【hibernate】映射集合属性list

代码组织：



数据库：一个人可以再多个学校学习



======================================================================================================================

package po;

import java.util.ArrayList;

import java.util.List;

/**

* Person entity. @author MyEclipse Persistence Tools

*/

public class Person implements java.io.Serializable {

// Fields

private Integer id;

private String name;

private Integer age;

private List<String> schools=new ArrayList<String>(); //List必须初始化，否则程序运行是抛空指针异常

// Constructors

/** default constructor */

public Person() {

}

/** full constructor */

public Person(String name, Integer age) {

this.name = name;

this.age = age;

}

// Property accessors

public Integer getId() {

return this.id;

}

public void setId(Integer id) {

this.id = id;

}

public String getName() {

return this.name;

}

public void setName(String name) {

this.name = name;

}

public Integer getAge() {

return this.age;

}

public void setAge(Integer age) {

this.age = age;

}

public List<String> getSchools() {

return schools;

}

public void setSchools(List<String> schools) {

this.schools = schools;

}

}

===============================================================================

<?xml version="1.0" encoding="utf-8"?>

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<!--

Mapping file autogenerated by MyEclipse Persistence Tools

-->

<hibernate-mapping>

<class name="po.Person" table="person" catalog="hibernate">

<id name="id" type="java.lang.Integer">

<column name="id" />

<generator class="identity" />

</id>

<property name="name" type="java.lang.String">

<column name="name" length="20" not-null="true" />

</property>

<property name="age" type="java.lang.Integer">

<column name="age" not-null="true" />

</property>

<list name="schools" table="school">

<key column="person_id" not-null="true"/>

<list-index column="list_order"/>

<element type="string" column="school_name"/>

</list>

</class>

</hibernate-mapping>

============================================================================

import org.hibernate.HibernateException;

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.cfg.Configuration;

public class HibernateUtil

{

public static final SessionFactory sessionFactory;

static

{

try

{

//采用默认的hibernate.cfg.xml来启动一个Configuration的实例

Configuration configuration = new Configuration()

.configure();

//由Configuration的实例来创建一个SessionFactory实例

sessionFactory = configuration.buildSessionFactory();

}

catch (Throwable ex)

{

System.err.println("Initial SessionFactory creation failed." + ex);

throw new ExceptionInInitializerError(ex);

}

}

//ThreadLocal可以隔离多个线程的数据共享，因此不再需要对线程同步

public static final ThreadLocal<Session> session

= new ThreadLocal<Session>();

public static Session currentSession()

throws HibernateException

{

Session s = session.get();

//如果该线程还没有Session,则创建一个新的Session

if (s == null)

{

s = sessionFactory.openSession();

//将获得的Session变量存储在ThreadLocal变量session里

session.set(s);

}

return s;

}

public static void closeSession()

throws HibernateException

{

Session s = session.get();

if (s != null)

s.close();

session.set(null);

}

}

============================================================================================

import java.util.ArrayList;

import java.util.List;

import org.hibernate.Session;

import org.hibernate.Transaction;

import po.Person;

public class T {

/**

* @param args

*/

public static void main(String[] args) {

Person yeeku= new Person();

yeeku.setName("dsfdg");

yeeku.setAge(20);

List<String> schools=new ArrayList<String>();

schools.add("小学");

schools.add("中学");

yeeku.setSchools(schools);

{

Session sess = HibernateUtil.currentSession();

Transaction tx = sess.beginTransaction();

sess.save(yeeku);

tx.commit();

HibernateUtil.closeSession();

}

}

}

运行结果：