Eclipse JavaDoc自动生成@return

Question

我认为$ {tags}可以通过方法自动生成@param @return @throws。但是我的eclipse没有生成@ return.What是错的？ tags label

/**
 * 
 * @param einvoiceUploadPDF
 * @return
 */
public Map<String, String> buildUploadParamMap(EinvoiceUploadPDF einvoiceUploadPDF) {
  Gson gson = new Gson();
  Map<String, String> paramsMap = new HashMap<String, String>();
  paramsMap.put("requestdatas", gson.toJson(einvoiceUploadPDF));
  return paramsMap;
}