code: public void actionShow() throws Exception {
  
          // try to load the historical resource
          if (CmsStringUtil.isNotEmpty(getParamVersion())) {
              showHistoricVersion();
          } else {
              String resourceStr = getParamResource();
              // trying to read the resource
              CmsResource resource = readResource(resourceStr);
              if (isDeleted(resource)) {
                  // resource has been deleted in offline project
                  throw new CmsVfsResourceNotFoundException(Messages.get().container(
                      Messages.ERR_RESOURCE_DELETED_2,
                      resourceStr,
                      getCms().getRequestContext().getCurrentProject().getName()));
              }
  
              // check for release / expiration time window
              autoTimeWarp(resource);
  
              // code for display resource after all tests for displayability (exists, not deleted)
              //            if (CmsResourceTypeXmlContainerPage.isContainerPage(resource)) {
              //                // if we have a container page look for the first sitemap entry
              //                // and use that to display the container page
              //                List<CmsInternalSitemapEntry> entries = OpenCms.getSitemapManager().getEntriesForStructureId(
              //                    getJsp().getCmsObject(),
              //                    resource.getStructureId());
              //                if (!entries.isEmpty()) {
              //                    CmsInternalSitemapEntry entry = entries.get(0);
              //                    resourceStr = entry.getRootPath();
              //                }
              //            }
              if (OpenCms.getSiteManager().isSharedFolder(getCms().getRequestContext().getSiteRoot())) {
                  if (!OpenCms.getSiteManager().startsWithShared(resourceStr)) {
                      resourceStr = CmsStringUtil.joinPaths(OpenCms.getSiteManager().getSharedFolder(), resourceStr);
                  }
              }
              String url = getJsp().link(resourceStr);
              // if in online project
              if ((url.indexOf("://") < 0) && getCms().getRequestContext().getCurrentProject().isOnlineProject()) {
                  url = prependSiteRoot(url);
              }
              getJsp().getResponse().sendRedirect(url);
          }
      }
docs: Redirects to the specified file or shows an historical resource.<p>
  
  @throws Exception if redirection fails