Hibernate源码解析

Hibernate源码解析

一、先在官网 https://sourceforge.net/projects/hibernate/ 下载最新版本的开发包

下载解压后

• documentation存放Hibernate的相关文件与API
• lib存放Hibernate编译和运行所依赖的jar包，其中required子目录下包含了运行Hibernate项目必须的jar包。
• project存放Hibernate各种相关的源代码与资源，project目录下的etc目录非常重要，它里面有一些关于Hibernate的配置信息。

二、新建一个 Java Project 即可

三、导入项目所需的jar包

四、配置Hibernate4框架各个层

创建数据库和表

CREATE DATABASE hibernate;
USE hibernate;

DROP TABLE IF EXISTS `t_class`;
CREATE TABLE `t_class` (
  `classId` bigint(20) NOT NULL AUTO_INCREMENT,
  `className` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`classId`)
) ENGINE=InnoDB AUTO_INCREMENT=16 DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS `t_student`;
CREATE TABLE `t_student` (
  `stuId` bigint(20) NOT NULL AUTO_INCREMENT,
  `stuName` varchar(255) DEFAULT NULL,
  `classId` bigint(20) DEFAULT NULL,
  PRIMARY KEY (`stuId`),
  KEY `FK_frxpowmeqnmf3sflhwgq3x0ub` (`classId`),
  CONSTRAINT `FK_frxpowmeqnmf3sflhwgq3x0ub` FOREIGN KEY (`classId`) REFERENCES `t_class` (`classId`)
) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=utf8;

项目结构

Hibernate4相关配置文件

• hibernate.cfg.xml：它是Hibernate框架的核心配置文件。放在src目录下
• xxx.hbm.xml：它主要是用于描述类与数据库中的表的映射关系。放在 hsx.com.model 目录下

hibernate.cfg.xml

    

        
        com.mysql.jdbc.Driver
        jdbc:mysql://localhost:3306/hibernate //hibernate为数据库名
        root
        123456  //数据库密码
       
        
        org.hibernate.dialect.MySQL5Dialect
	
        
        true

        
        update
        
     	
        
        
          
        
    

Student.hbm.xml

创建实体类
hsx.com.model.Student.java

package hsx.com.model;

public class Student {

	private long id;
	private String name;
	private Class c;

	public long getId() {
		return id;
	}

	public void setId(long id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public Class getC() {
		return c;
	}

	public void setC(Class c) {
		this.c = c;
	}

	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name + "]";
	}

}

生成Session工厂
hsx.com.util.HibernateUtil.java

package hsx.com.util;

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

public class HibernateUtil {

	private static final SessionFactory sessionFactory = buildSessionFactory();

	private static SessionFactory buildSessionFactory() {
		/* 实例化配置文件 */
		Configuration configuration = new Configuration().configure();
		/* 实例化服务登记 */
		ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
				.applySettings(configuration.getProperties()).build();
		/* 获取Session工厂 */
		return configuration.buildSessionFactory(serviceRegistry);
	}

	public static SessionFactory getSessionFactory() {
		return sessionFactory;
	}

}

创建测试类
hsx.com.service.StudentTest.java

package hsx.com.service;

import java.util.List;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import hsx.com.model.Student;
import hsx.com.util.HibernateUtil;

/*XML版CRUD实现*/
public class StudentTest {

	private SessionFactory sessionFactory = HibernateUtil.getSessionFactory();

	public static void main(String[] args) {
		StudentTest studentTest = new StudentTest();
		studentTest.add();
		// studentTest.delete();
		// studentTest.update();
		// studentTest.getAllStudent();
	}

	private void add() {
		/* 生成一个session */
		Session session = sessionFactory.openSession();
		/* 开启事务 */
		session.beginTransaction();

		Student s = new Student();
		s.setName("周杰伦");
		session.save(s);

		/* 提交事务 */
		session.getTransaction().commit();
		/* 关闭session */
		session.close();
	}

	private void delete() {
		/* 生成一个session */
		Session session = sessionFactory.openSession();
		/* 开启事务 */
		session.beginTransaction();

		Student student = (Student) session.get(Student.class, Long.valueOf(1));
		session.delete(student);

		/* 提交事务 */
		session.getTransaction().commit();
		/* 关闭session */
		session.close();
	}

	private void update() {
		/* 生成一个session */
		Session session = sessionFactory.openSession();
		/* 开启事务 */
		session.beginTransaction();

		Student student = (Student) session.get(Student.class, Long.valueOf(2));
		student.setName("张三2");
		session.save(student);

		/* 提交事务 */
		session.getTransaction().commit();
		/* 关闭session */
		session.close();
	}

	private void getAllStudent() {
		/* 生成一个session */
		Session session = sessionFactory.openSession();
		/* 开启事务 */
		session.beginTransaction();

		String hql = "from Student";
		Query query = session.createQuery(hql);
		@SuppressWarnings("unchecked")
		List studentList = query.list();
		for (Student student : studentList) {
			System.out.println(student);
		}

		/* 提交事务 */
		session.getTransaction().commit();
		/* 关闭session */
		session.close();
	}

}