private void setCellGroudColor(Sheet sheet, Cell cell, short colorValue)
    {
        HSSFCellStyle style = (HSSFCellStyle) sheet.getWorkbook()
                .createCellStyle();
        style.setBorderTop(HSSFCellStyle.BORDER_THIN);
        style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
        style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
        style.setBorderRight(HSSFCellStyle.BORDER_THIN);
        style.setTopBorderColor(HSSFColor.BLACK.index);
        style.setBottomBorderColor(HSSFColor.BLACK.index);
        style.setLeftBorderColor(HSSFColor.BLACK.index);
        style.setRightBorderColor(HSSFColor.BLACK.index);
        style.setFillForegroundColor(colorValue);
        style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
        if (cell.getCellType() == HSSFCell.CELL_TYPE_NUMERIC
                && HSSFDateUtil.isCellDateFormatted(cell))
        {
            style.setDataFormat(sheet.getWorkbook().createDataFormat()
                    .getFormat("yyyy/m/d"));
            cell.setCellStyle(style);
            Date date = cell.getDateCellValue();
            cell.setCellValue(date);
        }
        else
        {
            cell.setCellStyle(style);
        }
    }
我在for循环里多次调用这个方法,导出的excel里,为什么只有第一行的有背景色,而其他的没有呢?