Access request Attributes (Set in managed bean before redirect) in Filter by precreating FacesContext

I am setting the request attribute in managed bean before redirect the request through faces-config as follows:

FacesContext.getCurrentInstance().getExternalContext().getRequestMap().put("foo","bar");

return "redirect_success";

After this i m trying to access this request attribute in my filter through pre creating FacesContext

FacesContext.getCurre开发者_高级运维ntInstance().getExternalContext().getRequestMap().get("foo");

Finally not able to get this attribute in filter itself but i am able to get the same attribute again in second managed bean very easily. Is there any way to get it in filter itself?

Two ways:

1. Store in session and let filter remove it from session if necessary.

   externalContext.getSessionMap().put("foo", "bar");
   

   There's by the way no need to create FacesContext yourself in a Filter. Just cast ServletRequest to HttpServletRequest.

   HttpSession session = ((HttpServletRequest) request).getSession();
   String foo = (String) session.getAttribute("foo");
   session.removeAttribute("foo");
   

2. Use ExternalContext#redirect() to add it as request parameter.

   externalContext.redirect("other.jsf?foo=bar");
   

   And then in Filter:

   String foo = ((HttpServletRequest) request).getParameter("foo");