protected Excel_File(String fp) {
   try {
     file_path = fp;
     FileType = new File_Type_Check(fp);
     if (FileType.getFileType() == 1) {
       excel_xls = new Excel_xls(fp);
       wb_xls = excel_xls.getWorkBook();
     } else if (FileType.getFileType() == 2) {
       excel_xlsx = new Excel_xlsx(fp);
       wb_xlsx = excel_xlsx.getWorkBook();
     }
   } catch (Exception e1) {
     System.out.println("Initialize Excel_File failed");
     e1.printStackTrace();
   }
 }