利用JSP内置对象Request和Application实现用户名密码登录注册进入首页显示

本文介绍: ◆(1 )改进注册功能,注册成功将用户注册信息保存在application中。(2)改进登录功能,将用户登录信息跟application中存储的进行比对校验，若登录成功进入主页并将账号存入session ,若登录失败回到登录页面。

1、实验
■地点:周三2单元，10617综合一实验室,自带电脑
■目的:掌握各种内置对象的主要使用方法,能使用内置对象完成具体的功能。
■内容:
◆(1 )改进注册功能,注册成功将用户注册信息保存在application中。(2)改进登录功能,将用户登录信息跟ap pli cat i on中存储的进行比对校验，若登录成功进入主页并将账号存入session ,若登录失败回到登录页面。
■要求:
实验课前着手实验
&g t;实验课最后半小时组长组织小组演示验收，互评打分,组长将最终成绩发给老师
◆本次写实验报告,上传学习通
实验课上小组互评打分标准:
90-100分:完成实验,运行效果好。
80-89分:基本完成实验或有瑕疵,运行效果– -般。70-79分:实验进行了一半以上。
60-69 :实验进行了不到- -半。
60分以下:还在学习消化,没有开始实验。

&lt;%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%&gt;

&lt;html>
<body>
<h2>欢迎来到主页面!</h2>
<%
    request.setCharacterEncoding("utf-8");
    String username = request.getSession().getAttribute("username").toString();
%>
<h3 style="color: red">您好，<%=username %></h3>

</body>
</html>

<%--
  Created by IntelliJ IDEA.
  User: baizhimin
  Date: 2023/3/23
  Time: 22:08
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Login Page</title>
</head>
<body>
<h1>登录页面</h1>
<form action="login_deal.jsp" method="POST">
    <label for="username">用户名:</label>
    <input type="text" id="username" name="username" required>
    <br><br>
    <label for="password">密码:</label>
    <input type="password" id="password" name="password" required>
    <br><br>
    <input type="submit" value="登录">
</form>
<br>
<p>没有账户? <a href="register.jsp">点击注册</a></p>
</body>
</html>

<%@ page import="java.util.HashMap" %><%--
  Created by IntelliJ IDEA.
  User: baizhimin
  Date: 2023/3/23
  Time: 22:11
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Login_deal</title>
</head>
<body>
<%
    request.setCharacterEncoding("utf-8");
    String path = request.getContextPath();
    String username = request.getParameter("username");
    String password = request.getParameter("password");
    request.getSession().setAttribute("username",username);
    HashMap<String,String> userMap = (HashMap<String,String>)application.getAttribute("userMap");

    if(userMap==null){
        out.print("登录失败! 即将返回登录界面");
        response.setHeader("refresh","2;url="+path+"/login.jsp");
    }else{
        String pwd = userMap.get(username);
        if(pwd!=null &amp;&amp; pwd.equals(password)){
            session.setAttribute("username", username);
            out.print("登录成功! 即将返回主页面");
            response.setHeader("refresh","2;url="+path+"/index.jsp");
        }else{
            out.print("登录失败! 即将返回登录界面");
            response.setHeader("refresh","2;url="+path+"/login.jsp");
        }
    }

%>
</body>
</html>

<%--
  Created by IntelliJ IDEA.
  User: baizhimin
  Date: 2023/3/23
  Time: 22:08
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Registration Page</title>
</head>
<body>
<h1>注册页面</h1>
<form action="register_deal.jsp" method="POST">
    <label for="username">用户名:</label>
    <input type="text" id="username" name="username" required>
    <br><br>
    <label for="password">密码:</label>
    <input type="password" id="password" name="password" required>
    <br><br>
    <input type="submit" value="注册" onclick="alert('注册成功')">
</form>
<br>
<p>已有账户? <a href="login.jsp">点击登录</a></p>
</body>
</html>

<%@ page import="java.util.HashMap" %><%--
  Created by IntelliJ IDEA.
  User: baizhimin
  Date: 2023/3/23
  Time: 22:09
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>register_deal</title>
</head>
<body>
<%
    request.setCharacterEncoding("utf-8");
    String path = request.getContextPath();
    String username = request.getParameter("username");
    String password = request.getParameter("password");
    request.getSession().setAttribute("username",username);
    HashMap<String,String> userMap = (HashMap<String,String>)application.getAttribute("userMap");

        if(userMap==null){
            userMap = new HashMap<String,String>();
            userMap.put(username,password);
            application.setAttribute("userMap",userMap);
            out.print("注册成功! 即将返回主页面");
            response.setHeader("refresh","2;url="+path+"/index.jsp");
        }else{
            if(userMap.containsKey(username)){
                out.print("账号已存在! 即将返回注册页面");
                response.setHeader("refresh","2;url="+path+"/register.jsp");
            }else{
                userMap.put(username, password);
                out.print("注册成功! 即将返回主页面");
                response.setHeader("refresh","2;url="+path+"/index.jsp");
            }
        }

%>
</body>
</html>

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.example</groupId>
  <artifactId>WebTest5</artifactId>
  <version>1.0-SNAPSHOT</version>
  <dependencies>
    <dependency>
      <groupId>jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>

    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
      <scope>provided</scope>
    </dependency>

    <!--jsp-->

    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>jsp-api</artifactId>
      <version>2.2</version>
      <scope>provided</scope>
    </dependency>

  </dependencies>
  <packaging>war</packaging>
  <!--servlet-->

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.tomcat.maven</groupId>
        <artifactId>tomcat7-maven-plugin</artifactId>
        <version>2.2</version>

        <configuration>
          <path>/</path> <!--项目访问路径。当前配置的访问是localhost:9090/, 如果配置是/aa，则访问路径为localhost:9090/aa -->
          <port>9090</port>


<!--          <url>http://localhost:9090/register.jsp</url>-->
          <uriEncoding>UTF-8</uriEncoding><!-- 非必需项 -->
        </configuration>

      </plugin>
    </plugins>
  </build>



</project>

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>
</web-app>