Mybatis基础：注解开发，面向接口（引出三个面向的区别）

public interface UserMapper {

    @Select("select * from user")
    List<User> getUsers();

}

    <mappers>
        <mapper class="com.king.dao.UserMapper"/>
    </mappers>

    @Test
    public void mapperTest(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> userList = mapper.getUsers();
        for (User user : userList) {
            System.out.println(user);
        }
        sqlSession.close();
    }