小米 12 系列正式官宣:新品釋出會定檔 12 月 28 日,蘇炳添代言
阿新 • • 發佈:2021-12-22
MyBatis快取
(1)一級快取
- 1.查詢兩次相同的資料
測試:
@Test public void test(){ SqlSession sqlSession = MybatisUtils.getSqlSession(); UserMapper mapper = sqlSession.getMapper(UserMapper.class); User user = mapper.getUserById(2); System.out.println(user); System.out.println("==============================="); User user2=mapper.getUserById(2); System.out.println(user2); sqlSession.close(); } }
日誌分析:
- 2.快取失效的情況
增刪改操作可能會改變原理啊的資料,所以增刪改之後會重新整理資料
- 3.手動清理快取
@Test public void test(){ SqlSession sqlSession = MybatisUtils.getSqlSession(); UserMapper mapper = sqlSession.getMapper(UserMapper.class); User user = mapper.getUserById(2); System.out.println(user); sqlSession.clearCache();//手動清理快取 User user2=mapper.getUserById(2); System.out.println(user2); sqlSession.close(); }
(2)二級快取
- 步驟:
- 測試:
- 報錯:
- 一些序列化的解釋: