Hibernate要做的就是将数据库中的表映射成Java中的POJO类，这样就可以像操作类一样来操作数据库对象了

常见的ORM 框架:

Hibernate 

iBATIS….

Hibernate需要8个jar文件 注意hibernate3.jar需要加上这是核心类库

<?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>

<!--数据库连接设置-->

<property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>

<property name="connection.url">jdbc:oracle:thin:@localhost:1521:sky</property>

<property name="connection.username">scott</property>

<property name="connection.password">tiger</property>

<!--JDBC数据库连接池-->

<property name="connection.pool_size">2</property>

<!--数据库方言-->

<property name="dialect">org.hibernate.dialect.Oracle9Dialect</property>

<!--可以将session绑定到特定的事务上-->

<property name="current_session_context_class">thread</property>

<!--输出数据库操作的SQL语句-->

<property name="show_sql">true</property>

<property name="format_sql">true</property>

<!-- 指向表和类的映射文件 -->

<mapping resource="org/cgz/hibernate/GuestBook.hbm.xml" />

</session-factory>

</hibernate-configuration>

<?xml version="1.0"?>

<!DOCTYPE hibernate-mapping PUBLIC

"-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="org.cgz.hibernate">

<class name="GuestBook" table="GuestBook" lazy="true">

<id name="id">

<generator class="sequence">

<param name="sequence">gb_seq</param>

</generator>

</id>

<property name="name" column="" type="java.lang.String" ></property>

<property name="email" column="" type="java.lang.String" ></property>

<property name="phone" column="" type="java.lang.String" ></property>

<property name="title" column="" type="java.lang.String" ></property>

<property name="content" column="" type="java.lang.String" ></property>

<property name="createdTime" column="created_time" type="java.util.Date" ></property>

</class>

</hibernate-mapping>

import java.util.Date;

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.Transaction;

import org.hibernate.cfg.Configuration;

publicclass HibernateTest {

publicstaticvoid main(String[] args) {

//生成JavaBean对象

GuestBook gBook = new GuestBook();

//赋值

gBook.setName("Jack");

gBook.setPhone("15855770982");

gBook.setEmail("login8226@126.com");

gBook.setTitle("我的第一个Hibernate程序");

gBook.setContent("我很Happy");

gBook.setCreatedTime(new Date());

//负责加载配置文件

Configuration config = new Configuration();

//完成配置的读取

config.configure();

//操作对应的数据库

SessionFactory sessionFactory = config.buildSessionFactory();

//和JDBC中的Connection对象类似

Session session = sessionFactory.getCurrentSession();

//事务启动事务

Transaction tx = session.beginTransaction();

//保存修改

session.save(gBook);

//提交事务

tx.commit();

}

}