[mybatis]缓存_二级缓存使用&细节

Posted 2022-02-12 唐火

二级缓存

开启全局二级缓存

 <setting name="cacheEnabled" value="true"/>

去mapper.xml中配置使用二级缓存

<cache></cache>

<cache eviction="FIFO" flushInterval="60000" readOnly="false" size="1024" ></cache>

• cache中的配置

• type = “”：指定自定义缓存的全类名；实现Cache接口即可；

我们的POJO需要实现序列化接口

测试

@Test
    public void testSecondLevelCache() throws IOException 
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();

        SqlSession sqlSession = sqlSessionFactory.openSession();
         SqlSession sqlSession1 =   sqlSessionFactory.openSession();

        try
        

            EmployeeMapper mapper = sqlSession.getMapper(EmployeeMapper.class);

            EmployeeMapper mapper1 = sqlSession1.getMapper(EmployeeMapper.class);

            Employee emp01 = mapper.getEmpById(1);

            System.out.println(emp01);

            sqlSession.close();

            Employee emp02 = mapper1.getEmpById(1);

            System.out.println(emp02);

            sqlSession1.close();

        finally 

            sqlSession.close();

        
    

• 二级缓存失效

只有会话提交或者关闭以后，一级缓存中的数据才会转移到二级缓存中

  @Test
    public void testSecondLevelCache() throws IOException 
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();

        SqlSession sqlSession = sqlSessionFactory.openSession();
         SqlSession sqlSession1 =   sqlSessionFactory.openSession();

        try
        

            EmployeeMapper mapper = sqlSession.getMapper(EmployeeMapper.class);

            EmployeeMapper mapper1 = sqlSession1.getMapper(EmployeeMapper.class);

            Employee emp01 = mapper.getEmpById(1);

            System.out.println(emp01);



            Employee emp02 = mapper1.getEmpById(1);

            System.out.println(emp02);

            sqlSession.close();
            sqlSession1.close();

        finally