code: private Map<CmsExportname, String> computeVfsExportnames() {
  
          if (LOG.isDebugEnabled()) {
              LOG.debug(Messages.get().getBundle().key(Messages.LOG_UPDATE_EXPORTNAME_PROP_START_0));
          }
  
          CmsSiteManagerImpl sm = OpenCms.getSiteManager();
  
          List<CmsResource> resources;
          CmsObject cms = null;
          try {
              // this will always be in the root site
              cms = OpenCms.initCmsObject(OpenCms.getDefaultUsers().getUserExport());
              resources = cms.readResourcesWithProperty(CmsPropertyDefinition.PROPERTY_EXPORTNAME);
  
              synchronized (m_lockSetExportnames) {
                  Map<CmsExportname, String> exportnameResources = new HashMap<CmsExportname, String>();
                  for (int i = 0, n = resources.size(); i < n; i++) {
                      CmsResource res = resources.get(i);
                      try {
                          String foldername = res.getRootPath();
                          String exportname = cms.readPropertyObject(
                              foldername,
                              CmsPropertyDefinition.PROPERTY_EXPORTNAME,
                              false).getValue();
                          CmsSite site = sm.getSiteForRootPath(foldername);
                          if (exportname != null) {
                              if (exportname.charAt(exportname.length() - 1) != '/') {
                                  exportname = exportname + "/";
                              }
                              if (exportname.charAt(0) != '/') {
                                  exportname = "/" + exportname;
                              }
                              // export name has to be system-wide unique
                              // the folder name is a root path
                              exportnameResources.put(new CmsExportname(exportname, site), foldername);
                          }
                      } catch (CmsException e) {
                          // should never happen, folder will not be added
                          LOG.error(e.getLocalizedMessage(), e);
                      }
                  }
                  return Collections.unmodifiableMap(exportnameResources);
              }
          } catch (CmsException e) {
              // should never happen, no resources will be added at all
              LOG.error(e.getLocalizedMessage(), e);
              return Collections.emptyMap();
          }
      }
docs: Returns the map of vfs exportnames with exportname as key and the vfs folder path as value.<p>
  
  @return the map of vfs exportnames with exportname as key and the vfs folder path as value