JSF-在Apache POI中使用HSSFFont为JSF中的excel表格设置全局字体类型

我可以选择将数据表导出到Excel工作表。
我正在尝试将工作表中所有单元格的字体类型设置为“ Calibri”。
但是下面的代码仅为页眉分配字体类型，而不为其余单元格分配字体类型。
如何为工作表中的所有单元格全局设置字体类型？

  public void exportToXLS(Object document) {

        HSSFWorkbook wb = (HSSFWorkbook) document;
        HSSFSheet sheet = wb.getSheetAt(0);
        wb.setSheetName(0, "report_lists"); // set sheet name
        sheet.shiftRows(0, sheet.getLastRowNum(), 4); // shifting the rows to
        HSSFRow header = sheet.getRow(4);
        header.getCell(1).setCellValue("Test Group");
        header.getCell(2).setCellValue("Category");

        HSSFRow firstrow = sheet.getRow(0);
        firstrow.createCell(0).setCellValue("Actuals");

        SimpleDateFormat sdf = new SimpleDateFormat(
                "EEE MMM d HH:mm:ss 'CDT'  yyyy ");
        Date date = new Date();
        sdf.setTimeZone(TimeZone.getTimeZone("GMT-5"));
        String reportDate = sdf.format(date);
        HSSFRow thirdrow = sheet.getRow(3);
        thirdrow.createCell(0).setCellValue(reportDate);

        HSSFCellStyle cellStyle = wb.createCellStyle();
        cellStyle.setFillForegroundColor(HSSFColor.YELLOW.index);
        cellStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
        HSSFFont fontHeader = (HSSFFont) wb.createFont();
        fontHeader.setFontName("Calibri");
        cellStyle.setFont(fontHeader);
        System.out.println(" header.getPhysicalNumberOfCells();::::"
                + header.getPhysicalNumberOfCells());

        //only for changing font for header
        for (int i = 0; i < header.getPhysicalNumberOfCells(); i++) {
            HSSFCell cell = header.getCell(i);
            cell.setCellStyle(cellStyle);
            // sheet.setDefaultColumnStyle(i, cellStyle);

        }
        System.out.println("sheet.getLastRowNum():::" + sheet.getLastRowNum());
        for (int j = 1; j < sheet.getPhysicalNumberOfRows(); j++) {
            HSSFRow row = sheet.getRow(j);
            if (row != null) {
                System.out.println(" j>>>" + j);
                // you can add sysout or debug here to check if all row passed
                // successfully
                for (int i = 0; i < row.getPhysicalNumberOfCells(); i++) {
                    HSSFCell cell = row.getCell(i);
                    if (cell != null) {
                        System.out.println(" i++" + i);
                        // you can add sysout or debug here to check if all cell
                        // passed successfully
                        HSSFCell celll = header.getCell(i);
                        celll.setCellStyle(cellStyle);
                    }
                }
            }
        }


    }

这是excel的屏幕截图：