初识hibernate

谁借莪１个温暖的怀抱￠ 2022-05-17 04:29 167阅读 0赞

*  hibernate版本：5.0.7

1.  要使用hibernate,首先下载hibernate,然后导入../lib/required下面的jar包，这个文件夹里的jar包都是必须要的jar包，如果要使用其他的，比如c3p0,就导入optional中有的c3p0jar包即可。
2.  配置好两个配置文件,建立一个类Customer,数据库有张表cst\_customer,类中的属性与表中字段对应(ORM)，再引入日志文

件(log4j.properties),里面可以配置相关信息。

映射文件(类名.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>
        	
        	<class name="hibernate_demo01.Customer" table="cst_customer" catalog="hibernate_day01">
        		
        		
        		<id name="cust_id" column="cust_id">
                    
        			<generator class="native"/>
        		</id>
        		
        		
        		<property name="cust_name" column="cust_name" length="32" />
    			<property name="cust_source" column="cust_source" length="32"/>
    			<property name="cust_industry" column="cust_industry"/>
    			<property name="cust_level" column="cust_level"/>
    			<property name="cust_phone" column="cust_phone"/>
    			<property name="cust_mobile" column="cust_mobile"/>
        	</class>
        </hibernate-mapping>

核心配置文件(hibernate.cfg.xml)：

<?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>
     
     			
    			<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    			<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate_day01?useSSL=true&useUnicode=true&characterEncoding=UTF-8</property>
    			<property name="hibernate.connection.username">root</property>
    			<property name="hibernate.connection.password">root</property>
    			<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    		 
    			
    			<property name="hibernate.show_sql">true</property>
    			<property name="hibernate.format_sql">true</property>
    			
    			<property name="hibernate.hbm2ddl.auto"></property>			
    			
    			
    			<mapping resource="hibernate_demo01/Customer.hbm.xml"/>
     
    		</session-factory>
    	</hibernate-configuration>

3.第一个小案例

package hibernate_demo01;
    
    import org.hibernate.Session;
    
    import org.hibernate.SessionFactory;
    import org.hibernate.Transaction;
    import org.hibernate.cfg.Configuration;
     
    
    /**
     * hibernate入门案例
     * @author LSD
     *
     */
    public class HibernateDemo01 {
    
    
    	public static void main(String[] args) {
    		//1.加载核心配置文件
    		Configuration configuration = new Configuration().configure();
    		
    		//如果将hibernate.cfg.xml替换为hibernate.properties (hibernate.properties中无法配置映射文件)
    		//那么第一步就是：Configuration configuration = new Configuration();
    		//configuration.addResource("hibernate_demo01/Customer.hbm.xml");
    		
    		//2.创建一个SessionFactory,类似JDBC中连接池
    		SessionFactory sessionFactory = configuration.buildSessionFactory();
    
    		//3.通过SessionFactory获取Session对象，类似JDBC中Connection
    		Session session = sessionFactory.openSession();
    		
    		//4.手动开启事务
    		Transaction transaction = session.beginTransaction();
    		
    		//5.编写代码
    		
    		Customer customer = new Customer();
    		customer.setCust_name("某东");
    		session.save(customer);
    		
    		//6.事务提交
    		transaction.commit();
    			
    	}
    }