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：HibernateSet集合属性

<?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"/>
    </session-factory>
</hibernate-configuration>

package lee;

import org.hibernate.*;
import org.hibernate.service.*;
import org.hibernate.boot.registry.*;
import org.hibernate.cfg.*;

/**
 * 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.createAndStorePerson();
        HibernateUtil.sessionFactory.close();
    }

    private void createAndStorePerson()
    {
        Session session = HibernateUtil.currentSession();
        Transaction tx = session.beginTransaction();
        // 创建Person对象
        Person person = new Person();
        person.setAge(20);
        person.setName("crazyit.org");
        // 向person的schools集合属性中添加两个字符串元素
        person.getSchools().add("小学");
        person.getSchools().add("中学");
        session.save(person);
        tx.commit();
        HibernateUtil.closeSession();
    }
}

package org.crazyit.app.domain;

import java.util.Set;
import java.util.HashSet;
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
{
    @Id @Column(name="person_id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    // 标识属性
    private Integer id;
    private String name;
    private int age;
    // 集合属性，保留该对象关联的学校
    @ElementCollection(targetClass=String.class)
    // 映射保存集合属性的表
    @CollectionTable(name="school_inf", // 指定表名为school_inf
        joinColumns=@JoinColumn(name="person_id" , nullable=false))
    // 指定保存集合元素的列为 school_name，nullable=false增加非空约束
    @Column(name="school_name" , nullable=false)
    private Set<String> schools
        = new HashSet<>();

    // 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;
    }

    // schools的setter和getter方法
    public void setSchools(Set<String> schools)
    {
        this.schools = schools;
    }
    public Set<String> getSchools()
    {
        return this.schools;
    }

}