session 案例實現驗證使用者登入
阿新 • • 發佈：2018-11-05
首頁：
<!DOCTYPE html> <html> <head> <title>login.html</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <!--<link rel="stylesheet" type="text/css" href="./styles.css">--> </head> <body> <form action="/web2/servlet/LoginServlet" method="post"> 使用者名稱：<input type="text" name="username"><br> 密 碼：<input type="password" name ="password"><br> <input type="submit" value="登入"> </form> </body> </html>
user物件
package cn.itcast.shoping; public class User { private String username; private String password; public User(String username, String password) { super(); this.username = username; this.password = password; } public User() { super(); // TODO Auto-generated constructor stub } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }
使用者登入的servlet
package cn.itcast.shoping; import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class LoginServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setCharacterEncoding("utf-8");//第一句，設定伺服器端編碼 response.setContentType("text/html;charset=utf-8");//第二句，設定瀏覽器端解碼 PrintWriter writer = response.getWriter(); String username = request.getParameter("username"); String password = request.getParameter("password"); List<User> list = Db.getall(); for (User user :list){ if(user.getUsername().equals(username) &&user.getPassword().equals(password)){ request.getSession().setAttribute("user", user);//登入成功，向session中存入一個登入標記 response.sendRedirect("/web2/index.jsp"); return; } } writer.println("登入的使用者名稱密碼不正確"); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } } class Db{ public static List list = new ArrayList(); static { list.add(new User("aaa","123")); list.add(new User("bbb","123")); list.add(new User("ccc","123")); } public static List getall(){ return list; } }
登入成功跳轉的頁面：
<%@page import="com.sun.xml.internal.bind.v2.schemagen.xmlschema.Import"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
歡迎你:$(user.username )<a href="/web2/login.html">登入</a><a href="/web2/servlet/LogoutServlet">退出登入</a>
</body>
</html>
登出登入的servlet
package cn.itcast.shoping;
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;
import javax.servlet.http.HttpSession;
//完成使用者登出
public class LogoutServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
HttpSession session = request.getSession(false);
if(session==null){
response.sendRedirect("/seb2/index.jsp");
return;
}
session.removeAttribute("user");
response.sendRedirect("/seb2/index.jsp");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}