JDBC链接出错

package cn.sql;



import java.sql.*;



public class DataBase

{

	static final String	JDBC_DRIVER	="com.mysql.jdbc.Driver";

	static final String	DB_URL		= "jdbc:mysql//localhost:3306/qb";



	static final String	USER		= "root";

	static final String	PASS		= "";



	public static void main(String[] args) throws SQLException

	{

		Connection con = null;

		Statement sta = null;

		try

		{

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

		} catch (ClassNotFoundException e)

		{

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

			con = DriverManager.getConnection(DB_URL,USER, PASS);

			sta = con.createStatement();

			String sql;

			sql = "stlect id,top, from qc";

			ResultSet rs = sta.executeQuery(sql);

			System.out.println("输出ssss"+rs);

			rs.close();

			sta.close();

			con.close();



			// TODO: handle exception

		}

	}