private void write(String PATH) {
    try {
        InputStream inp = new FileInputStream(PATH + "\workbook.xlsx");
        Workbook wb = null;
        try {
            wb = WorkbookFactory.create(inp);
        } catch (EncryptedDocumentException | InvalidFormatException e) {
            e.printStackTrace();
        }
        Sheet sheet = wb.getSheetAt(1);
        int rowCounter = 0;
        Cell[] mas = new Cell[500];
        List<Cell> cellList = new LinkedList<Cell>();
        for (int i = 0; i < getFinishFile().size(); i++) {
            Row row = sheet.createRow(rowCounter++);
            for (int j = 0; i < mas.length; i++) {
                mas[i] = row.createCell(j);
                cellList.add(mas[i]);
            }
            int j = 0;
            for (Cell c : cellList) {
                c.setCellValue(getFinishFile().get(i)[j]);
                j++;
            }
        }
        FileOutputStream fileOut = new FileOutputStream(PATH + "\workbook.xlsx");
        wb.write(fileOut);
        fileOut.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

private static final LENGTH = 500

private void write(String PATH) {
    try {
        InputStream inp = new FileInputStream(PATH + "\workbook.xlsx");
        Workbook wb = WorkbookFactory.create(inp);
        Sheet sheet = wb.getSheetAt(1);
        for (int i = 0; i < getFinishFile().size(); i++) {
            Row row = sheet.createRow(i);
            for (int j = 0; j < LENGTH; j++) {
              row.createCell().setCellValue(getFinishFile().get(i)[j])
            }
        }
        FileOutputStream fileOut = new FileOutputStream(PATH + "\workbook.xlsx");
        wb.write(fileOut);
        fileOut.close();
    } catch (EncryptedDocumentException | IOException e | InvalidFormatException e) {
        e.printStackTrace();
    }
}