无法使用session.invalidate（）清除用户信息

时间：2018-07-12 09:21:41

标签： java jsp servlets

我正在尝试编写一个非常简单的登录应用程序。当用户输入checklogin.do的url路径时，请求将由CheckLoginStatus servlet处理。然后，该Servlet将请求传递到相应的页面。如果这不是一个新会话，则请求将转发到form.html以要求他们登录，否则将显示cookieresult.jsp页面。该页面可以通过单击CheckCookie将用户引导到click here servlet，最后将返回formresult.jsp。通过单击logout，该会话将无效。

问题在于，即使我已经注销，每当我尝试返回登录页面时，我仍会被重定向到“ cookieresult.jsp”，这意味着我的cookie和属性仍然存在。有什么办法解决这个问题吗？任何建议将不胜感激。

CheckLoginStatus.java 

package com.example.web;

import java.io.*;
import javax.servlet.http.*;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;

/**
 * Servlet implementation class CheckLoginStatus
 */
@WebServlet(description = "which one container returns, login or welcome page", urlPatterns = { "/CheckLoginStatus" })
public class CheckLoginStatus extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        // create session
        HttpSession session = request.getSession();
        session.setMaxInactiveInterval(10);

        if(session.isNew()) {
            response.sendRedirect("form.html");
        }
        else {
            Cookie[] cookies = request.getCookies();
            for(int i = 0; i < cookies.length; i++) {
                if(cookies[i].getName().equals("username")) {
                    Cookie cookie = cookies[i];
                    String usr = cookie.getValue();
                    if(usr != null) {
                        request.setAttribute("username", usr);
                        RequestDispatcher view = request.getRequestDispatcher("cookieresult.jsp");
                        view.forward(request, response);
                    }
                    else {
                        RequestDispatcher view = request.getRequestDispatcher("form.html");
                        view.forward(request, response);
                    }
                    break;
                }
            }
        }

    }

}

form.html 

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
</head>
<body>
<h1 align="center">Simple Session and Cookie Practice</h1>
<form method="POST" action="cookietest.do">
    <div style="text-align:center;">
        Username: <input type="text" name="username"><br>
        Passord: <input type="password" name="password"><br>

        <input type="submit" value="Submit">
    </div>
</form>
</body>
</html>

CookieTest.java 

package com.example.web;

import java.io.IOException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;

/**
 * Servlet implementation class CookieTest
 */
@WebServlet(description = "create and setup cookie", urlPatterns = { "/CookieTest" })
public class CookieTest extends HttpServlet {
    private static final long serialVersionUID = 1L;

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {


        String usr = request.getParameter("username");
        String pwd = request.getParameter("password");

        request.setAttribute("username", usr);
        request.setAttribute("password", pwd);

        Cookie cookieUsr = new Cookie("username", usr); // put usr info on cookie
        cookieUsr.setMaxAge(60);
        response.addCookie(cookieUsr); // add cookie to response

        Cookie cookiePwd = new Cookie("password", pwd); // put pwd info on cookie
        cookiePwd.setMaxAge(60);
        response.addCookie(cookiePwd); // add cookie to response

        RequestDispatcher view = request.getRequestDispatcher("cookieresult.jsp");
        view.forward(request, response);
    }

}

cookieresult.jsp 

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
</head>
<body>
<div style="text-align:center">
<%
String usr = (String) request.getAttribute("username");
out.println("<h1 align=center>Hi " + usr + "!</h1><br>");
%>

<a href="checkcookie.do">click here</a>
</div>
</body>
</html>

CheckCookie.java 

package com.example.web;

import java.io.*;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;

/**
 * Servlet implementation class CheckCookie
 */
@WebServlet(description = "get usr and return result to client", urlPatterns = { "/CheckCookie" })
public class CheckCookie extends HttpServlet {
    private static final long serialVersionUID = 1L;

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        RequestDispatcher view = request.getRequestDispatcher("formresult.jsp");
        Cookie[] cookies = request.getCookies();

        // model
        // password is also in cookie, but not being used here
        for(int i = 0; i < cookies.length; i++) {
            if(cookies[i].getName().equals("username")) {
                Cookie cookie = cookies[i];
                String usr = cookie.getValue();
                request.setAttribute("username", usr);
                break;
            }
        }

        // view
        view.forward(request, response);
    }

}

formresult.jsp 

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
</head>
<body>
<%
String usr = (String) request.getAttribute("username");

out.println("<h1>" + usr + ", here is your information.</h1><br>");
out.println("blablabla<br>");
%>

<div style="text-align:center">
    <a href="logout.do">click to logout</a>
</div>
</body>
</html>

web.xml 

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" id="WebApp_ID" version="4.0">
  <servlet>
    <servlet-name>cookie tester</servlet-name>
    <servlet-class>com.example.web.CookieTest</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>cookie tester</servlet-name>
    <url-pattern>/cookietest.do</url-pattern>
  </servlet-mapping>
  <servlet>
    <servlet-name>check cookie</servlet-name>
    <servlet-class>com.example.web.CheckCookie</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>check cookie</servlet-name>
    <url-pattern>/checkcookie.do</url-pattern>
  </servlet-mapping>
  <servlet>
    <servlet-name>check login</servlet-name>
    <servlet-class>com.example.web.CheckLoginStatus</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>check login</servlet-name>
    <url-pattern>/checklogin.do</url-pattern>
  </servlet-mapping>
  <servlet>
    <servlet-name>logout</servlet-name>
    <servlet-class>com.example.web.CheckLogout</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>logout</servlet-name>
    <url-pattern>/logout.do</url-pattern>
  </servlet-mapping>
  <listener>
    <listener-class>com.example.web.MySessionCounter</listener-class>
  </listener>
  <session-config>
    <session-timeout>2</session-timeout>
  </session-config>
</web-app>

0 个答案:

没有答案
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