20151215 Hibernate学习笔记------基本的配置和使用方法

20151215 Hibernate学习笔记——基本的配置和使用方法

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Hibernate 基本配置

1. 下载 Hibernate

2. 导入jar包

将hibernate根目录\lib\required文件夹下的包全部导入,同时还需要导入数据库的驱动包.要注意的是因为要使用JPA标准的标签(需要import javax.persistence),所以还要导入jpa.jar包(百度一下下载即可).(看一些介绍说不用导此包也行,但我不导却报错了,待研究)

3. 配置xml文档

在中文html文档中有Hibernate.cfg.xml的示例,复制过来改即可.
修改后的配置文件如下:

<hibernate-configuration>

    <session-factory>

        
        <property name="connection.driver_class">com.mysql.jdbc.Driverproperty>
        <property name="connection.url">jdbc:mysql://localhost/hj_legendproperty>
        <property name="connection.username">rootproperty>
        <property name="connection.password">property>

        
        <property name="connection.pool_size">1property>

        
        <property name="dialect">org.hibernate.dialect.MySQLDialectproperty>

        
        <property name="current_session_context_class">threadproperty>

        
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProviderproperty>

        
        <property name="show_sql">trueproperty>

        
        <property name="hbm2ddl.auto">updateproperty>

        
        
        <mapping class="com.hj.hibernate.bean.User"/>

    session-factory>

hibernate-configuration>

4. 用注解配置javaBean

package com.hj.hibernate.bean;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;


@Entity//说明此类是一个持久化类
@Table(name = "tb_user")//说明对应的数据库表名
public class User
{
    @Id//说明此字段是id
    @GeneratedValue(strategy=GenerationType.IDENTITY)//id自动增长
    private int userId;//以下三个字段为了简便命名与数据库中的命名相同,这样就不用单独配置了
    private String userName;
    private String password;

    public User()
    {
        super();
    }
    public User(String userName, String password)
    {
        super();
        this.userName = userName;
        this.password = password;
    }
    public int getId()
    {
        return userId;
    }
    public void setId(int id)
    {
        this.userId = id;
    }
    public String getUserName()
    {
        return userName;
    }
    public void setUserName(String userName)
    {
        this.userName = userName;
    }
    public String getPassword()
    {
        return password;
    }
    public void setPassword(String password)
    {
        this.password = password;
    }


}

用Hibernate操作数据库

基本步骤:

1. 获取Configuraction
2. 获取SessionFactory
3. 获取session并开始事务
4. 用面向对象的方法操作数据库
5. 关闭资源

java代码如下(向tb_user表中添加一条记录):

package com.hj.hibernate.test;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

import com.hj.hibernate.bean.User;
/**
 * 12/15/2015 11:06:15 AM 
 * @author HangJian
 *
 */
public class Main
{

    /**
     * @param args
     */
    public static void main(String[] args)
    {
        //获得配置
        Configuration cfg = new Configuration().configure();
        //获取sessionFactory
        SessionFactory sf = cfg.buildSessionFactory();
        //创建session
        Session sess = sf.openSession();
        //开始事务
        Transaction ts = sess.beginTransaction();
        //创建实体类的对象
        User user = new User("hjhjhjhjhjhj", "123");
        //保存
        sess.save(user);
        //提交事务
        ts.commit();
        //关闭session
        sess.close();
        sf.close();/**/


    }

}