创建单例模式

package cn.hrbust.dao;

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

public class HibernateUtils {

    private static Configuration cfg = null;
    private static SessionFactory sf = null;
    static {

        try {
            cfg = new Configuration().configure();//读取配置文件
            sf = cfg.buildSessionFactory();// 创建SessionFactory
        } catch (HibernateException e) {
            e.printStackTrace();
        }
    }

    public static SessionFactory getSessionFactory(){
        return sf;
    }

    public static void close() {
        sf.close();
    }
}

　　保存

@Test
    public void testSavaUser() {
        Configuration cfg = null;
        SessionFactory sf = null;
        Session session = null;
        Transaction ts = null;
        User u = new User();
        u.setName("陈陈");
        u.setGender("男");
        u.setAge(23);
        u.setBirthday(Date.valueOf("1998-12-18"));
        try {
            sf = HibernateUtils.getSessionFactory();
            session = sf.getCurrentSession();
            ts = session.beginTransaction();
            session.save(u);
            ts.commit();
        } catch (HibernateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            if(ts != null) {
                ts.rollback();
            }
        }
    }

　　运行结果

 

查询

@Test
    public void testQueryUser() {
        SessionFactory sf=null;
        Session session =null;
        Transaction ts=null;

        try {
            sf=HibernateUtils.getSessionFactory();//SessionFactory单态模式
            session =sf.getCurrentSession(); //保证每个读写线程有唯一的session实例
            ts=session.beginTransaction();
            Query query=session.createQuery("from User");//类名
            List<User> users =query.list();
            for(User u:users) {
                System.out.println(u.getName()+"  "+u.getGender()+"  "+u.getAge()+"  "+u.getBirthday());
            }

            ts.commit();
        } catch (HibernateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            if(ts!=null) {
                ts.rollback();
            }
        }
    }

　　运行结果