code: public File getFile()
          throws IOException
      {
          // Try the permission hack
          if (checkConnection())
          {
              Permission perm = _connection.getPermission();
              if (perm instanceof java.io.FilePermission)
                  return new File(perm.getName());
          }
  
          // Try the URL file arg
          try {return new File(_url.getFile());}
          catch(Exception e) {LogSupport.ignore(log,e);}
  
          // Don't know the file
          return null;    
      }
docs: Returns an File representing the given resource or NULL if this
  is not possible.