搭建一个单纯学习hibernate的项目

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>crazyjava</groupId>
    <artifactId>hibernateTest</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>hibernateTest</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
            <scope>test</scope>
        </dependency>
       <!-- mysql的依赖包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>
        <!-- Hibernate的依赖包 -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>4.3.11.Final</version>
        </dependency>
        <!-- log4j -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>
</project>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.password">root</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
        <property name="hbm2ddl.auto">update</property>
        <property name="show_sql">true</property>        
        <mapping class="org.crazyit.app.domain.News"/>
        <mapping class="org.crazyit.app.domain.Person"/>
        <mapping class="org.crazyit.app.domain.Address"/>
    </session-factory>
</hibernate-configuration>

第二个是hbm文件 hibernate.cfg.xml

下面是hibernatutils

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);
	}
}

　　

下面是实体类和测试类

package lee;

import org.hibernate.*;
import org.hibernate.cfg.*;
import org.hibernate.service.*;
import org.hibernate.boot.registry.*;
import org.crazyit.app.domain.*;


public class NewsManager
{
    public static void main(String[] args)
        throws Exception
    {
        // 实例化Configuration，
        Configuration conf = new Configuration()
        // 不带参数的configure()方法默认加载hibernate.cfg.xml文件，
        // 如果传入abc.xml作为参数，则不再加载hibernate.cfg.xml，改为加载abc.xml
            .configure();
        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
            .applySettings(conf.getProperties()).build();
        // 以Configuration实例创建SessionFactory实例
        SessionFactory sf = conf.buildSessionFactory(serviceRegistry);
        // 创建Session
        Session sess = sf.openSession();
        // 开始事务
        Transaction tx = sess.beginTransaction();
        // 创建消息对象
        News n = new News();
        // 设置消息标题和消息内容
        n.setTitle("疯狂Java联盟成立了");
        n.setContent("疯狂Java联盟成立了，"
            + "网站地址http://www.crazyit.org");
        // 保存消息
        sess.save(n);
        // 提交事务
        tx.commit();
        // 关闭Session
        sess.close();
        sf.close();
    }
}

package org.crazyit.app.domain;

import javax.persistence.*;

@Entity
@Table(name="news_inf")
public class News
{
    // 消息类的标识属性
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Integer id;
    // 消息标题
    private String title;
    // 消息内容
    private String content;

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

    // title的setter和getter方法
    public void setTitle(String title)
    {
        this.title = title;
    }
    public String getTitle()
    {
        return this.title;
    }

    // content的setter和getter方法
    public void setContent(String content)
    {
        this.content = content;
    }
    public String getContent()
    {
        return this.content;
    }
}

package org.crazyit.app.domain;

import lee.HibernateUtil;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

public class TestQuery {
    private Session session = null;
    private Transaction tx = null;

    @Before
    public void before() {
        session = HibernateUtil.currentSession();
        tx = session.beginTransaction();
    }
    @Test
    public void test1() {
        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);
        a.setPerson(p);
        // 持久化Address对象
        session.persist(a);
        // 持久化Person对象
        session.save(p);
    }

    @After
    public void after() {
        tx.commit();
        HibernateUtil.closeSession();
    }
}

使用junit更好