Hibernate getCurrentSession()和openSession()的区别

1. 通过getCurrentSession()创建的Session会绑定到当前线程上；openSession()不会。
2. 通过getCurrentSession()获取Session，首先是从当前上下文中寻找旧的Session,如果没有，则创建新的Session；而openSession()是每次都创建新的Session。
3. getCurrentSession()创建的Session在事物提交时自动关闭；openSession()创建的Session需要手动关闭。

        @Test
        public void testTeacherSave() {
   
            Teacher t = new Teacher();
   
            t.setName("t1");
            t.setTitle("middle");
            t.setBirthDate(new Date());
   
            Session session = sessionFactory.openSession();
            //Session session = sessionFactory.getCurrentSession();
   
            session.beginTransaction();
            session.save(t);
   
            Session session2 = sessionFactory.getCurrentSession();
   
            System.out.println(session == session2);
   
            session.getTransaction().commit();
   
            Session session3 = sessionFactory.getCurrentSession();
   
            System.out.println(session == session3);
   
        }
   

   输出：Hibernate:
       insert
       into
           Teacher
           (birthDate, gender, good, name, title)
       values
           (?, ?, ?, ?, ?)
   false
   false

    @Test
        public void testTeacherSave() {
   
            Teacher t = new Teacher();
   
            t.setName("t1");
            t.setTitle("middle");
            t.setBirthDate(new Date());
   
            //Session session = sessionFactory.openSession();
            Session session = sessionFactory.getCurrentSession();
   
            session.beginTransaction();
            session.save(t);
   
            Session session2 = sessionFactory.getCurrentSession();
   
            System.out.println(session == session2);
   
            session.getTransaction().commit();
   
            Session session3 = sessionFactory.getCurrentSession();
   
            System.out.println(session == session3);
   
        }

   输出：Hibernate:
       insert
       into
           Teacher
           (birthDate, gender, good, name, title)
       values
           (?, ?, ?, ?, ?)
   true
   false