junit报错，请老师解答，急！！

package com.java.jdbc;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import org.junit.Test;

public class JDBCDemo1 {

@Test

/**

* JDBC的入门程序

*/

public void demo1() {

Connection conn = null;

Statement stmt = null;

ResultSet rt = null;

try {

//1.加载驱动

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

//2.获得连接

conn = DriverManager.getConnection(

"jdbc:mysql://127.0.0.1:3306/jdbctest"+

"?useSSL=false&serverTimezone=Hongkong&useUnicode=true&characterEncoding=utf-8",

"root","liubin");

//3.创建执行SQL语句的对象，并执行SQL

//3.1创建执行SQL的对象

String sql = "select * from user";

stmt = conn.createStatement();

//3.2执行sql

rt = stmt.executeQuery(sql);

while(rt.next()) {

int  id = rt.getInt("id");

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

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

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

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

}

//4.释放资源

rt.close();

stmt.close();

conn.close();

} catch (ClassNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

手动添加了辅助材料给的junit-4.11.jar包也试了，也是报错，怎么解决很急，请老师速回！！