Java apache poi 将excel转换为json

ExcelToJson转换器

public JsonNode excelToJson(File excel) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
            // hold the excel data sheet wise
            ObjectNode excelData = mapper.createObjectNode();
            FileInputStream fis = null;
            Workbook workbook = null;
            try {
                // Creating file input stream
                fis = new FileInputStream(excel);

                String filename = excel.getName().toLowerCase();
                if (filename.endsWith(".xls") || filename.endsWith(".xlsx")) {
                    // creating workbook object based on excel file format
                    if (filename.endsWith(".xls")) {
                        workbook = new HSSFWorkbook(fis);
                    } else {
                        workbook = new XSSFWorkbook(fis);
                    }

                    // Reading each sheet one by one
                    for (int i = 0; i < workbook.getNumberOfSheets(); i++) {
                        Sheet sheet = workbook.getSheetAt(i);
                        String sheetName = sheet.getSheetName();

                        List<String> headers = new ArrayList<String>();
                        ArrayNode sheetData = mapper.createArrayNode();
                        // Reading each row of the sheet
                        for (int j = 0; j <= sheet.getLastRowNum(); j++) {
                            Row row = sheet.getRow(j);
                            if (j == 0) {
                                // reading sheet header's name
                                for (int k = 0; k < row.getLastCellNum(); k++) {
                                    headers.add(row.getCell(k).getStringCellValue());
                                }
                            } else {
                                // reading work sheet data
                                ObjectNode rowData = mapper.createObjectNode();
                                for (int k = 0; k < headers.size(); k++) {
                                    Cell cell = row.getCell(k);
                                    String headerName = headers.get(k);
                                    if (cell != null) {
                                        switch (cell.getCellType()) {
                                            case FORMULA:
                                                rowData.put(headerName, cell.getCellFormula());
                                                break;
                                            case BOOLEAN:
                                                rowData.put(headerName, cell.getBooleanCellValue());
                                                break;
                                            case NUMERIC:
                                                rowData.put(headerName, cell.getNumericCellValue());
                                                break;
                                            case BLANK:
                                                rowData.put(headerName, "");
                                                break;
                                            default:
                                                rowData.put(headerName, cell.getStringCellValue());
                                                break;
                                        }
                                    } else {
                                        rowData.put(headerName, "");
                                    }
                                }
                                sheetData.add(rowData);
                            }
                        }
                        excelData.set(sheetName, sheetData);
                    }
                    return excelData;
                } else {
                    throw new IllegalArgumentException("File format not supported.");
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if (workbook != null) {
                    try {
                        workbook.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                if (fis != null) {
                    try {
                        fis.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }

            }
            return null;
    }

该方法工作正常，但在输出时会生成一个数组，然后需要将其写入数据库.此数组形成一个对象，数据无法写入数据库.