1：首先，设计好框架：

2：写工具类：

package com.ftz.Demo.utils;

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;

public class MybatisUtil {

    private static SqlSessionFactory sqlSessionFactory;
    static {
        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new  SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    public static SqlSession getSqlSession(){

        return sqlSessionFactory.openSession();

    }

}

3：配置文件：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url"
                          value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&amp;characterEncoding=utf8&amp;serverTimezone=GMT%2B8&amp;useSSL=false"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/ftz/Demo/dao/userMapper.xml"/>
    </mappers>
</configuration>

4：写实体类：

package com.ftz.Demo.po;

import lombok.Data;

@Data
public class User {

    private int id; //id
    private String name; //姓名
    private String pwd; //密码

}

5：写接口：

package com.ftz.Demo.dao;

import com.ftz.Demo.po.User;

import java.util.List;

public interface UserMapper {
    List<User> getUserList();
}

6：写Mapper.xml：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ftz.Demo.dao.UserMapper">
    <select id="getUserList" resultType="com.ftz.Demo.po.User">
        select * from mybatis.user
    </select>
</mapper>

7：测试：

package com.ftz.Demo.dao;

import com.ftz.Demo.po.User;
import com.ftz.Demo.utils.MybatisUtil;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.List;

public class UserDaoTest {
    @Test
    public void test() {

       SqlSession sqlSession =  MybatisUtil.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> userList = mapper.getUserList();

        for (User user : userList) {
            System.out.println(user);
        }
        sqlSession.close();
    }
}

注意：配置文件的过滤：在pom里面写：

<build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
                <filtering>true</filtering>
            </resource>

            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>