【hibernate进阶】hibernate搭建开发环境+实例讲解

清疚 2022-07-24 06:10 226阅读 0赞

**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  
\* HIBERNATE\_HOME/lib/\*.jar  
\* HIBERNATE\_HOME/hibernate3.jar**

**\* 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][hibernate_myeclipse_jar]**

**3、提供hibernate.cfg.xml文件，完成基本的配置**

<!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>
 
 
 <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
 <property name="hibernate.show_sql">true</property>
 
 
 <mapping resource="com/bjpowernode/hibernate/User.hbm.xml"/>
 </session-factory>
 </hibernate-configuration>

**4、建立实体类User.java**

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;
 	}
 	
 	
 
 }

**5、提供User.hbm.xml文件，完成实体类的映射**

<?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>

**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**

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);
 	}
 
 }

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。

**![Center][]**

**8、建立客户端类Client，添加用户数据到mysql**

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();
 					
 				}
 				
 			}
 			
 		}
 		
 		
 		
 
 	}
 
 }

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

**![Center 1][]**

**通过navicat，查看插入的数据**

**![Center 2][]**

**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。**

**![Center 3][]**

[hibernate_myeclipse_jar]: http://blog.csdn.net/chenxiaochan/article/details/51417369
[Center]: /images/20220722/c08af6a0481d40899c4ea297e47058d6.png
[Center 1]: /images/20220722/7481c619c0744b87aab7828400960084.png
[Center 2]: /images/20220722/e68fc6aec431412abf20dba08eaff205.png
[Center 3]: /images/20220722/e5612414300d429e83668461cd0a08a2.png