servelt與session實現登入並驗證的原始碼
阿新 • • 發佈：2019-01-10
（1）登入index.jsp介面
（2）輸入驗證碼錯誤
（3）輸入驗證碼成功
（4）在webroot底下新建一個index.jsp檔案
index.jsp檔案
（5）DoLogin.java檔案<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> </head> <body> <% String msg = (String)request.getAttribute("msg"); if(msg!=null){ out.print(msg); } %> <form action="/day10_01_HttpSession/servlet/doLogin" method="post"> 使用者名稱：<input type="text" name="userName"/><br> 密碼：<input type="password" name="pwd"/><br> 驗證碼：<input type="text" name="code"/> <img src="/day10_01_HttpSession/servlet/codeServlet" onclick="changeCode()"/><a href="javascript:changeCode()" >看不清換一張</a><br> <input type="submit" value="登入"/><br> </form> </body> </html>
package com.itheima.servlet; 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 DoLogin extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); //獲取表單資料 String userName = request.getParameter("userName"); String pwd = request.getParameter("pwd"); String code = request.getParameter("code"); String scode = (String) request.getSession().getAttribute("scode"); //處理業務邏輯 if("tom".equals(userName)&&"123".equals(pwd)){ //分發 if(!code.equalsIgnoreCase(scode)){ request.setAttribute("msg", "驗證碼錯誤！！！"); request.getRequestDispatcher("/index.jsp").forward(request, response); } out.print("登入成功！！！"); } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
（6）CodeServlet.java檔案
package com.itheima.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import cn.dsna.util.images.ValidateCode; public class CodeServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ValidateCode vc = new ValidateCode(110, 25, 4, 9);//寬度110 高度25 驗證碼4 干擾線9個 //向session中儲存驗證碼 request.getSession().setAttribute("scode", vc.getCode()); vc.write(response.getOutputStream()); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }