吴裕雄--天生自然轻量级JAVA EE企业应用开发Struts2Sping4Hibernate整合开发学习笔记：Hibernate_unidirectional_N-1jointable

<?xml version="1.0" encoding="GBK"?>
<project name="hibernate" basedir="." default="">
    <property name="src" value="src"/>
    <property name="dest" value="classes"/>

    <path id="classpath">
        <fileset dir="../../../lib">
            <include name="**/*.jar"/>
        </fileset>
        <pathelement path="${dest}"/>
    </path>

    <target name="compile" description="Compile all source code">
        <delete dir="${dest}"/>
        <mkdir dir="${dest}"/>
        <copy todir="${dest}">
            <fileset dir="${src}">
                <exclude name="**/*.java"/>
            </fileset>        
        </copy>
        <javac destdir="${dest}" debug="true" includeantruntime="yes"
            deprecation="false" optimize="false" failonerror="true">
            <src path="${src}"/>
            <classpath refid="classpath"/>
            <compilerarg value="-Xlint:deprecation"/>
        </javac>
    </target>

    <target name="run" description="Run the main class" depends="compile">
        <java classname="lee.PersonManager" fork="yes" failonerror="true">
            <classpath refid="classpath"/>
        </java>
    </target>

</project>

<?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"/>
        <mapping class="org.crazyit.app.domain.Address"/>
    </session-factory>
</hibernate-configuration>

package org.crazyit.app.domain;

import java.util.*;

import javax.persistence.*;
/**
 * Description:
 * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>
 * <br/>Copyright (C), 2001-2016, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee kongyeeku@163.com
 * @version  1.0
 */
@Entity
@Table(name="address_inf")
public class Address
{
    // 标识属性
    @Id @Column(name="address_id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int addressId;
    // 定义地址详细信息的成员变量
    private String addressDetail;

    // 无参数的构造器
    public Address()
    {
    }
    // 初始化全部成员变量的构造器
    public Address(String addressDetail)
    {
        this.addressDetail = addressDetail;
    }

    // addressId的setter和getter方法
    public void setAddressId(int addressId)
    {
        this.addressId = addressId;
    }
    public int getAddressId()
    {
        return this.addressId;
    }

    // addressDetail的setter和getter方法
    public void setAddressDetail(String addressDetail)
    {
        this.addressDetail = addressDetail;
    }
    public String getAddressDetail()
    {
        return this.addressDetail;
    }
}

package org.crazyit.app.domain;

import java.util.*;

import javax.persistence.*;
/**
 * Description:
 * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>
 * <br/>Copyright (C), 2001-2016, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee kongyeeku@163.com
 * @version  1.0
 */
@Entity
@Table(name="person_inf")
public class Person
{
    // 标识属性
    @Id @Column(name="person_id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Integer id;
    private String name;
    private int age;
    // 定义该Person实体关联的Address实体
    @ManyToOne(targetEntity=Address.class)
    // 显式使用@JoinTable映射连接表
    @JoinTable(name="person_address", // 指定连接表的表名为person_address
        // 指定连接表中person_id外键列，参照到当前实体对应表的主键列
        joinColumns=@JoinColumn(name="person_id"
            , referencedColumnName="person_id", unique=true),
        // 指定连接表中address_id外键列，参照到当前实体的关联实体对应表的主键列
        inverseJoinColumns=@JoinColumn(name="address_id"
            , referencedColumnName="address_id")
    )
    private Address address;

    // id的setter和getter方法
    public void setId(Integer id)
    {
        this.id = id;
    }
    public Integer getId()
    {
        return this.id;
    }

    // name的setter和getter方法
    public void setName(String name)
    {
        this.name = name;
    }
    public String getName()
    {
        return this.name;
    }

    // age的setter和getter方法
    public void setAge(int age)
    {
        this.age = age;
    }
    public int getAge()
    {
        return this.age;
    }

    // address的setter和getter方法
    public void setAddress(Address address)
    {
        this.address = address;
    }
    public Address getAddress()
    {
        return this.address;
    }
}

package lee;

import org.hibernate.*;
import org.hibernate.cfg.*;
import org.hibernate.service.*;
import org.hibernate.boot.registry.*;
/**
 * Description:
 * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>
 * <br/>Copyright (C), 2001-2016, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee kongyeeku@163.com
 * @version  1.0
 */
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);
    }
}

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.*;
/**
 * Description:
 * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>
 * <br/>Copyright (C), 2001-2016, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee kongyeeku@163.com
 * @version  1.0
 */
public class PersonManager
{
    public static void main(String[] args)
    {
        PersonManager mgr = new PersonManager();
        mgr.testPerson();
        HibernateUtil.sessionFactory.close();
    }

    private void testPerson()
    {
        Session session = HibernateUtil.currentSession();
        Transaction tx = session.beginTransaction();
        // 创建一个Person对象
        Person p = new Person();
        // 设置Person的name为crazyit字符串
        p.setName("crazyit");
        p.setAge(21);
        // 创建一个瞬态的Address对象
        Address a = new Address("广州天河");
        // 设置Person和Address之间的关联关系
        p.setAddress(a);
        // 再持久化Address对象
        session.persist(a);
        // 创建一个瞬态的Address对象
        Address a2 = new Address("上海虹口");
        // 设置Person和Address之间的关联关系
        p.setAddress(a2);
        // 由于采用了连接表来维护N-1关联关系，因此不存在主从表关系，
        // 程序可以随意控制先持久化哪个实体。
        // 持久化Address对象
        session.persist(a2);
        // 持久化Person对象
        session.save(p);
        // 持久化Address对象
        session.save(a);
        tx.commit();
        HibernateUtil.closeSession();
    }
}