SqlSessionFactory sqlSessionFactory = null;
@BeforeEach
public void before() throws IOException{
      String resource = "mybatis-config.xml";
      InputStream inputStream = Resources.getResourceAsStream(resource);
      //这个sqlFactory是核心,相关数据全围绕这个sqlsessionFactory进行
      SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
      sqlSessionFactory = sqlSessionFactoryBuilder.build(inputStream);
    }

@Before失效了,使用@BeforeEach替代即可生效