基於session的單點登陸
阿新 • • 發佈：2018-11-10
1、第一次訪問，登入成功
(1)登陸介面
<%@ 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> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <script type="text/javascript" src="jquery-3.2.1/jquery-3.2.1.min.js"></script> <script type="text/javascript"> function login() { var userInfo = { "uname":$("#userName").val(), "upsw":$("#userPwd").val() }; $.getJSON("UserLoginServlet.action",userInfo,function(data){ if(data.success){ //需要完善 window.location.href = "${pageContext.request.contextPath}/HouseInfoShowServlet.action"; }else{ alert("使用者名稱或密碼錯誤，請重新輸入"); $("#userName").focus(); } }); } </script> <title>Insert title here</title> </head> <body> <div> <input type="text" id="userName"/><br/> <input type="password" id="userPwd"/><br/> <button onclick="login()">登入</button> </div> </body> </html>
2、根據使用者名稱和密碼檢查是否有該session，如果有session中存入已登入資訊，覆蓋session
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); String name=request.getParameter("Userame"); String password=request.getParameter("password"); System.out.println(name); System.out.println(password); //List<UserInfo> lists = Methods.selectNamePwd(); UserInfo info = Methods.selectNamePwd(name, password); ResultMsg result; if(info!=null) { checkUser(request); info.setUserName(name); HttpSession session = request.getSession(); session.setAttribute("info", info); response.sendRedirect("HouseShow.action"); result = ResultMsg.success(); }else{ result = ResultMsg.failure("輸入的密碼不正確！請查證！"); request.getRequestDispatcher("login.html").forward(request, response); } response.getWriter().write(JSON.toJSONString(result)); /*for(UserInfo s2:lists) { String name1 = s2.getUserName(); String password2 = s2.getUserPwd(); if(name.equals(name1)&&password.equals(password2)) { response.sendRedirect("HouseShow"); }else { request.getRequestDispatcher("login.html"); } }*/ }
3、如果沒有新增session
private void checkUser(HttpServletRequest request) { String userName = request.getParameter("Userame"); String userPwd = request.getParameter("password"); //獲取上次登入的session(如果有的話) HttpSession session = SessionInfo.USER_SESSION.get(userName+userPwd); if(session!=null) { //在上次登入的session中放入一條資訊 session.setAttribute("msg", ResultMsg.failure("該賬號在另一處登入，是否重新登入")); } //此處有替換session的功能 SessionInfo.USER_SESSION.put(userName+userPwd, request.getSession()); }
4、跳轉到data.jsp介面
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
HttpSession session = request.getSession();
UserInfo info = (UserInfo) session.getAttribute("info");
System.out.println(info.getUserName());
String userName = info.getUserName();
List<HouseInfo> houseInfos = Methods.selectHouse(userName);
session.setAttribute("houseInfos",houseInfos);
request.getRequestDispatcher("/WEB-INF/data.jsp").forward(request, response);
5、在該介面中迴圈訪問checkLogin，獲取資訊
$(function() {
setInterval(checkUserOnline, 5*1000);
});
function checkUserOnline() {
$.getJSON("UserCheckLoginServlet.action",function(data){
if(!data.success){
alert(data.msg);
//登出
window.location.href = "${pageContext.request.contextPath}/UserLogoutServlet.action";
}
});
}
6、如果發現已登入，跳轉到登出servlet中
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("application/json");
ResultMsg msg = (ResultMsg) request.getSession().getAttribute("msg");
//表示未出現重複登入情況
if(msg == null) {
msg = ResultMsg.success();
}
response.getWriter().write(JSON.toJSONString(msg));
}
6、在登出servlet中，使session實效，跳轉到login.jsp
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//登出以後把 物件移除
HttpSession session = request.getSession();
UserInfo userInfo = (UserInfo) session.getAttribute("info");
if(session == SessionInfo.USER_SESSION.get(userInfo.getUserName()+userInfo.getUserPwd())) {
SessionInfo.USER_SESSION.remove(userInfo.getUserName()+userInfo.getUserPwd());
}
//移除session
session.invalidate();
//重定向到登入頁面login.jsp
response.sendRedirect(request.getContextPath()+"/login.html");
}