创建SqlSession执行sql语句

package org.example;//注意这个包
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 org.example.chentianyu.Student;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
public class MyApp {
    public static void main(String[] args) throws IOException {
        //访问mybatis读取student数据
        //1.定义主配置文件的名称,从类路径(target/classes)
        String config = "mybatis.xml";
        //2.读取这个config表示的文件
        // org.apache.ibatis.io提供的,这个是mybatis官方提供的
        InputStream in = Resources.getResourceAsStream(config);
        //3.创建SqlSessionFactoryBuilder对象
        SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
        //4.创建SqlSessionFactory对象
        SqlSessionFactory factory = builder.build(in);
        //5.(重要)获取SqlSession对象,从SqlSessionFactory中获取
        SqlSession sqlSession = factory.openSession();
        //6.(重要)指定要执行的sql语句的标识。sql映射文件中的namespace + "." + 标签的id值
        String sqlId = "org.example.dao.StudentDao" + "." + "selectStudents";
        //7.执行sql语句。通过sqlId找到sql语句
        List<Student> studentList = sqlSession.selectList(sqlId);
        //8.输出结果
        studentList.forEach(stu -> System.out.println(stu));
        //9.关闭SqlSeesion对象
        sqlSession.close();
    }
}