hibernate------初识

1.创建db_hibernate数据库，在创建的数据库中创建一个students表

2.创建一个Java项目（项目中添加hibernate所需类库）

 

3.项目中添加hibernate.cfg.xml配置文件，完善配置信息

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- 数据库连接文件 -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/db_hibernate</property>
<property name="connection.username">root</property>
<property name="connection.password">775297</property>
<!-- 数据库连接池 -->
<property name="connection.pool_size">1</property>
<!-- sql方言 -->
<property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
<!-- session环境 -->
<property name="current_session_context_class">thread</property>
<!-- 打印sql语句 -->
<property name="show_sql">true</property>
<!-- 格式化SQL语句 -->
<property name="format_sql">true</property>
<!-- 加载配置文件 -->
<mapping resource="com/zdsofe/hibernate/Student.hbm.xml"/>
</session-factory>
</hibernate-configuration>    
    

4.创建Student实体类，为该类提供私有属性和get/set方法

package com.zdsofe.hibernate;

import java.util.Date;

public class Student {
 
    private int id;
    private String name;
    private String sex;
    private Date birthday;

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public Date getBirthday() {
        return birthday;
    }
    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
    
    
}

5.在Student类的包下添加一个映射文件Student.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
  
<hibernate-mapping package="com.zdsofe.hibernate">
  <!-- 定义实体类与数据库之间的映射 -->
  <class name="Student" table="students">
      <!--定义表主键与属性之间的映射关系 -->
      <id name="id" column="id">
          <!-- 指定主键的生产方式 -->
          <generator class="native"></generator>
      </id>
      <!-- 普通属性与表的映射关系,名字相同可以写一个 -->
      <property name="name" column="name"></property>
      <property name="sex"></property>
      <property name="birthday" type="date"></property>
  </class>
  
</hibernate-mapping>    

6.创建SessionFactory对象，获取Session对象 通过Session对象以面向对象形式操作关系型数据库

package com.zdsofe.hibernate;

import java.util.Date;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

public class Test {

    public static void main(String[] args) {
      //通过配置文件对象获得配置文件
      Configuration cfg = new Configuration().configure();
      //获取服务注册器对象
      StandardServiceRegistryBuilder ssrb = new StandardServiceRegistryBuilder();
      //获得注册器对象
      ServiceRegistry serviceRegistry = ssrb.applySettings(cfg.getProperties()).build();
      //创建SessionFactory
      SessionFactory sessionFactory = cfg.buildSessionFactory(serviceRegistry);
      //通过session工厂创建session
      Session session = sessionFactory.getCurrentSession();
      //开启事务
      session.beginTransaction();
      //进行数据库操作      
      Student stu = new Student(); //(瞬时状态,随时可能被销毁，被垃圾回收器回收)
      stu.setName("饶鹏");
      stu.setSex("女");
      stu.setBirthday(new Date());
     
      //保存数据
      Integer i = (Integer)session.save(stu);//当stu对象和session关联，并且有个唯一的标识(主键)，那么此时的状态称为持久化
      System.out.println(i);
      stu.setSex("男");//处于持久化状态时会直接修改，不用调用save、update等
      //查询
      /*  Student stu2 = (Student) session.get(Student.class, 4);*/
      //删除
      /* session.delete(stu2);*/   //此时stu属于删除态，不建议使用
      //提交事务
      session.getTransaction().commit();//此时的状态称为脱管状态(此时的session已经销毁)
      
      //重新获取session
      session=sessionFactory.getCurrentSession();
      //开启事务
      session.beginTransaction();
      session.update(stu);//在此与session关联，那么此时的状态称为持久化
      //提交事务
      session.getTransaction().commit();
     
         
    }

}

以编程的方式获得配置文件

package com.zdsofe.hibernate;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

public class Test1 {

    public static void main(String[] args) {
        //以编程的方式获得配置文件
        Configuration cfg=new Configuration();
        cfg.setProperty("hibernate.connection.driver_class","com.mysql.jdbc.Driver" );
        cfg.setProperty("hibernate.connection.url", "jdbc:mysql://localhost:3306/db_hibernate");
        cfg.setProperty("hibernate.connection.username", "root");
        cfg.setProperty("hibernate.connection.password", "775297");
        cfg.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL5Dialect");
        cfg.setProperty("hibernate.current_session_context_class", "thread");
        cfg.addResource("com/zdsofe/hibernate/Student.hbm.xml");
        //获得注册器对象
        ServiceRegistry  serviceRegistry=new StandardServiceRegistryBuilder().applySettings(cfg.getProperties()).build();
        //创建session工厂
        SessionFactory  sessionFactory=cfg.buildSessionFactory(serviceRegistry);
        //创建session
        Session session=sessionFactory.getCurrentSession();
        //开启事务
        session.beginTransaction();
        //提交事务
        session.getTransaction().commit();
        
        
        
    }
}