package bean;import java.util.Date;public class Person {    private Integer id;    private String name;    private int password;    private Date birthday;        public Person()    {            }    @Override    public String toString() {        return "Person [id=" + id + ", name=" + name + ", password=" + password                + ", birthday=" + birthday + "]";    }    public Integer getId() {        return id;    }    public void setId(Integer id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public int getPassword() {        return password;    }    public void setPassword(int password) {        this.password = password;    }    public Date getBirthday() {        return birthday;    }    public void setBirthday(Date birthday) {        this.birthday = birthday;    }                }

package bean;public class Student extends Person{	private int classId;	private String className;	private int course;	@Override	public String toString() {		return "Student [classId=" + classId + ", className=" + className				+ ", course=" + course + ", getId()=" + getId()				+ ", getName()=" + getName() + ", getPassword()="				+ getPassword() + ", getBirthday()=" + getBirthday() + "]";	}	public int getClassId() {		return classId;	}	public void setClassId(int classId) {		this.classId = classId;	}	public String getClassName() {		return className;	}	public void setClassName(String className) {		this.className = className;	}	public int getCourse() {		return course;	}	public void setCourse(int course) {		this.course = course;	}			}

<?xml version="1.0"?><!DOCTYPE hibernate-mapping SYSTEM "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd" ><!-- 单表继承关系  配置实现     因为是多个子类都存储在 同一张表中，为了区分不同的子类，单表继承策略使用了一个 辨别列（discriminator）    注意：discriminator 辨别列一定要定义在 id 后面，紧跟id配置    type="string" 指定辨别列类型  column="type_id" 辨别列名称        通过subclass引入 子类     --><hibernate-mapping package="bean">    <class name="Person" table="t_person" >        <id name="id"><generator class="identity"/></id>        <discriminator type="string" column="type_id"/>        <property name="name"/>        <property name="password"/>        <property name="birthday"/>                <subclass name="Student">            <property name="classId"/>            <property name="className"/>            <property name="course"/>        </subclass>    </class>    </hibernate-mapping>

<!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>        <!-- 显示执行SQL语句 -->        <property name="show_sql">true</property>         <!-- 格式化SQL语句 -->        <property name="format_sql">false</property>        <!-- 驱动 -->        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>        <!-- 数据库url-->        <property name="hibernate.connection.url">jdbc:mysql:///hibernate_db</property>        <!-- 访问数据库用户名 -->        <property name="hibernate.connection.username">root</property>        <!-- 访问数据库密码 -->        <property name="hibernate.connection.password">root</property>        <!-- 方言（为了更好的操作具体的数据库）             如果使用的mysql数据版本在5.5之后的话，方言通常建议使用MySQL5InnoDBDialect            MySQLDialect 不支持事务            MySQLInnoDBDialect 支持事务         -->        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>        <!-- 自动创建表结构配置            create-drop 在程序启动的时候创建对应数据库表结构，当SessionFatory关闭的时候会将创建的表结构删除            create 在每次程序启动的时候先删除上次创建的数据库表结构，然后再创建对应新数据库表结构。            update 在每次启动的时候会追加修改的表结构，但是不会影响原来的数据 （通常用这个）            validate 在每次启动的时候会验证并修改的表结构。         -->        <property name="hibernate.hbm2ddl.auto">update</property>                <!-- 引入对应的需要持久化类的配置文件 -->        <mapping resource="bean/Person.hbm.xml"/>            </session-factory></hibernate-configuration>

package Test;import bean.Person;import bean.Student;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.hibernate.service.ServiceRegistry;import org.hibernate.service.ServiceRegistryBuilder;public class HibernateTest {    SessionFactory  sessionFactory =null;    Session session =null;    Transaction tx = null;    /**     * 初始化测试数据      * @throws Exception     */    public void setUp() throws Exception {        System.out.println("------setUp---初始化测试资源-----");        Configuration config = new Configuration().configure();        ServiceRegistry sr = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();        sessionFactory = config.buildSessionFactory(sr);        session = sessionFactory.openSession();    }            public void testAdd(){        Person p = new Person();        p.setName("tom");        p.setPassword(123456);        p.setBirthday(new java.util.Date());        tx = session.beginTransaction();            session.persist(p);        tx.commit();    }            public void testAdd2(){        Student stu = new Student();        stu.setName("stu");        stu.setPassword(123456);        stu.setBirthday(new java.util.Date());        stu.setClassId(1206);        stu.setClassName("J1206");        stu.setCourse(90);        tx = session.beginTransaction();            session.persist(stu);        tx.commit();    }            public void testGet(){                Person p = (Person)session.get(Person.class, 1);                System.out.println(p);            }        public void testGet2(){                Student stu = (Student)session.get(Student.class, 2);                System.out.println(stu);            }            /**     * 释放测试数据      * @throws Exception     */        public void tearDown() throws Exception {        System.out.println("------tearDown---释放测试数据---");        session.close();        sessionFactory.close();    }        public static void main(String [] args) throws Exception    {        HibernateTest h = new HibernateTest();        h.setUp();        h.testAdd2();        h.tearDown();    }}