package com.levice.firsthibernate.bean;import java.util.Date;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.JoinColumn;import javax.persistence.ManyToOne;import javax.persistence.Table;import javax.persistence.Temporal;import javax.persistence.TemporalType;@Entity                              //注解Entity表示该类能被Hibernate持久化@Table(name = "tb_cat")              //指定该Entity对应的数据表名public class Cat {    @Id                              //指定该列为主键。主键类型最好不要使用int等原始类型    @GeneratedValue(strategy = GenerationType.AUTO) //主键类型auto表示该主键为自增长型    private Integer id;        @Column(name = "name")           //指定该属性对应的数据库表的列为name，列名与属性名一样时这句注解可省略    private String name;        @Column(name = "description")    private String description;        @ManyToOne                       //指定实体类之间的关系，本例表示多对一关系    @JoinColumn(name = "mother_id")    private Cat mother;        @Temporal(TemporalType.TIMESTAMP)//日期类型（DATE，TIME或TIMESTEMP）    @Column(name = "birthday")    private Date birthday;            //getters and setters    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 String getDescription() {        return description;    }    public void setDescription(String description) {        this.description = description;    }    public Cat getMother() {        return mother;    }    public void setMother(Cat mother) {        this.mother = mother;    }    public Date getBirthday() {        return birthday;    }    public void setBirthday(Date birthday) {        this.birthday = birthday;    }    }

<!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>        <!-- 配置JDBC -->        <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>                <!-- 指定使用MySQL数据库格式的SQL语句 -->        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>                <!-- 指定在控制台打印生成的SQL语句 -->        <property name="show_sql">true</property>                <!-- 指定Hibernate启动时自动创建表结构 -->        <property name="hbm2ddl.auto">create</property>                <!-- 加上这一句以防止未知错误 -->        <property name="current_session_context_class">thread</property>                <!-- 指定Cat类为Hibernate实体类 -->        <mapping class="com.levice.firsthibernate.bean.Cat"/>    </session-factory></hibernate-configuration>

create database hibernate;

package com.levice.firsthibernate.util;import org.hibernate.SessionFactory;import org.hibernate.cfg.AnnotationConfiguration;@SuppressWarnings("deprecation")public class HibernateUtil {    private static final SessionFactory sessionFactory;    static{        try{            sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();        }catch(Throwable ex){            System.err.println("Initial SessionFactory creation failed.");            throw new ExceptionInInitializerError(ex);        }    }        public static SessionFactory getSessionFactory(){        return sessionFactory;    }}

package com.levice.firsthibernate.test;import java.awt.Font;import java.util.Date;import java.util.List;import javax.swing.JOptionPane;import org.hibernate.Session;import org.hibernate.Transaction;import com.levice.firsthibernate.bean.Cat;import com.levice.firsthibernate.util.HibernateUtil;public class CatTest {    public static void main(String[] args) {        // TODO Auto-generated method stub        /*初始化几只Cat的信息*/        Cat mother = new Cat();        mother.setName("Mother White");        mother.setDescription("This is mother cat");        mother.setBirthday(new Date());        Cat kitty = new Cat();        kitty.setMother(mother);        kitty.setName("Kitty");        kitty.setDescription("This is Kitty");        kitty.setBirthday(new Date());        Cat tom = new Cat();        tom.setMother(mother);        tom.setName("Tom");        tom.setDescription("This is Tom");        tom.setBirthday(new Date());        @SuppressWarnings("static-access")        Session session = new HibernateUtil().getSessionFactory().openSession(); //获取session并open，开启一个Hibernate会话        Transaction trans = session.beginTransaction(); //开启一个事务        session.persist(mother); //将mother保存到数据库        session.persist(kitty);        session.persist(tom);        @SuppressWarnings("all")        List<Cat> catList = session.createQuery(" from Cat ").list(); //查询数据库中所有的猫        StringBuffer result = new StringBuffer();        result.append("all cats: \r\n\r\n");        for (Cat cc : catList) {            result.append("name:" + cc.getName() + "\n");            result.append("mother:" + (cc.getMother() == null ? "null" : cc.getMother().getName()) + "\n");            result.append("description:" + cc.getDescription() + "\r\n\r\n");        }        trans.commit(); //提交事务        session.close(); //关闭Hibernate会话        //用Swing显示查询结果        JOptionPane.getRootFrame().setFont(new Font("Arial", Font.BOLD, 14));        JOptionPane.showMessageDialog(null, result.toString());    }}

Hibernate: alter table tb_cat drop foreign key FK_dix3h50rxo8ahrcu5roir75n1Hibernate: drop table if exists tb_catHibernate: create table tb_cat (id integer not null auto_increment, birthday datetime, description varchar(255), name varchar(255), mother_id integer, primary key (id))Hibernate: alter table tb_cat add constraint FK_dix3h50rxo8ahrcu5roir75n1 foreign key (mother_id) references tb_cat (id)Hibernate: insert into tb_cat (birthday, description, mother_id, name) values (?, ?, ?, ?)Hibernate: insert into tb_cat (birthday, description, mother_id, name) values (?, ?, ?, ?)Hibernate: insert into tb_cat (birthday, description, mother_id, name) values (?, ?, ?, ?)Hibernate: select cat0_.id as id1_0_, cat0_.birthday as birthday2_0_, cat0_.description as descript3_0_, cat0_.mother_id as mother_i5_0_, cat0_.name as name4_0_ from tb_cat cat0_