/**
     * @param wb excel
     * @return sheet集合<row集合<cell集合，全转为String类型>>
     */
    public static List<List<List<String>>> getExcelData(XSSFWorkbook wb){
        int numSheets = wb.getNumberOfSheets();
        List<List<List<String>>> sheets = new ArrayList<>();
        //sheet
        for(int i=0;i<numSheets;i++){
            XSSFSheet sheet = wb.getSheetAt(i);
            System.out.println(sheet.getSheetName());
            int numRows = sheet.getLastRowNum();
            List<List<String>> rows = new ArrayList<>();
            //row
            for (int j=0;j<numRows;j++){
                XSSFRow row = sheet.getRow(j);
                if (row==null){
                    break;
                }
                int numCells = row.getLastCellNum();
                List<String> cells = new ArrayList<>();
                //cell
                for (int k=0;k<numCells;k++){
                   cells.add(getValue(k,row));
                }
                rows.add(cells);
            }
            sheets.add(rows);
        }
        return sheets;
    }
   /**
     * 获取指定位置的数据值，全转为string
     * @param rowNum 所属行， 第一行为0
     * @param colNum 所诉列， 第一列为0
     * @return 值
     */
    public static String getValue(int rowNum, int colNum, XSSFSheet sheet){
        XSSFRow row = sheet.getRow(rowNum);
        return getValue(colNum, row);
    }

    public static String getValue(int colNum, XSSFRow row){
        XSSFCell cell = row.getCell(colNum);
        if (cell==null){
            return "";
        }
        String cellValue = "";
        CellType cellTypeEnum = cell.getCellTypeEnum();
        try {
            DecimalFormat df = new DecimalFormat("0.00");
            if (cell.getCellTypeEnum() == CellType.NUMERIC) {
                if (HSSFDateUtil.isCellDateFormatted(cell)) {
                    cellValue = DateFormatUtils.format(cell.getDateCellValue(), "yyyy-MM-dd");
                } else {
                    NumberFormat nf = NumberFormat.getInstance();
                    cellValue = String.valueOf(nf.format(cell.getNumericCellValue())).replace(",", "");
                }
            } else if (cell.getCellTypeEnum() == CellType.STRING) {
                cellValue = String.valueOf(cell.getStringCellValue());
            } else if (cell.getCellTypeEnum() == CellType.BOOLEAN) {
                cellValue = String.valueOf(cell.getBooleanCellValue());
            } else if (cell.getCellTypeEnum() == CellType.ERROR) {
                cellValue = "错误类型";
            } else if (cell.getCellTypeEnum() == CellType.FORMULA) {//公式类型
                cellValue = df.format(cell.getNumericCellValue());//将公式类型的值转成保留两位小数的数字
//            cellValue = String.valueOf(cell.getArrayFormulaRange().getNumberOfCells());
            } else {
                cellValue = "";
            }
        }catch (Exception e){
            logger.error(e.getMessage(),e);
            cellValue = "-9999999999";
        }
        return cellValue;
    }