【hibernate进阶】hibernate搭建开发环境+实例讲解

本篇博客将带着大家以一个简单的实例来学习hibernate项目。

1、创建java项目

2、创建User Library，加入依赖包

* 加入数据库驱动（mysql驱动）

具体的操作步骤参考我的上一篇博客：【hibernate进阶】如何在myeclipse中添加jar包

3、提供hibernate.cfg.xml文件，完成基本的配置

<strong><span style="font-size:18px;"><!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.url">jdbc:mysql://localhost:3306/hibernate_first</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">123</property>
        <!-- mysql language adatper，if you want to change database ,you juse need to change there  -->
        <!-- <property name="hibernate.connection.dialect">org.hibernate.dialect.MySQLDialect</property> -->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="hibernate.show_sql">true</property>
        <!--  <property name="hibernate.format_sql">true</property>-->

        <mapping resource="com/bjpowernode/hibernate/User.hbm.xml"/>
    </session-factory>
</hibernate-configuration></span></strong>

4、建立实体类User.java

<strong><span style="font-size:18px;"><strong><span style="font-size:18px;">package com.bjpowernode.hibernate;

import java.util.Date;

public class User {

	private String id;

	private String name;

	private String password;

	private Date createTime ;

	private Date expireTime;

	public String getId() {
		return id;
	}

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

	public String getName() {
		return name;
	}

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

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public Date getCreateTime() {
		return createTime;
	}

	public void setCreateTime(Date createTime) {
		this.createTime = createTime;
	}

	public Date getExpireTime() {
		return expireTime;
	}

	public void setExpireTime(Date expireTime) {
		this.expireTime = expireTime;
	}

}</span></strong>
</span></strong>

5、提供User.hbm.xml文件，完成实体类的映射

<strong><span style="font-size:18px;"><?xml version="1.0"?>
<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping >
	<class name="com.bjpowernode.hibernate.User">
		<id name="id">
			<generator class="uuid"/>
		</id>
		<property name="name"/>
		<property name="password"/>
		<property name="createTime"/>
		<property name="expireTime"/>
	</class>
</hibernate-mapping></span></strong>

6、将User.hbm.xml文件加入到hibernate.cfg.xml文件中

这个在3步的时候已经加进去了

7、编写工具类ExoprtDB.java,将hbm生成ddl，也就是hbm2ddl

<strong><span style="font-size:18px;">package com.bjpowernode.hibernate;

import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;

/**
 * hbm  Generation ddl
 * @author CXC
 *
 */
public class ExoprtDB {

	public static void main(String[] args){
		//Read by default hibernate.cfg.xml File
		Configuration cfg=new Configuration().configure();

		SchemaExport export=new SchemaExport(cfg);

		export.create(true, true);
	}

}</span></strong>

在这一步的时候，就可以生成user表了，run as java application ，查看数据库，就可以生成user表了。

8、建立客户端类Client，添加用户数据到mysql

<strong><span style="font-size:18px;">package com.bjpowernode.hibernate;

import java.text.SimpleDateFormat;
import java.util.Date;

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

public class Client {

	public static void main(String[] args) {

		//read hibernate.cfg.xml file
		Configuration  cfg=new Configuration().configure();

		//sessionfactory thread safe
		//build sessionfactory
		SessionFactory factory=cfg.buildSessionFactory();

		//acquire session
		Session session=null;
		try{

			session=factory.openSession();
			//open Transaction
			session.beginTransaction();
			User user=new User();
			user.setName("12");
			user.setPassword("123");
			/*  user.setCreateTime(new Date());
	 			user.setExpireTime(new Date());*/

			Date date=new Date();
            SimpleDateFormat temp=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
             String date2=temp.format(date);
             Date date3=temp.parse(date2);  

             user.setCreateTime(date3);
 			user.setExpireTime(date3);

			//save User object
			session.save(user);

			//commit Transaction
			session.getTransaction().commit();

		}catch(Exception e){
			e.printStackTrace();
			//rollback  Transaction
			session.getTransaction().rollback();

		}finally{
			if(session !=null){
				if(session.isOpen()){
					//close session
					session.close();

				}

			}

		}

	}

}
</span></strong>

在console中，输入的insert into user(.....)信息表示将数据插入到数据库中了。

通过navicat，查看插入的数据

这样，hibernate的项目就完成了。

遇到的问题：

在插入的时候，遇到了日期插不进去的问题。以为是mysql引用的jar包问题，重新引用了没有解决，想到了在之前也遇到过类似的问题，把转了一下日期的格式就解决了。