JSP第六次作业提交~~~~~~~~~~~~~~~~~~~~~

1.安装MySQL数据库，建立用户表 uid uname upwd 并插入3条数据 (利用注册页面创建的数据)

2.制作jsp登录页面 login.jsp 提交到dologin.jsp，使用jdbc连数据库，判断输入的用户名密码是否存在

package com.example.servlet;

import com.example.Dao.ConnectionPool;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.sql.*;

public class Login extends HttpServlet {
    @Override
    public void init() throws ServletException {
        super.init();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=UTF-8");
        String uusername = req.getParameter("username").trim();
        String ppassword = req.getParameter("password").trim();
        int code1Int= 0;
        int code2Int= 0;
        int yzmInt= 0;
        Connection connection=null;
        PreparedStatement pre=null;
        try {
             connection = ConnectionPool.pop();
            String sql="SELECT * FROM USER WHERE user_name=? AND user_password=?;";
             pre = connection.prepareStatement(sql);
            pre.setString(1,uusername);
            pre.setString(2,ppassword);
            ResultSet rs = pre.executeQuery();
            boolean m = rs.next();
            if (code1Int+code2Int==yzmInt){
                try {
                    String yzm=req.getParameter("verify").trim();
                    String code1=req.getParameter("code1").trim();
                    String code2=req.getParameter("code2").trim();
                    code1Int = Integer.parseInt(code1);
                    code2Int = Integer.parseInt(code2);
                    yzmInt = Integer.parseInt(yzm);
                    if (code1Int+code2Int==yzmInt){
                        if (m==true){
                            HttpSession session = req.getSession();
                            session.setAttribute("uusername",uusername);
                            req.getRequestDispatcher("login_success.jsp").forward(req,resp);
                        }else {
                            resp.getWriter().println("<h1>登陆失败<h1>");
                            resp.getWriter().println("<h1>用户名或密码输入错误<h1>");
                            resp.getWriter().println("<h1>5s后页面跳转....</h1>");
                            resp.getWriter().println("<a href=\"login.jsp\">返回至登陆界面</a>");
                            resp.setHeader("Refresh","5;url=login.jsp");
                        }
                    }else {
                        resp.getWriter().println("<h1>验证码输入错误<h1>");
                        resp.getWriter().println("<h1>3s后页面跳转....</h1>");
                        resp.getWriter().println("<a href=\"login.jsp\">返回至登陆界面</a>");
                        resp.setHeader("Refresh","3;url=login.jsp");
                    }
                } catch (NumberFormatException e) {
                    resp.getWriter().println("<h1>验证码为空，千万不可以为空哦<h1>");
                    resp.getWriter().println("<h1>3s后页面跳转....</h1>");
                    resp.getWriter().println("<a href=\"login.jsp\">返回至登陆界面</a>");
                    resp.setHeader("Refresh","3;url=login.jsp");
                }
            }

        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }finally {
            try {
                if (pre!=null)
                pre.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
            ConnectionPool.push(connection);
        }

    }
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doGet(req, resp);
    }

    public void success(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

    }
}

3.如果存在，把用户名保存在SESSION中，跳转到welcome.jsp，welcome.jsp中读取session中的用户名，显示欢迎你xxx

<%--
  Created by IntelliJ IDEA.
  User: 86177
  Date: 2021/3/30
  Time: 12:09
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>登陆成功页面</title>
</head>
<body>
<%
    String login= (String) session.getAttribute("uusername");
    if (login==null){
        response.sendRedirect("login.jsp");
    }
%>
 <h1>欢迎你 <%=login%></h1>
</body>
</html>

4.若不存在，跳到登录页面。

5.利用管理员查看所有用户信息

package com.example.servlet;

import com.example.bean.User;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class Admin extends HttpServlet {
    @Override
    public void init() throws ServletException {
        super.init();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=UTF-8");
        String adminuser = req.getParameter("adminuser").trim();
        String adminpassword=req.getParameter("adminpassword").trim();
        if (adminuser.equals("axing")&&adminpassword.equals("11")){
            HttpSession session = req.getSession();
            session.setAttribute("adminuser",adminuser);
            req.getRequestDispatcher("guanli_success.jsp").forward(req,resp);
         }else {
//            resp.getWriter().println("<h1>登陆失败<h1>");
             req.getRequestDispatcher("guanli.jsp").forward(req,resp);
         }
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doGet(req, resp);
    }
}