一个简单的Hibernate工具类HibernateUtil

 1 package com.wj.app.util;
 2 
 3 import org.hibernate.Session;
 4 import org.hibernate.SessionFactory;
 5 import org.hibernate.cfg.Configuration;
 6 import org.hibernate.service.ServiceRegistry;
 7 import org.hibernate.service.ServiceRegistryBuilder;
 8 
 9 public class HibernateUtil {
10     public static final SessionFactory sessionFactory;
11     //ThreadLocal可以隔离多个线程的数据共享，因此不需要对线程进行同步
12     public static ThreadLocal<Session> session = new ThreadLocal<Session>();
13     static
14     {
15         //使用默认配置文件创建Configuration实例
16         Configuration cfg = new Configuration()
17                                  .configure();
18  
19         //以Configuration实例来创建SessionFactory实例
20         ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
21                                                .applySettings(cfg.getProperties())
22                                                .buildServiceRegistry();
23         
24         /*ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
25         .applySettings(cfg.getProperties()).build();*/
26         
27         sessionFactory = cfg.buildSessionFactory(serviceRegistry);
28     }
29     public static Session currentSession() {
30         
31         Session s = session.get();
32         //如果该线程还没有Session，则创建一个新的Session
33         if (s == null) 
34         {
35             s = sessionFactory.openSession();
36             //将获得的Session变量存储在ThreadLocal变量session里
37             session.set(s);
38         }
39         return s;
40     }
41     
42     public static void clossSession() {
43         Session s = session.get();
44         if (s != null) 
45         {
46             s.close();            
47         }
48         session.set(null);
49     }
50 }