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java web实现自动登录功能

2019-11-26 11:07:21
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本文实例为大家分享了java web实现自动登录功能的具体代码,供大家参考,具体内容如下

主要思路就是:当用户访问网站的首页时,浏览器端会先检擦浏览器中存在的cookie中是否又登录的用户的用户名,如果有,则直接跳转至用户登录好的界面,如果没有,则重定向至登录界面,在服务器端创建该用户登录的cookie,响应时,将创建的cookie返回至浏览器端保存。

一、用户访问首页时检查cookie是否存在。

package ahpudong.com;import java.io.IOException;import java.io.PrintWriter;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("/index.do")public class index extends HttpServlet { public index() {  super(); } public void doPost(HttpServletRequest request, HttpServletResponse response)   throws ServletException, IOException {  Cookie[] cookies=request.getCookies();  if(cookies!=null){   for(Cookie cookie:cookies){    String name=cookie.getName();    String value=cookie.getValue();    if("name".equals(name) && "chendong".equals(value)){     request.setAttribute(name, value);     request.getRequestDispatcher("user.view").forward(request, response);     return;    }   }   }   response.sendRedirect("login.jsp"); }}

二、确定用户登录的cookie不存在,在手动登录的过程中创建用户登录cookie。

package ahpudong.com;import java.io.IOException;import java.io.PrintWriter;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.do")public class login extends HttpServlet { public login() {  super(); } public void doPost(HttpServletRequest request, HttpServletResponse response)   throws ServletException, IOException {  response.setContentType("text/html");  request.setCharacterEncoding("utf-8");  response.setCharacterEncoding("utf-8");  PrintWriter out = response.getWriter();  String name=request.getParameter("name");  String pwd=request.getParameter("pwd");  String login=request.getParameter("auto");  if("chendong".equals(name) && "123456".equals(pwd)){   if("on".equals(login)){    Cookie cookie=new Cookie("name","chendong");    cookie.setMaxAge(7*24*60*60);//有效期为一个星期    response.addCookie(cookie);    request.setAttribute("name",name);    request.getRequestDispatcher("user.view").forward(request, response);       }  }else{   response.sendRedirect("login.jsp");  } }}

三、登录成功时的视图层

package ahpudong.com;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@WebServlet("/user.view")public class User extends HttpServlet { public User() {  super(); } public void doGet(HttpServletRequest request, HttpServletResponse response)   throws ServletException, IOException {  processRequest(request,response); } public void doPost(HttpServletRequest request, HttpServletResponse response)   throws ServletException, IOException {  processRequest(request,response); } public void processRequest(HttpServletRequest request,HttpServletResponse response)   throws ServletException, IOException{  response.setCharacterEncoding("utf-8");  PrintWriter out=response.getWriter();  String name=(String) request.getAttribute("name");  out.println("<!DOCTYPE HTML PUBLIC /"-//W3C//DTD HTML 4.01 Transitional//EN/">");  out.println("<HTML>");  out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");  out.println(" <BODY>");  out.println("<h1>"+"welcome "+name+" login"+"</h1>");  out.println(" </BODY>");  out.println("</HTML>");  out.flush();  out.close();  }}

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持武林网。

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