POI-3.17操作excel（读）

public static List<Map<String, Object>> readExcel1(String filepath, String filename, int startrow, int startcol, int sheetnum) {
        List<Object> varList = new ArrayList<Object>();
        try {
            File target = new File(filepath, filename);
            FileInputStream fi = new FileInputStream(target);
            HSSFWorkbook wb = new HSSFWorkbook(fi);
            HSSFSheet sheet = wb.getSheetAt(sheetnum);                    //sheet 从0开始
            int rowNum = sheet.getLastRowNum() + 1;                    //取得最后一行的行号
            for (int i = startrow; i < rowNum; i++) {                    //行循环开始
                Map<String, Object> varpd = new HashMap<>();
                HSSFRow row = sheet.getRow(i);                            //行
                int cellNum = row.getLastCellNum();                    //每行的最后一个单元格位置
                for (int j = startcol; j < cellNum; j++) {                //列循环开始
                    HSSFCell cell = row.getCell(Short.parseShort(j + ""));
                    String cellValue = null;
                    if (null != cell) {
                        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:
                                if (HSSFDateUtil.isCellDateFormatted(cell)) {// 判断是否是日期
                                    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
                                    cellValue = sdf.format(HSSFDateUtil.getJavaDate(cell.getNumericCellValue()));
                                    break;
                                } else {
                                    cellValue = String.valueOf((int) cell.getNumericCellValue());
                                    break;
                                }
                            case 1:
                                cellValue = cell.getStringCellValue();
                                break;
                            case 2:
                                cellValue = cell.getNumericCellValue() + "";
                                break;
                            case 3:
                                cellValue = "";
                                break;
                            case 4:
                                cellValue = String.valueOf(cell.getBooleanCellValue());
                                break;
                            case 5:
                                cellValue = String.valueOf(cell.getErrorCellValue());
                                break;
                        }
                    } else {
                        cellValue = "";
                    }
                    varpd.put("var" + j, cellValue);
                }
                varList.add(varpd);
            }
        } catch (Exception e) {
            System.out.println(e);
        }
        return varList;
    }