code: public void sendRedirect(String url) 
          throws IOException
      {
          if (url==null)
              throw new IllegalArgumentException();
          
          if (!URI.hasScheme(url))
          {
              StringBuffer buf = _servletHttpRequest.getHttpRequest().getRootURL();
              if (url.startsWith("/"))
                  buf.append(URI.canonicalPath(url));
              else
              {
                  String path=_servletHttpRequest.getRequestURI();
                  String parent=(path.endsWith("/"))?path:URI.parentPath(path);
                  url=URI.canonicalPath(URI.addPaths(parent,url));
                  if (!url.startsWith("/"))
                      buf.append('/');
                  buf.append(url);
              }
              
              url=buf.toString();
          }
          
          resetBuffer();
          
          _httpResponse.setField(HttpFields.__Location,url);
          _httpResponse.setStatus(HttpResponse.__302_Moved_Temporarily);
          complete();
      }
docs: /* ------------------------------------------------------------