数据库链接异常怎么处理啊，shopping已在navicat创建

package util;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.SQLException;

public class DBHelper {

//数据库驱动

   private static final String driver = "com.mysql.jdbc.Driver";

   //链接数据库的URL地址

   private static final String url="jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF";

   //数据库的用户名

   private static final String username = "root";

   //数据库的密码

   private static final String password = "";//

   private static Connection conn=null;

   //静态代码块负责加载驱动

    static

    {

    try

    {

    Class.forName(driver);

    }

    catch(Exception ex)

    {

    ex.getStackTrace();

    }

    }

    //单例模式返回数据库连接对象

    public static Connection getConnection() throws Exception

    {

    if(conn!=null)

    {

    conn = DriverManager.getConnection(url, username, password);

       return conn;

    }

    return conn;

    }

    public static void main(String[] args) {

    try

    {

    Connection conn = DBHelper.getConnection();

    if(conn!=null)

    {

    System.out.println("数据库连接正常！");

    }

    else

    {

    System.out.println("数据库连接异常！");

    }

    }

    catch(Exception ex)

    {

     ex.getStackTrace();

    }

}

}