protected void saveRequestAndRedirectToLogin(ServletRequest request, ServletResponse response) throws IOException {
        saveRequest(request);
        redirectToLogin(request, response);
    }
Convenience method for subclasses to use when a login redirect is required.
<p/>
This implementation simply calls {@link #saveRequest(javax.servlet.ServletRequest) saveRequest(request)}
and then {@link #redirectToLogin(ServletRequest, ServletResponse) redirectToLogin(request,response)}.

@param request  the incoming <code>ServletRequest</code>
@param response the outgoing <code>ServletResponse</code>
@throws IOException if an error occurs.
web/src/main/java/org/apache/shiro/web/filter/AccessControlFilter.java