1.問題描述：

最近自己在寫demo時遇到一個問題，在ajax請求時用Filter做登錄攔截，結果頁面不跳轉(Ajax是不能做轉發和重定向的)、、、、

最終的最終在同事zt的提示下，恍然大悟，雖然很基本的問題，但也糾結了好久，只能說太菜，記錄下來，以免以后再犯。

2.解決辦法：

在doFilter方法中判斷是否為Ajax請求，做進一步處理

代碼如下：

/**

* @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)

*/

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) {

HttpServletResponse resp=(HttpServletResponse) response;

HttpServletRequest req=(HttpServletRequest) request;

String url = req.getRequestURI();

System.out.println(url);

HttpSession session = ((HttpServletRequest) request).getSession();

String path = req.getContextPath();

String basePath= req.getScheme()+"://"+req.getServerName()+":"+req.getServerPort()+path+"/";

basePath=basePath+"rest/userManager/loginOut";

try {

// 過濾掉登陸和退出請求

if ((url.indexOf("/ddoa/rest/userManager/login") >= 0)|| (url.indexOf("/ddoa/rest/userManager/loginOut") >= 0)) {

chain.doFilter(request, response);

} else {

if (null != session) {

Map map = (Map) session.getAttribute("userMap");

if(null!=map){

chain.doFilter(request, response);

}else{

//1:判斷是否是ajax請求

if (req.getHeader("x-requested-with") != null&& "XMLHttpRequest".equalsIgnoreCase(req.getHeader("x-requested-with"))) {

//向http頭添加 狀態 sessionstatus

resp.setHeader("sessionstatus","timeout");

resp.setStatus(403);

//向http頭添加登錄的url

resp.addHeader("loginPath", basePath);

chain.doFilter(request, response);

return ;

}else{

resp.sendRedirect(basePath);

}

}

} else {

//1:判斷是否是ajax請求

if (req.getHeader("x-requested-with") != null&& "XMLHttpRequest".equalsIgnoreCase(req.getHeader("x-requested-with"))) {

//向http頭添加 狀態 sessionstatus

resp.setHeader("sessionstatus","timeout");

resp.setStatus(403);

//向http頭添加登錄的url

resp.addHeader("loginPath", basePath);

chain.doFilter(request, response);

return ;

}else{

resp.sendRedirect(basePath);

}

}

}

} catch (IOException | ServletException e) {

e.printStackTrace();

}

}