[学习交流] 【广州校区】【原创】使用servlet实现自动登录

本帖最后由 Mylo 于 2018-1-11 17:46 编辑

用户登陆的的时候，讲登录信息添加到session里面，如果勾选了自动登录，那么就讲登录信息同时也添加到Cookie里面

拦截器的逻辑：

拦截所有的请求，放行index.jsp 和login的请求

判断当前的session里面是否有登录的信息如果有的话就放行，

如果当前的session里面没有登录的信息，判断cookie里面是否有登录信息，如果有的话放行

如果当前的session里面既没有登录信息，cookie里面也没有登录信息，就表示是第一次登录

如果请求的不是登录的方法（login）那么就让他进入到登录页面

1. 页面准备

1.1 index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

</head>

<body>

用户登录<br>${msg}

用户名：<input type="text" name="userName"><br>

密码：<input type="password" name="password"><br>

<input type="checkbox" name="auto" value="true"> 七天内内自动登录<br>

</form>

</body>

</html>

1.2 1.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

<body>

测试进入主页

</body>

</html>

2. servlet

package test.mylo.servlet;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.Cookie;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

@WebServlet("/login")

public class LoginSetvlet extends HttpServlet {

private static final long serialVersionUID = 1L;

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

String userName = request.getParameter("userName");

String password = request.getParameter("password");

String auto = request.getParameter("auto");

if(userName.equals("Mylo") && password.equals("Mylo")) {

if(auto!=null && auto.equals("true")) {

Cookie cookie = new Cookie("auto", userName +"="+password);

cookie.setMaxAge(24 * 3600 * 7);

response.addCookie(cookie);

}

request.getSession().setAttribute("loginUser", userName +"="+password);

request.getRequestDispatcher("/1.jsp").forward(request, response);

}else {

request.getSession().setAttribute("msg", "账号或者密码有误");

response.sendRedirect(request.getContextPath() + "/index.jsp");

}

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

doGet(request, response);

}

3. Filter

package test.mylo.servlet;

import java.io.IOException;

import javax.servlet.Filter;

import javax.servlet.FilterChain;

import javax.servlet.FilterConfig;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.annotation.WebFilter;

import javax.servlet.http.Cookie;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

逻辑：拦截所有的请求，放行index.jsp 和login的请求

判断当前的session里面是否有登录的信息如果有的话就放行，

如果当前的session里面没有登录的信息，判断cookie里面是否有登录信息，如果有的话放行

如果当前的session里面既没有登录信息，cookie里面也没有登录信息，就表示是第一次登录

如果请求的不是登录的方法（login）那么就让他进入到登录页面

*/

@WebFilter("/*")

public class AutoFilter implements Filter {

public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {

HttpServletRequest request = (HttpServletRequest)req;

HttpServletResponse response = (HttpServletResponse) resp;

String user =(String) request.getSession().getAttribute("loginUser");

if(user == null) {

Cookie[] cookies = request.getCookies();

boolean flag = false;

if(cookies != null) {

for (Cookie c : cookies) {

if(c.getName().equals("auto")) {

String value = c.getValue();

request.setAttribute("loginUser", value);

flag = true;

break;

}

System.out.println( request.getRequestURI());

if(flag || request.getRequestURI().endsWith("index.jsp") || request.getRequestURI().endsWith("login")) {

chain.doFilter(request, response);

}else {

response.sendRedirect(request.getContextPath() + "/index.jsp");

}

}else {

chain.doFilter(request, response);

}

public void init(FilterConfig fConfig) throws ServletException {

// TODO Auto-generated method stub

}

@Override

public void destroy() {

// TODO Auto-generated method stub

}

帐号		自动登录	找回密码
密码			加入黑马

[学习交流] 【广州校区】【原创】使用servlet实现自动登录

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