1.问题描述：

最近自己在写demo时遇到一个问题，在ajax请求时用Filter做登录拦截，结果页面不跳转(Ajax是不能做转发和重定向的)、、、、

最终的最终在同事zt的提示下，恍然大悟，虽然很基本的问题，但也纠结了好久，只能说太菜，记录下来，以免以后再犯。

2.解决办法：

在doFilter方法中判断是否为Ajax请求，做进一步处理

代码如下：

/**

* @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 {

// 过滤掉登陆和退出请求

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:判断是否是ajax请求

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

//向http头添加 状态 sessionstatus

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

resp.setStatus(403);

//向http头添加登录的url

resp.addHeader("loginPath", basePath);

chain.doFilter(request, response);

return ;

}else{

resp.sendRedirect(basePath);

}

}

} else {

//1:判断是否是ajax请求

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

//向http头添加 状态 sessionstatus

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

resp.setStatus(403);

//向http头添加登录的url

resp.addHeader("loginPath", basePath);

chain.doFilter(request, response);

return ;

}else{

resp.sendRedirect(basePath);

}

}

}

} catch (IOException | ServletException e) {

e.printStackTrace();

}

}