SqlSession sqlSession = MyBatisUtilgetSqlSession; UserDao mapper = sqlSessiongetMapperUserDaoclass; return mappergetUsers;这段代码有什么问题 是否需要关闭Session

这段代码的问题是没有关闭SqlSession。在使用完SqlSession后，应该调用其close()方法进行关闭。正确的写法应该是：

SqlSession sqlSession = MyBatisUtil.getSqlSession();
UserDao mapper = sqlSession.getMapper(UserDao.class);
List<User> users = mapper.getUsers();
sqlSession.close();
return users;

或者使用try-with-resources语句块，自动关闭SqlSession：

try (SqlSession sqlSession = MyBatisUtil.getSqlSession()) {
    UserDao mapper = sqlSession.getMapper(UserDao.class);
    List<User> users = mapper.getUsers();
    return users;
}