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JSP實現(xiàn)簡單的登錄和注冊界面詳細全過程

更新時間：2024年04月27日 11:43:26 作者："wxzk

用戶注冊是指用戶在網(wǎng)站上創(chuàng)建新的賬號,而用戶登錄是指已注冊的用戶通過輸入正確的賬號和密碼進入自己的賬號,下面這篇文章主要給大家介紹了關(guān)于JSP實現(xiàn)簡單的登錄和注冊界面的相關(guān)資料,需要的朋友可以參考下

1、login.jsp

login.jsp中username和password在LoginSelect.jsp驗證是否一致
使用session.setAttribute("login_msg","用戶名或密碼為空")設(shè)置login_msg的值
使用session.getAttribute("login_msg")獲取對象的值，判斷輸入框是否為空，如果為空，則提示用戶名或密碼為空。

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>登錄界面</title>
</head>
<body>

<div align="center">
    <h1>歡迎登錄</h1>
    <form action="LoginSelect.jsp" method="post" id="form">
        <p>用戶名:&nbsp<input id="username" name="username" type="text">&nbsp&nbsp</p>
        <p>密碼:&nbsp<input id="password" name="password" type="password"></p>
            <input type="submit" class="button" value="登錄" onclick="">
            <button><a href="register.jsp" rel="external nofollow" >注冊</a></button>
    </form>
    <div id="errorMsg" value="null"><%=session.getAttribute("login_msg")%></div>
</div>

<script>
    if(document.getElementById("errorMsg").innerText==="null"||document.getElementById("errorMsg").innerText===""){
        document.getElementById("errorMsg").setAttribute('style',"display:none")

    } else {
        document.getElementById("errorMsg").setAttribute('style',"display:block")
    }
</script>

</body>
</html>

2、 loginSelect.jsp

利用Map集合存儲賬戶和密碼信息，模擬數(shù)據(jù)庫
map.put("20201234","123456")設(shè)置初始數(shù)據(jù)
map.put(username,session.getAttribute(username).toString())這里是將注冊的賬戶和密碼添加到數(shù)據(jù)庫中，username為鍵，session.getAttribute(username).toString()為值，兩者都為字符串類型

<%@ page import="java.util.*" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>判斷登錄界面</title>
</head>
<body>

<%!
     Map<String,String> map = new HashMap<String,String>();
     public boolean compare(String username,String password){
         String pwd = map.get(username);
         if(pwd!=null&&password.equals(pwd)){
             return true;
         }
         else{
             return false;
         }
     }
%>
<%
    String username = request.getParameter("username");
    String password = request.getParameter("password");
    //設(shè)置初始值
    map.put("20201234","123456");
    //注冊后的值存入map集合
    if (session.getAttribute(username)!=null){
        map.put(username,session.getAttribute(username).toString());
    }

    System.out.println(map);
    //判斷輸入內(nèi)容是否正確,給出提示信息
    if (username==null||username =="" || password==null || password==""){
        session.setAttribute("login_msg","用戶名或密碼為空");
        response.sendRedirect("login.jsp");
        return;
    }
    boolean compare = compare(username, password);
    if (compare){
        session.setAttribute("username",username);
        session.setAttribute("password",password);
        response.sendRedirect("index.jsp");
    }
    else {
        session.setAttribute("login_msg","用戶名或密碼錯誤或用戶名不存在");
        response.sendRedirect("login.jsp");
    }
%>
</body>
</html>

3、register.jsp

register.jsp中username和password在RegisterSelect.jsp驗證是否一致
使用session.setAttribute("register_msg","用戶名或密碼為空")設(shè)置register_msg的值
使用session.getAttribute("register_msg")獲取對象的值，判斷輸入框是否為空，如果為空，則提示用戶名或密碼為空。

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
  <title>注冊界面</title>
</head>

  <div align="center">
    <h1>歡迎注冊</h1>
  <form action="RegisterSelect.jsp" method="post">
    <table>
      <tr>
        <td>用戶名</td>
        <td>
          <input name="username" type="text" id="username">
          <br>
        </td>
      </tr>
      <tr>
        <td>密碼</td>
        <td>
          <input name="password" type="password" id="password">
          <br>
        </td>
      </tr>
    </table>
      <input value="注 冊" type="submit" id="reg_btn"><br>
    <span>已有帳號？</span> <a href="login.jsp" rel="external nofollow"  rel="external nofollow" >登錄</a>
  </form>
    <span id="register_msg" class="err_msg" ><%=session.getAttribute("register_msg")%></span>
  </div>
</body>
</div>
<script>
  if(document.getElementById("register_msg").innerText==="null"||document.getElementById("register_msg").innerText===""){
    document.getElementById("register_msg").setAttribute('style',"display:none")

  } else {
    document.getElementById("register_msg").setAttribute('style',"display:block")
  }
</script>
</html>

4、 RegisterSelect.jsp

if else語句，if 判斷賬戶或密碼為空則提示"用戶或密碼為空"，else 使用session.setAttribute(username,password) 創(chuàng)建對象存儲新的賬戶和密碼信息。

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
    String username = request.getParameter("username");
    String password = request.getParameter("password");
    session.setAttribute("register_msg","null");

    if (username==null||username =="" || password==null || password==""){
        session.setAttribute("register_msg","用戶名或密碼為空");
        response.sendRedirect("register.jsp");
        return;
    }
    else {
        session.setAttribute(username,password);
        response.sendRedirect("login.jsp");
    }
%>
<html>
<head>
    <title>Title</title>
</head>
<body>

</body>
</html>

5、 index.jsp

session.getAttribute("username")動態(tài)獲取賬戶名稱

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>登錄成功</title>
</head>
<body>
<div align="center">
    <h1>JSP管理系統(tǒng)</h1>
<h1><%=session.getAttribute("username")%> 歡迎您!</h1>
<a href="login.jsp" rel="external nofollow"  rel="external nofollow" >退出登錄</a>
</div>
</body>
</html>