java最新版本连接mysql失败的解决过程

package mysqlconnect;
import java.sql.*;

public class mysqlconnect {
    public static void main(String[] args) {

        //加载数据库驱动

        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        //设置用户信息和url
        String user = "root";            
        String password = "123456";            /*密码*/
        String url = "jdbc:mysql://localhost:3306/student";        /*jdbc:mysql://localhost:3306/数据库中的库名*/
        //获取数据库对象connection
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(url,user,password);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        //通过数据库对象connection获取statement对象
        Statement stat = null;
        try {
            stat = conn.createStatement();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        //执行sql语句
        String sql = "insert into admit values ('123','123')";            /*为student数据库里admit表加值*/
        try {
            stat.executeUpdate(sql);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        //释放连接资源
        try {
            stat.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            conn.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }    
    }
}