基於JSP+Servlet的使用者登入驗證
阿新 • • 發佈：2019-02-02
要求：實現一個簡單的使用者登驗證程式.如果使用者名稱和密碼都正確，顯示歡迎資訊. 否則顯示“登入失敗”
分析：採用jsp頁面完成提交資訊和驗證結果的顯示，而驗證過程由Servlet來完成，由於沒涉及到資料庫技術，所以使用者名稱和密碼都是事先確定好的，這些元件通過request物件實現物件共享.
設計：
1.登入表單頁面 login.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head><title>登入頁面</title></head> <body> <form action="loginCheck" method="post"> 請輸入使用者名稱：<input type="text" name="username"/><br/> 請輸入密碼：<input type="password" name="userpassword"/><br/> <input type="submit" name="登入"> </form> </body> </html>
2.處理驗證過程的Servlet LoginCheckServlet.java
package my; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class LoginCheckServlet extends HttpServlet { public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); String userName=request.getParameter("username"); String userPassword=request.getParameter("userpassword"); String info=""; if(("wcz".equals(userName))&& "1234".equals(userPassword)) { info="歡迎你"+userName+"!"; request.setAttribute("info1", info); request.getRequestDispatcher("/success.jsp").forward(request, response); }else{ request.getRequestDispatcher("/fail.jsp").forward(request, response); } } public void init() throws ServletException { // Put your code here } }
<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">
</span><span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">3.登入成功的頁面 </span><span style="font-family: Calibri; background-color: rgb(255, 255, 255);">success.jsp</span>
<span style="font-family: Calibri; background-color: rgb(255, 255, 255);">
</span><span style="font-family: Calibri; background-color: rgb(255, 255, 255);"></span><pre name="code" class="html"><%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head><title>登入成功頁面</title></head>
<body>
<p align="center">登入成功<%=request.getAttribute("info1") %>
</p>
</body>
</html>4.登入失敗的頁面 faile.jsp
<span style="font-family: Calibri; background-color: rgb(255, 255, 255);"></span><pre name="code" class="html"><%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head><title>登入失敗頁面</title></head>
<body>
<p align="center">登入失敗.<a href= "login.jsp">請重新登入</a>
</p>
</body>
</html>
5.web.xml檔案的配置
<servlet-mapping>
<servlet-name>LoginCheckServlet</servlet-name>
<url-pattern>/loginCheck</url-pattern> 此處要換成<span style="font-family: Calibri;">/loginCheck 與login.jsp中相對應.</span>
</servlet-mapping> 下面是對部分結果的截圖：