code: public HSSFWorkbook toExcel(Collection<Object[]> datas, String propertyShowKeys) throws Exception {
      // 建立新HSSFWorkbook对象
      HSSFWorkbook wb = new HSSFWorkbook();
      return toExcel(wb, "export data", datas, propertyShowKeys);
    }
docs: <p>
  toExcel.
  </p>
  
  @param datas a {@link java.util.Collection} object.
  @param propertyShowKeys a {@link java.lang.String} object.
  @return a {@link org.apache.poi.hssf.usermodel.HSSFWorkbook} object.
  @throws java.lang.Exception if any.