POI读取excel的时候，空值不读取的问题，求大神指导

 private void loadUserInfo(String str2,String filename2) {
        String uploadFileFileName=str2+filename2;
        Logger logger = LoggerUtil.getLoggerByName(str2);
        // 读取刚才上传文件，确保路径相同
        // String uploadFileFileName=str1+filename1;
        System.out.println("11212" + uploadFileFileName);
        // System.out.println(str1+"+"+filename1);
        String directory = "/upload";
        String targetDirectory = ServletActionContext.getServletContext()
                .getRealPath(directory);
        File target = new File(targetDirectory, uploadFileFileName);
        Workbook wb = null;
        try {
            FileInputStream fi = new FileInputStream(target);
            if (uploadFileFileName.toLowerCase().endsWith("xls")) {
                wb = new HSSFWorkbook(fi);
            } else if (uploadFileFileName.toLowerCase().endsWith("xlsx")) {
                wb = new XSSFWorkbook(fi);
            }

            Sheet sheet = wb.getSheetAt(0);

            int rowNum = sheet.getLastRowNum() + 1;
            lists = new ArrayList<Muju>();
            // i 从1开始表示第一行为标题 不包含在数据中
            Muju muju = null;
            for (int i = 1; i < rowNum; i++) {
                muju = new Muju();
                Row row = sheet.getRow(i);
                int cellNum = row.getLastCellNum();
                for (int j = 0; j < cellNum; j++) {
                    Cell cell = row.getCell(j);
                    String cellValue = null;

                    switch (cell.getCellType()) { // 判断excel单元格内容的格式，并对其进行转换，以便插入数据库
                    case 0:
                        String s = String.valueOf(cell.getNumericCellValue());
                        if (s.endsWith(".0")) {
                            cellValue = String.valueOf((int) cell
                                    .getNumericCellValue());
                        } else
                            cellValue = String.valueOf(cell
                                    .getNumericCellValue());
                        break;
                    case 1:
                        cellValue = cell.getStringCellValue();System.out.println("kanka22n="+cellValue);
                        break;
                    case 2:
                        cellValue = String.valueOf(cell.getDateCellValue());
                        break;
                    case 3:
                        System.out.println("asasas");
                        cellValue = "";
                        break;
                    case 4:
                        cellValue = String.valueOf(cell.getBooleanCellValue());
                        break;
                    case 5:
                        cellValue = String.valueOf(cell.getErrorCellValue());
                        break;
                    }
                    System.out.println("kanka33n="+cellValue);
                    switch (j) {// 通过列数来判断对应插如的字段

                    case 0:
                        muju.setVendor(cellValue);
                        break;
                    case 1:
                        muju.setItem(cellValue);
                        break;
                    case 2:
                        muju.setKmcishu(Integer.parseInt(cellValue));
                        break;
                    case 3:
                        muju.setSycishu(Integer.parseInt(cellValue));
                        break;
                    case 4:
                        muju.setXianelv(Double.parseDouble(cellValue));
                        break;
                    case 5:
                        muju.setLjcishu(Integer.parseInt(cellValue));
                        break;
                    case 6:
                        muju.setFqcishu(Integer.parseInt(cellValue));
                        break;
                    }
                }
                lists.add(muju);

            }
            Muju muju2 = null;
            for (int f = 0; f < lists.size(); f++) {
                muju2 = lists.get(f);
                System.out.println(lists);
                System.out.println(lists.get(f).getVendor());
                System.out.println(lists.get(f).getItem());
                System.out.println(lists.get(f).getKmcishu());
                System.out.println(lists.get(f).getSycishu());
                System.out.println(lists.get(f).getXianelv());
                System.out.println(lists.get(f).getLjcishu());
                System.out.println(lists.get(f).getFqcishu());

                Mujudao mjd = new Mujudao();
                Muju mj = mjd.itemandvendor(lists.get(f).getVendor(), lists.get(f).getItem());
                System.out.println(mj);
                if (mj == null) {

                    logger.debug(changliang.shibai1(f+1, muju2.getVendor(), muju2.getItem())); 
                } else {
                    int a = mjd.updateitemandvendor(muju2.getVendor(),
                            muju2.getItem(), muju2.getKmcishu(), 
                            muju2.getSycishu(), muju2.getXianelv(),
                            muju2.getLjcishu(), muju2.getFqcishu());
                    if(a==0){
                        logger.debug(changliang.shibai2(f+1));
                    }
                    else
                        logger.debug(changliang.chenggong(f+1));
                }

            }

        } catch (IOException e) {
            e.printStackTrace();
        }

    }

如果图片是上图这样，就会出错，空值以后的数据全都不会被导入（下面的代码都不执行了，也没出任何异常）
如果图片是下图这样，却能正常导入

但是，无论如何，我中间的，取空值时候的代码
System.out.println("asasas");都不会执行

求教大神这是怎么回事

Integer.parseInt(cellValue)；你要先判断cellValue是空值 还是空字符串，如果是其中一种则设置为cellValue = “0”，即可，不然会出错的