Question

In Spring MVC 2.5 with Jetty – probably with any servlet container -, I want to redirect to an external site using RedirectView via the magic “redirect:” prefix for the view name in ModelAndView.

Unfortunately, RedirectView uses response.encodeRedirectURL(), so my (otherwiese wanted) session id is appended to the URL. It is not only a security risk to carry the session id to the external site, the “;jsessionid=gagnbaba” string may also be interpreted as part of the ContextPath/PathInfo on the other site, resulting in a bad URL.

Any “springish” options other than implement my own ExternalRedirectView… and also hack the ViewResolver to interpret a “externalRedirect:” prefix? (Requiring cookies is not an option.)

Moritz

Answer 1

Now here is ExternalRedirectView as planned in my comment above… did it that way.

import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.view.RedirectView;

/** variant of RedirectView, will not add a session id to the url
 */
public class ExternalRedirectView extends RedirectView {
    public ExternalRedirectView(String url, boolean contextRelative) {
        super(url, contextRelative);
    }

    /** copied from @link{RedirectView#sendRedirect} and removed calls to
     * reponse.encodeRedirectURL()
     */
    @Override
    protected void sendRedirect( HttpServletRequest request,
            HttpServletResponse response, String targetUrl,
            boolean http10Compatible ) throws IOException {
        if (http10Compatible) {
            // Always send status code 302.
            response.sendRedirect(targetUrl);
        }
        else {
            // Correct HTTP status code is 303, in particular for POST requests.
            response.setStatus(303);
            response.setHeader("Location", targetUrl);
        }
    }
}

I also already had my own ViewResolver in which I added the functionality for the new externalRedirect: magic vier name prefix, which now reads:

class MyViewResolver extends AbstractCachingViewResolver implements BeanFactoryAware {
[...]
    private static final String EXTERNAL_REDIRECT_URL_PREFIX = "externalRedirect:";
[...]
    @Override
    protected View loadView( String viewName, Locale locale ) throws Exception {
        View view;
        if (viewName.startsWith(UrlBasedViewResolver.REDIRECT_URL_PREFIX)) 
        {
            view = new RedirectView(viewName.substring(UrlBasedViewResolver.REDIRECT_URL_PREFIX.length()), true);
        }
        else if (viewName.startsWith(EXTERNAL_REDIRECT_URL_PREFIX)) 
        {
            view = new ExternalRedirectView(viewName.substring(EXTERNAL_REDIRECT_URL_PREFIX.length()), true);
        }
        else 

[…]
Thanks to everyone who read this and thought about it.