使用POI读取Excel报异常java.lang.ClassNotFoundException

这是读取Excel的代码
  
    InputStream is = null;
                String name = null;
                String sex = null;
                String phone = null;
                    try {
                        is = getAssets().open("test.xlsx");
                        Workbook workbook = WorkbookFactory.create(is);
                        Sheet sheet = workbook.getSheetAt(0);
                        int rowCount = sheet.getPhysicalNumberOfRows();
                        for (int r = 0; r < rowCount; r++) {
                            Row row = sheet.getRow(r);
                            int cellCount = row.getPhysicalNumberOfCells(); // 获取总列数
                            for (int c = 0; c < cellCount; c++) {
                                Cell cell = row.getCell(c);
                                int cellType = cell.getCellType();
                                String cellValue = null;
                                switch (cellType) {
                                    case Cell.CELL_TYPE_STRING: // 文本
                                        cellValue = cell.getStringCellValue();
                                        if (cellValue.equals("男")||cellValue.equals("女")) {
                                            sex=cellValue;
                                        }
                                        else {
                                            name=cellValue;
                                        }
                                        break;
                                    case Cell.CELL_TYPE_NUMERIC:
                                        DecimalFormat df = new DecimalFormat("0");
                                        cellValue= df.format(cell.getNumericCellValue());
                                        phone=cellValue;
                                        break;
                                    default:
                                }
                            }
                            values.put("name", name);
                            values.put("sex", sex);
                            values.put("phone", phone);
                            service.addPerson(values);
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }这是导入的jar包困扰很久了 ，跪求 大神指点！！