预生命的登陆

package com.lianxi;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Scanner;

public class TestSign {
    public static void main(String[] args) throws Exception {
        Class.forName("com.mysql.jdbc.Driver");
        Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/boooks","root","tiger");
        Statement st=conn.createStatement();
        Scanner s=new Scanner(System.in);    
        System.out.println("用户名");
        String name=s.nextLine();
        System.out.println("密码");
        String pwd=s.nextLine();
    
        String sql="select * from tb_user where userName=? and password=?";
            //创建ps
        PreparedStatement ps=conn.prepareStatement(sql);
        //赋值
        ps.setString(1,name );
        ps.setString(2, pwd);
        ResultSet rs=ps.executeQuery();
        if(rs.next()){
            System.out.println("登陆成功");
        }else{
            System.out.println("用户名或密码错误");
        }
        rs.close();
        st.close();
        conn.close();
    }

}