[mybatis]缓存_一级缓存_一级缓存失效的四种情况

Posted 2022-02-11 唐火

• 1.sqlSession不同

 @Test
    public void test05() throws IOException 
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();

        SqlSession sqlSession01 = sqlSessionFactory.openSession();

        try
        

            EmployeeMapper mapper01 = sqlSession01.getMapper(EmployeeMapper.class);

            Employee emp01 = mapper01.getEmpById(1);

            System.out.println(emp01);

            SqlSession  sqlSession02   =  sqlSessionFactory.openSession();

            EmployeeMapper mapper02 = sqlSession02.getMapper(EmployeeMapper.class);

              Employee emp02 =   mapper02.getEmpById(1);

            System.out.println(emp02);

            System.out.println(emp01==emp02);


            sqlSession02.close();

        finally 

            sqlSession01.close();

        
    

• 2.sqlSession相同，查询条件不同

    @Test
    public void test05() throws IOException 
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();

        SqlSession sqlSession01 = sqlSessionFactory.openSession();

        try
        

            EmployeeMapper mapper01 = sqlSession01.getMapper(EmployeeMapper.class);

            Employee emp01 = mapper01.getEmpById(1);

            System.out.println(emp01);

//            SqlSession  sqlSession02   =  sqlSessionFactory.openSession();
//
//            EmployeeMapper mapper02 = sqlSession02.getMapper(EmployeeMapper.class);

              Employee emp02 =   mapper01.getEmpById(2);

            System.out.println(emp02);

            System.out.println(emp01==emp02);


//            sqlSession02.close();

        finally 

            sqlSession01.close();

        
    

• 3.sqlSession相同，两次查询之间执行了增删改操作（这次增删改可能对当前数据有影响）

 @Test
    public void test05() throws IOException 
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();

        SqlSession sqlSession01 = sqlSessionFactory.openSession();

        try
        

            EmployeeMapper mapper01 = sqlSession01.getMapper(EmployeeMapper.class);

            Employee emp01 = mapper01.getEmpById(1);

            System.out.println(emp01);

//            SqlSession  sqlSession02   =  sqlSessionFactory.openSession();
//
//            EmployeeMapper mapper02 = sqlSession02.getMapper(EmployeeMapper.class);

            mapper01.addEmp(new Employee(null,"testCache","cache","1"));

            System.out.println("数据添加成功");

              Employee emp02 =   mapper01.getEmpById(2);

            System.out.println(emp02);

            System.out.println(emp01==emp02);


//            sqlSession02.close();

        finally 

            sqlSession01.close();

        
    

• 4.sqlSession相同，手动清除了一级缓存（缓存清空）

    @Test
    public void test05() throws IOException 
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();

        SqlSession sqlSession01 = sqlSessionFactory.openSession();

        try
        

            EmployeeMapper mapper01 = sqlSession01.getMapper(EmployeeMapper.class);

            Employee emp01 = mapper01.getEmpById(1);

            System.out.println(emp01);

//            SqlSession  sqlSession02   =  sqlSessionFactory.openSession();
//
//            EmployeeMapper mapper02 = sqlSession02.getMapper(EmployeeMapper.class);

//            mapper01.addEmp(new Employee(null,"testCache","cache","1"));

            System.out.println("数据添加成功");

            sqlSession01.clearCache();

              Employee emp02 =   mapper01.getEmpById(2);

            System.out.println(emp02);

            System.out.println(emp01==emp02);


//            sqlSession02.close();

        finally 

            sqlSession01.close();