Mybatis使用配置（2mapper代理）

目的：解决硬编码问题，更友好的调用封装好sql语句的接口方法
例：原生方法selectList()执行sql，还需要硬编码test.selectAll
List users = sqlSession.selectList(“test.selectAll”);

    
        select *
        from tb_user;
    

package com.niujl.mapper;

import com.niujl.pojo.User;

import java.util.List;

public interface UserMapper {


    List selectAll();

}

package com.niujl;

import com.niujl.mapper.UserMapper;
import com.niujl.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class MyBatisDemo2 {
    public static void main(String[] args) throws IOException {
        //1、加载核心配置文件
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//        2、获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
//        3、执行sql
//        List users = sqlSession.selectList("test.selectAll");
//        System.out.println(users);
//        3、1获取UserMapper接口代理的对象
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        List users = userMapper.selectAll();
        System.out.println(users);
//        4、释放资源
        sqlSession.close();
    }
}