Hibernate中的getCurrentSession和openSession

	@Test
	public void T1() {
		Teacher t = new Teacher();
		t.setGender(Gender.femal);
		t.setName("abc");
		t.setId(2);
		t.setGood(true);
		
		Session session,session2;
		/**
		 * getCurrentSession,如果当前上下文环境中有Session,
		 * 则无须创建就会拿当前环境的Session,当commit时会自动
		 * close
		 */
		session = sf.getCurrentSession();//无须session.close();
		/**
		 * openSession用于是打开新的Session
		 * 需要用session.close();
		 */
		//Session session = sf.openSession();
		session.beginTransaction();
		session.save(t);
		session2 = sf.getCurrentSession();
		
		System.out.println(session == session2);//true
		/**
		 * 将会导致第一个Session消失,
		 * 再次获取将导致新的Session产生
		 */
		session.getTransaction().commit();//
		
		Session session3 = sf.getCurrentSession();
		System.out.println(session2 == session3);//false
	}