/**
  * Create an ExternalFileHandle to represent an external URL. Synapse will attempt to generate a
  * preview for any external URL that can be publicly read. The resulting preview file will be
  * stored in Synapse and represented with a PrevewFileHandle. The creator of the
  * ExternalFileHandle will be listed as the creator of the preview.
  *
  * @param userId
  * @param fileHandle The ExternalFileHandle to create
  * @return
  * @throws DatastoreException
  * @throws NotFoundException
  */
 @ResponseStatus(HttpStatus.OK)
 @RequestMapping(value = "/externalFileHandle", method = RequestMethod.POST)
 public @ResponseBody ExternalFileHandle createExternalFileHandle(
     @RequestParam(value = AuthorizationConstants.USER_ID_PARAM) String userId,
     @RequestBody ExternalFileHandle fileHandle)
     throws DatastoreException, NotFoundException {
   // Pass it along
   return fileService.createExternalFileHandle(userId, fileHandle);
 }