Mybatis中dao层实现

在上一个笔记中继续：

　　因为要基于dao层，那么我们只需要又一个dao的接口，和一个mapper的文件就可以测试了。

　　但是基于dao层的时候需要规范：

　　　　Mapper.xml文件中的namespace与mapper接口的全限定名相同
　　　　Mapper接口方法名和Mapper.xml中定义的每个statement的id相同
　　　　Mapper接口方法的输入参数类型和mapper.xml中定义的每个sql的parameterType的类型相同
　　　　Mapper接口方法的输出参数类型和mapper.xml中定义的每个sql的resultType的类型相同

　　这四种规范其实就是这个意思：

　　　　

然后测试：

　　

@Test
    public void testProxyDao() throws IOException {
        InputStream resourceAsStream = Resources.getResourceAsStream("SqlMapperConfig.xml");
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        //获得MyBatis框架生成的UserMapper接口的实现类
        User user = userMapper.findById(1);
        System.out.println(user);
        sqlSession.close();
    }

结果输出；

...............
Sat Jul 13 16:43:39 CST 2019 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
User{id=1, username='zhangsan ', password='123456'}

Process finished with exit code 0