关于注册驱动的问题

我注释了注册驱动的代码，为何还能正常执行，下面是执行的代码

package com.imooc.jdbc.demo1;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

//import java.sql.SQLException;

import java.sql.Statement;

import org.junit.Test;

//import com.mysql.cj.jdbc.Driver;

public class JDBCDemo1 {

@Test

/**

* JDBC的入门程序

*/

public void demo1(){

try {

//Class.forName("com.mysql.cj.jdbc.Driver");

//OR

//new com.mysql.cj.jdbc.Driver();

Connection conn = DriverManager.getConnection("jdbc:mysql:///jdbctest?useSSL=false&serverTimezone=Hongkong&useUnicode=true&characterEncoding=utf-8", "root", "123456");

String sql = "select * from user";

Statement stmt = conn.createStatement();

ResultSet resultSet = stmt.executeQuery(sql);

while (resultSet.next()) {

int uid = resultSet.getInt("uid");

String username = resultSet.getString("username");

String password = resultSet.getString("password");

String name = resultSet.getString("name");

System.out.println(uid+"  "+username+"  "+password+"  "+name);

}

resultSet.close();

stmt.close();

conn.close();

} catch (Exception e) {

// TODO 自动生成的 catch 块

e.printStackTrace();

}

}

}