一般來說我們的項目都有登入過濾器,一般請求足以搞定。但是AJAX卻是例外的,所以解決方案是設定響應為session失效。
一共分為過濾器和頁面JS兩個部分的設定,先看過濾器的修改:
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.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;/** * 登入過濾器 * 擁有Session是否失效和使用者是否登入2個條件判斷 * 如果是ajax請求則設定session逾時 * @author Merlin.Ma * */public class LoginFilter implements Filter{ private String redirectUrl = "/login.html"; private String sessionKey = "userName"; @Override public void destroy() { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest req = (HttpServletRequest) request; HttpServletResponse rep = (HttpServletResponse) response; HttpSession session = req.getSession(); if( session == null || session.getAttribute(sessionKey) == null){ //如果判斷是 AJAX 請求,直接設定為session逾時 if( req.getHeader("x-requested-with") != null && req.getHeader("x-requested-with").equals("XMLHttpRequest") ) { rep.setHeader("sessionstatus", "timeout"); } else { rep.sendRedirect( req.getContextPath() + redirectUrl); } }else { chain.doFilter(request, response); } } @Override public void init(FilterConfig filterConfig) throws ServletException { String url = filterConfig.getInitParameter("redirectUrl"); String key = filterConfig.getInitParameter("sessionKey"); redirectUrl = url == null? redirectUrl:url; sessionKey = key == null ? sessionKey : key ; }}
代碼簡單,就不過多進行注釋了,現在看JS部分的代碼。當然是基於jQuery的~~
//全域的ajax訪問,處理ajax清求時sesion逾時 $.ajaxSetup({ contentType : "application/x-www-form-urlencoded;charset=utf-8", complete : function(XMLHttpRequest, textStatus) { var sessionstatus = XMLHttpRequest.getResponseHeader("sessionstatus"); // 通過XMLHttpRequest取得回應標頭,sessionstatus, if (sessionstatus == "timeout") { // 如果逾時就處理 ,指定要跳轉的頁面 window.location.replace("login.html"); } }});
頁面載入這段js代碼,然後開始調用ajax。在不登陸或者session失效的情況下,可以看到頁面跳轉到登入頁面。