Legacy redirector for episerver CMS 5 and 6 urls

LegacyRedirector.cs

using System.Text.RegularExpressions;
using System.Web;
using EPiServer.Core;
using EPiServer.ServiceLocation;
using EPiServer.Web.Routing;

namespace Sintef.Common.Util
{
    public class LegacyRedirector
    {
        public static int GetIdForLegacyUrl(string url)
        {
            var epi5Regex = new Regex(@"(content/\w+|default)____(?<id>\d+)\.aspx", RegexOptions.IgnoreCase);
            var epi5Match = epi5Regex.Match(url);

            var contentId = 0;

            if (epi5Match.Success)
            {
                contentId = int.Parse(epi5Match.Groups["id"].Value);
            }
            else
            {
                var epi6Regex = new Regex(@"content/.+\.aspx\?(.*&)*id=(?<id>\d+)", RegexOptions.IgnoreCase);
                var epi6Match = epi6Regex.Match(url);

                if (epi6Match.Success)
                {
                    contentId = int.Parse(epi6Match.Groups["id"].Value);
                }
            }

            return contentId;
        }

        public static void TryRedirect(HttpRequest request, HttpResponse response, HttpContext context)
        {
            var fullOrigionalpath = request.Url.ToString();

            var contentId = GetIdForLegacyUrl(fullOrigionalpath);

            if (contentId != 0)
            {
                var urlResolver = ServiceLocator.Current.GetInstance<UrlResolver>();

                var contentReference = new ContentReference(contentId);

                var link = urlResolver.GetUrl(contentReference);

                if (!string.IsNullOrEmpty(link))
                {
                    response.RedirectPermanent(link);
                    context.RewritePath(link);
                }
            }
        }
    }
}