import java.sql.*;
import java.util.*;

/**
 * 类描述：使用PrepareStatement实现登录验证
 * Author: WuChu
 * Date: 2021/8/2 22:53
 * Version: 1.0
 */
public class PrepareStatementTest {
    public static void main(String[] args) {
        //初始化界面
        //新建一个用户信息Map=集合对象
        Map<String,String> userInfo = Init();

        //判断是否合法
        boolean ok = CheckLogin(userInfo.get("uName"),userInfo.get("pWord"));

        //输出结果
        System.out.println(ok?"登录成功！":"账号或密码错误！");

    }


    /**
     * 初始化界面
     * @return  userInfo
     */
    private static Map<String,String> Init(){
        System.out.println("********欢迎使用系统，请输入账号密码确认身份*******");
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入账号：");
        String uName = scanner.next();
        System.out.print("请输入密码：");
        String pWord = scanner.next();

        //将用户输入的用户名和密码放在Map集合中
        Map<String,String> userInfo = new HashMap<>();
        userInfo.put("uName",uName);
        userInfo.put("pWord",pWord);

        //返回Map集合
        return userInfo;

    }

    /**
     * 连接数据库，判断账号密码是否合法
     * @param userName 用户输入的账号
     * @param passWord 用户输入的密码
     * @return TRUE or FALSE
     */
    private static boolean CheckLogin(String userName,String passWord){

        //先定义一些全局变量
        Connection connection = null;
        PreparedStatement ps = null;
        ResultSet rs ;
        boolean ok = false;

        //资源绑定器
        ResourceBundle resourceBundle = ResourceBundle.getBundle("userInfo");
        String driver = resourceBundle.getString("driver");
        String url = resourceBundle.getString("url");
        String username = resourceBundle.getString("username");
        String password = resourceBundle.getString("password");

        //连接数据库
        try {
            //1、注册数据库驱动
            Class.forName(driver);

            //2、获取数据库连接
            connection = DriverManager.getConnection(url,username,password);

            //3、获取预编译的数据库操作对象
            String sql = "select * from user where username = '" + userName+"' and password = '"+ passWord +"'";
            ps = connection.prepareStatement(sql);

            //4、执行SQL语句
            rs = ps.executeQuery();

            if(rs.next()){
                ok = true;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {

            //6、关闭连接
            if(ps!=null){
                try {
                    ps.close();
                } catch (SQLException se) {
                    se.printStackTrace();
                }
            }
            if(connection!=null){
                try {
                    connection.close();
                } catch (SQLException se) {
                    se.printStackTrace();
                }
            }
        }
        return ok;
    }

}