code: public static void closeSqlSession() {
          SqlSession sqlSession = tl_sqlSession.get();
          if (sqlSession != null) {
              //关闭SqlSession对象
              sqlSession.close();
              //与当前线程解绑
              tl_sqlSession.remove();
          }
  
      }
docs: 关闭SqlSession对象，并与当前线程解除绑定,若当前线程中没有SqlSession对象则不执行任何操作