使用POI将不同的数据类型写入Excel

Question

我正在尝试将数据从数据库导出到Excel。 我已导出数据，当前正在将数据存储在ArrayList中（可以更改）。 我已经能够将数据导出到excel，但是所有值都被导出为字符串，我需要它们保持其数据类型，即货币/数字。

我正在使用Apache POI，并且很难将字段的数据类型设置为String以外的任何其他类型。 我想念什么吗？ 有人可以建议我做一个更好的方法吗？ 任何帮助，将不胜感激。

public static void importDataToExcel(String sheetName, ArrayList header, ArrayList data, File xlsFilename, int sheetNumber)
        throws HPSFException, FileNotFoundException, IOException {

    POIFSFileSystem fs = new POIFSFileSystem();
    HSSFWorkbook wb = new HSSFWorkbook(new FileInputStream(xlsFilename));
    HSSFSheet sheet = wb.createSheet(sheetName);

    int rowIdx = 0;
    short cellIdx = 0;

    // Header
    HSSFRow hssfHeader = sheet.createRow(rowIdx);
    HSSFCellStyle cellStyle = wb.createCellStyle();
    cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    for (Iterator cells = header.iterator(); cells.hasNext();) {
        HSSFCell hssfCell = hssfHeader.createCell(cellIdx++);
        hssfCell.setCellStyle(cellStyle);
        hssfCell.setCellValue((String) cells.next());
    }
    // Data

    rowIdx = 1;
    for (Iterator rows = data.iterator(); rows.hasNext();) {
        ArrayList row = (ArrayList) rows.next();
        HSSFRow hssfRow = (HSSFRow) sheet.createRow(rowIdx++);
        cellIdx = 0;
        for (Iterator cells = row.iterator(); cells.hasNext();) {
            HSSFCell hssfCell = hssfRow.createCell(cellIdx++);
            hssfCell.setCellValue((String) cells.next());
        }
    }
    Logfile.log("sheetNumber = " + sheetNumber);
    wb.setSheetName(sheetNumber, sheetName);
    try {
        FileOutputStream out = new FileOutputStream(xlsFilename);
        wb.write(out);
        out.close();
    } catch (IOException e) {
        throw new HPSFException(e.getMessage());
    }

}

Answer 1

在进行转换之前，您需要检查单元格值的类：

public static void importDataToExcel(String sheetName, List<String> headers, List<List<Object>> data, File xlsFilename, int sheetNumber)
        throws HPSFException, FileNotFoundException, IOException {

    POIFSFileSystem fs = new POIFSFileSystem();
    Workbook wb;
    try {
        wb = WorkbookFactory.create(new FileInputStream(xlsFilename));
    } catch (InvalidFormatException ex) {
        throw new IOException("Invalid workbook format");
    }
    Sheet sheet = wb.createSheet(sheetName);

    int rowIdx = 0;
    int cellIdx = 0;

    // Header
    Row hssfHeader = sheet.createRow(rowIdx);
    CellStyle cellStyle = wb.createCellStyle();
    cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    for (final String header : headers) {
        Cell hssfCell = hssfHeader.createCell(cellIdx++);
        hssfCell.setCellStyle(cellStyle);
        hssfCell.setCellValue(header);
    }
    // Data

    rowIdx = 1;
    for (final List<Object> row : data) {
        Row hssfRow = sheet.createRow(rowIdx++);
        cellIdx = 0;
        for (Object value : row) {
            Cell hssfCell = hssfRow.createCell(cellIdx++);
            if (value instanceof String) {
                hssfCell.setCellValue((String) value);
            } else if (value instanceof Number) {
                hssfCell.setCellValue(((Number) value).doubleValue());
            } else {
                throw new RuntimeException("Cell value of invalid type " + value);
            }
        }
    }
    wb.setSheetName(sheetNumber, sheetName);
    try {
        FileOutputStream out = new FileOutputStream(xlsFilename);
        wb.write(out);
        out.close();
    } catch (IOException e) {
        throw new HPSFException(e.getMessage());
    }
}

我还添加了泛型-这使代码更具可读性。 另外，您还需要避免使用实际的class ，并尽可能使用interface ，例如List而不是ArrayList和Row而不是HSSFRow 。