images) {
       this.images = images;
   }



}

<?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="model">

   <class name="Student2" table="t_student">
       <id name="id" column="stuId">
           <generator class="native"></generator>
       </id>

       <property name="name" column="stuName"></property>

       <list name="images" table="t_image2">
           <key column="studentId"></key>
           <list-index column="imageIndex"></list-index>
           <element column="imageName" type="string"></element>
       </list>
   </class>

</hibernate-mapping>

Student3:

package model;

import java.util.List;

public class Student3 {
   private long id;
   private String name;
   private List<String> images;
   public long getId() {
       return id;
   }
   public void setId(long id) {
       this.id = id;
   }
   public String getName() {
       return name;
   }
   public void setName(String name) {
       this.name = name;
   }
   public List<String> getImages() {
       return images;
   }
   public void setImages(List<String> images) {
       this.images = images;
   }



}

<?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="model">

   <class name="Student3" table="t_student">
       <id name="id" column="stuId">
           <generator class="native"></generator>
       </id>

       <property name="name" column="stuName"></property>

       <idbag name="images" table="t_image3">
           <collection-id type="long" column="imageId">
               <generator class="increment"></generator>
           </collection-id>
           <key column="studentId"></key>
           <element column="imageName" type="string"></element>
       </idbag>
   </class>

</hibernate-mapping>

Student4:

package model;

import java.util.Map;

public class Student4 {
   private long id;
   private String name;
   private Map<String,String>images;
   public long getId() {
       return id;
   }
   public void setId(long id) {
       this.id = id;
   }
   public String getName() {
       return name;
   }
   public void setName(String name) {
       this.name = name;
   }
   public Map<String, String> getImages() {
       return images;
   }
   public void setImages(Map<String, String> images) {
       this.images = images;
   }


}

<?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="model">

   <class name="Student4" table="t_student">
       <id name="id" column="stuId">
           <generator class="native"></generator>
       </id>

       <property name="name" column="stuName"></property>

       <map name="images" table="t_image4">
           <key column="studentId"></key>
           <map-key type="string" column="imageKey"></map-key>
           <element column="imageName" type="string"></element>
       </map>
   </class>

</hibernate-mapping>

StudentTest:

package service;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
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 util.HibernateUtil;
import model.Student;
import model.Student2;
import model.Student3;
import model.Student4;

public class StudentTest {

   SessionFactory sessionfactory=HibernateUtil.getSessionFactory();//获取Session工厂
   private Session session;

   @Before
   public void setUp() throws Exception {
       session=sessionfactory.openSession();//生成一个新的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 testSetSave(){
       Set<String> imageSet=new HashSet<String>();
       imageSet.add("image1.png");
       imageSet.add("image2.png");
       imageSet.add("image3.png");
       imageSet.add("image4.png");
       Student s1=new Student();
       s1.setImages(imageSet);
       session.save(s1);
   }

   @Test
   public void testSetFetch(){
       Student student=(Student) session.get(Student.class,Long.valueOf(1));
       Iterator it=student.getImages().iterator();
       while(it.hasNext()){
           System.out.println(it.next());
       }
   }

   @Test
   public void testListSave(){
       List<String> imageList=new ArrayList<String>();
       imageList.add("image1.png");
       imageList.add("image2.png");
       imageList.add("image3.png");
       imageList.add("image4.png");

       Student2 s2=new Student2();
       s2.setImages(imageList);
       session.save(s2);
   }

   @Test
   public void testListFetch(){
       Student2 student2=(Student2) session.get(Student2.class,Long.valueOf(2));
       Iterator it=student2.getImages().iterator();
       while(it.hasNext()){
           System.out.println(it.next());
       }
   }

   @Test
   public void testBagSave(){
       List<String> imageList=new ArrayList<String>();
       imageList.add("image1.png");
       imageList.add("image2.png");
       imageList.add("image3.png");
       imageList.add("image4.png");

       Student3 s3=new Student3();
       s3.setImages(imageList);
       session.save(s3);
   }

   @Test
   public void testBagFetch(){
       Student3 student3=(Student3) session.get(Student3.class,Long.valueOf(3));
       Iterator it=student3.getImages().iterator();
       while(it.hasNext()){
           System.out.println(it.next());
       }
   }

   @Test
   public void testMapSave(){
       Map<String,String>imageMap=new HashMap<String,String>();
       imageMap.put("i1","image1.png");
       imageMap.put("i2","image2.png");
       imageMap.put("i3","image3.png");
       imageMap.put("i4","image4.png");

       Student4 s4=new Student4();
       s4.setImages(imageMap);
       session.save(s4);
   }

   @Test
   public void testMapFetch(){
       Student4 student4=(Student4) session.get(Student4.class,Long.valueOf(4));
       Map<String,String>imageMap=student4.getImages();
       Set keys=imageMap.keySet();
       Iterator it=keys.iterator();
       while(it.hasNext()){
           String key=(String) it.next();
           System.out.println(key+":"+imageMap.get(key));
       }
   }
}