Hibernate实战——Embedded注解-蒲公英云

一配置文件

<?xml version="1.0" encoding="GBK"?>
<!-- 指定Hibernate配置文件的DTD信息 -->
<!DOCTYPE hibernate-configuration PUBLIC
     "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
     "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<!-- hibernate-configuration是配置文件的根元素 -->
<hibernate-configuration>
     <session-factory>
           <!-- 指定连接数据库所用的驱动 -->
           <property  name="connection.driver_class">com.mysql.jdbc.Driver</property>
           <!-- 指定连接数据库的url，其中hibernate是本应用连接的数据库名 -->
           <property  name="connection.url">jdbc:mysql://localhost/hibernate</property>
           <!-- 指定连接数据库的用户名 -->
           <property name="connection.username">root</property>
           <!-- 指定连接数据库的密码 -->
           <property name="connection.password">32147</property>
           <!-- 指定连接池里最大连接数 -->
           <property  name="hibernate.c3p0.max_size">20</property>
           <!-- 指定连接池里最小连接数 -->
           <property name="hibernate.c3p0.min_size">1</property>
           <!-- 指定连接池里连接的超时时长 -->
           <property  name="hibernate.c3p0.timeout">5000</property>
           <!-- 指定连接池里最大缓存多少个Statement对象 -->
           <property  name="hibernate.c3p0.max_statements">100</property>
           <property  name="hibernate.c3p0.idle_test_period">3000</property>
           <property  name="hibernate.c3p0.acquire_increment">2</property>
           <property  name="hibernate.c3p0.validate">true</property>
           <!-- 指定数据库方言 -->
           <property  name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
           <!-- 根据需要自动创建数据库 -->
           <property name="hbm2ddl.auto">update</property>
           <!-- 显示Hibernate持久化操作所生成的SQL -->
           <property name="show_sql">true</property>
           <!-- 将SQL脚本进行格式化后再输出 -->
           <property name="hibernate.format_sql">true</property>
           <!-- 罗列所有持久化类的类名 -->
           <mapping class="org.crazyit.app.domain.Person"/>
     </session-factory>
</hibernate-configuration>

二 PO

1 Name

package org.crazyit.app.domain;
import org.hibernate.annotations.Parent;
public class Name
{
     // 定义first成员变量
     private String first;
     // 定义last成员变量
     private String last;
     // 引用拥有该Name的Person对象
     @Parent
     private Person owner;
     // 无参数的构造器
     public Name()
     {
     }
     // 初始化全部成员变量的构造器
     public Name(String first , String last)
     {
           this.first = first;
           this.last = last;
     }
     // first的setter和getter方法
     public void setFirst(String first)
     {
           this.first = first;
     }
     public String getFirst()
     {
           return this.first;
     }
     // last的setter和getter方法
     public void setLast(String last)
     {
           this.last = last;
     }
     public String getLast()
     {
           return this.last;
     }
     // owner的setter和getter方法
     public void setOwner(Person owner)
     {
           this.owner = owner;
     }
     public Person getOwner()
     {
           return this.owner;
     }
}

2 Person

package org.crazyit.app.domain;
import javax.persistence.*;
@Entity
@Table(name="person_inf")
public class Person
{
     @Id @Column(name="person_id")
     @GeneratedValue(strategy=GenerationType.IDENTITY)
     private Integer id;
     private int age;
     // 组件属性name
     @Embedded
     @AttributeOverrides({
           @AttributeOverride(name="first", column =  @Column(name="person_firstname")),
           @AttributeOverride(name="last", column =  @Column(name="person_lastname"))
     })
     private Name name;
     // id的setter和getter方法
     public void setId(Integer id)
     {
           this.id = id;
     }
     public Integer getId()
     {
           return this.id;
     }
     // age的setter和getter方法
     public void setAge(int age)
     {
           this.age = age;
     }
     public int getAge()
     {
           return this.age;
     }
     // name的setter和getter方法
     public void setName(Name name)
     {
           this.name = name;
     }
     public Name getName()
     {
           return this.name;
     }
}

三测试

1 工具类

package lee;
import org.hibernate.*;
import org.hibernate.cfg.*;
import org.hibernate.service.*;
import org.hibernate.boot.registry.*;
public class HibernateUtil
{
    public static final SessionFactory sessionFactory;
    static
    {
        try
        {
            // 使用默认的hibernate.cfg.xml配置文件创建Configuration实例
            Configuration cfg = new Configuration()
                .configure();
            // 以Configuration实例来创建SessionFactory实例
            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
                .applySettings(cfg.getProperties()).build();
            sessionFactory = cfg.buildSessionFactory(serviceRegistry);
        }
        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);
    }
}

2 测试类

package lee;
import org.hibernate.Transaction;
import org.hibernate.Session;
import java.util.Date;
import java.util.Set;
import java.util.HashSet;
import org.crazyit.app.domain.*;
public class PersonManager
{
    public static void main(String[] args)
    {
        PersonManager mgr = new PersonManager();
        mgr.createAndStorePerson();
        HibernateUtil.sessionFactory.close();
    }
    private void createAndStorePerson()
    {
        Session session = HibernateUtil.currentSession();
        Transaction tx = session.beginTransaction();
        // 创建Person对象
        Person person = new Person();
        // 为Person对象设置属性
        person.setAge(29);
        person.setName(new Name("crazyit.org" , "疯狂Java联盟"));
        session.save(person);
        tx.commit();
        HibernateUtil.closeSession();
    }
}