我有一個存儲 Excel 工作簿的類：private Map<String, Workbook> workbooks = new HashMap();public Workbook createWorkbook(String name)  {    Workbook workbook = new XSSFWorkbook();    workbooks.put(name, workbook);    return workbook;}以及寫入具有指定名稱的工作簿的方法：public void write(List<ExcelData> data, String workbookName) {   Workbook workbook = workbooks.get(workbookName);   CreationHelper createHelper = workbook.getCreationHelper();   ... write stuff   FileOutputStream fileOut = new FileOutputStream(workbookName + ".xlsx");   workbook.write(fileOut);   fileOut.close();   workbook.close();}但是，當我嘗試為同一個工作簿調用方法write兩次時：testExcel.write(data, "Default");testExcel.write(data1, "Default");我得到Exception in thread "main" java.io.IOException: Cannot write data, document seems to have been closed already錯誤。我知道我可以像這樣打開現有的 Excel 工作簿：FileInputStream inputStream = new FileInputStream(new File(excelFilePath));Workbook workbook = WorkbookFactory.create(inputStream);但我想知道是否有辦法通過存儲Workbook變量來繞過它。有什么內在機制在起作用？workbook.write()調用后變量是否失效？