Spring MVC - keep request parameters after redirect

Question

I have a situation here where my frontend developer wants to add several parameters to every link. He needs those as parameters in the view where the link points to.

Each @Controller method will return Strings only. This is backed by a standard viewresolver using said String as viewname:

<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"
        p:prefix="/WEB-INF/jsp/" p:suffix=".jsp" />

Whenever the Controller returns a redirect: however, the request parameters from the original request are dropped and he can not access them in the .jsp

Is there any neat way to ensure that even after redirect:'ing, the url parameters are present in the view which was redirected to?

Answer 1

You need a flash scope. It is already implemented from spring 3.1.RC1 onward - see the request

Answer 2

Since the solutions suggested by Bozho where not quite satisfactory for my needs, I wrote a filter which does exactly what I want. Not sure if any problems might occur in future cases but until then, feel free to use my implementation:

/**
*
* @author Lennart Koester (University of Innsbruck, 2012)
*/
@Service
public class RedirectFilter implements Filter {

@Override
public void init(FilterConfig filterConfig) throws ServletException {
}

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

    String queryString = ((HttpServletRequest) request).getQueryString();
    if (queryString != null) {
        RedirectAwareResponseWrapper res = new RedirectAwareResponseWrapper((HttpServletResponse) response);
        chain.doFilter(request, res);
        if (res.isRedirected()) {
            ((HttpServletResponse) response).sendRedirect(res.getLocation() + "?" + queryString);
        }
    } else {
        chain.doFilter(request, response);
    }
}

@Override
public void destroy() {
}

class RedirectAwareResponseWrapper extends HttpServletResponseWrapper {

    private boolean redirected = false;
    private String location;

    public RedirectAwareResponseWrapper(HttpServletResponse response) {
        super(response);
    }

    @Override
    public void sendRedirect(String location) throws IOException {
        redirected = true;
        this.location = location;
        //IMPORTANT: don't call super() here
    }

    public boolean isRedirected() {
        return redirected;
    }

    public String getLocation() {
        return location;
    }

}
}