Hibernate框架入门

CREATE TABLE `user` (
`uid` bigint(32) NOT NULL AUTO_INCREMENT,
`uname` varchar(32) NOT NULL,
PRIMARY KEY (`uid`)
)

 1 package domain;
 2 public class User {
 3     private Long uid;
 4     private String uname;
 5     
 6     public Long getUid() {
 7         return uid;
 8     }
 9     public void setUid(Long uid) {
10         this.uid = uid;
11     }
12     public String getUname() {
13         return uname;
14     }
15     public void setUname(String uname) {
16         this.uname = uname;
17     }
18     @Override
19     public String toString() {
20         return "User [uid=" + uid + ", uname=" + uname + "]";
21     }
22 }

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC 
 3     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4     "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 5     
 6     <hibernate-mapping package="domain" >
 7 
 8     <class name="User" table="user" >
 9         <id name="uid"  >
10             <generator class="native"></generator>
11         </id>
12         
13     <property name="uname" column="uname" ></property>
14     </class>
15 </hibernate-mapping>

<?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>
        <!-- 
        #hibernate.dialect org.hibernate.dialect.MySQLDialect
        #hibernate.dialect org.hibernate.dialect.MySQLInnoDBDialect
        #hibernate.dialect org.hibernate.dialect.MySQLMyISAMDialect
        #hibernate.connection.driver_class com.mysql.jdbc.Driver
        #hibernate.connection.url jdbc:mysql:///test
        #hibernate.connection.username gavin
        #hibernate.connection.password
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql:///hibernate</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">password</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">update</property>

        <mapping resource="domain/User.hbm.xml" />
        
    </session-factory>
</hibernate-configuration>

 1 package test;
 2 
 3 import org.hibernate.Session;
 4 import org.hibernate.SessionFactory;
 5 import org.hibernate.Transaction;
 6 import org.hibernate.cfg.Configuration;
 7 import org.junit.Test;
 8 
 9 import domain.User;
10 
11 public class Demo {
12     
13     @Test
14     //使用hibernate框架，通过操作User对象往user表中插入一条数据。
15     public void addUser(){
16         //操作涉及的核心类
17         Configuration config = new Configuration().configure();
18         SessionFactory factory = config.buildSessionFactory();
19         Session session = factory.openSession();
20         Transaction tx = session.beginTransaction();
21         
22         //操作User
23         //-----------------------
24         User user = new User();
25         user.setUid(1l);
26         user.setUname("张三");
27         
28         session.save(user);//执行
29         //-----------------------
30         
31         //关闭资源
32         tx.commit();
33         session.close();
34         factory.close();
35     }

 1 //1 创建,调用空参构造
 2 Configuration conf = new Configuration().configure();
 3 //2 根据配置信息,创建 SessionFactory对象
 4 SessionFactory sf = conf.buildSessionFactory();
 5 //3 获得session
 6 Session session = sf.openSession();
 7 //4 session获得操作事务的Transaction对象
 8 //获得操作事务的tx对象
 9 Transaction tx = session.getTransaction();
10 tx.begin();
11 //开启事务并获得操作事务的tx对象(建议使用)
12 Transaction tx2 = session.beginTransaction();
13 //----------------------------------------------
14 //1 获得要修改的对象
15User u = session.get(User.class, 1l);
16 //2 调用delete删除对象
17 session.delete(u);
18 //----------------------------------------------
19 tx2.commit();//提交事务
20 session.close();//释放资源
21 sf.close();//释放资源

 1 package utils;
 2 
 3 import org.hibernate.HibernateException;
 4 import org.hibernate.Session;
 5 import org.hibernate.SessionFactory;
 6 import org.hibernate.cfg.Configuration;
 7 
 8 public class HibernateUtils {
 9 
10     // 会话工厂，以单例方式管理
11     private static SessionFactory sessionFactory;
12 
13     // ThreadLocal存储session
14     private static ThreadLocal<Session> session = new ThreadLocal<Session>();
15 
16     // 以单例方式管理sessionFactory
17     static {
18         try {
19             sessionFactory = new Configuration().configure("hibernate.cfg.xml").buildSessionFactory();
20         } catch (HibernateException e) {
21             e.printStackTrace();
22             throw new HibernateException("初始化会话工厂失败！");
23         }
24 
25     }
26     //得到一个单例的会话工厂
27     public static SessionFactory getSessionFactory(){
28         return sessionFactory;
29     }
30     //获取一个新session
31     public static Session openSession(){
32         return sessionFactory.openSession();
33     }
34  
35     public static Session getCurrentSession() throws HibernateException {
36         return sessionFactory.getCurrentSession(); 
37     }
38 
39     public static void closeSession() throws HibernateException {
40         sessionFactory.getCurrentSession().close();
41     }
42 
43 }