Question

我正在使用Apache POI在数据库的帮助下创建一个excel文件。我尝试使用不同的代码进行大量搜索，但一次又一次地损坏了Excel工作表。到目前为止，这是我正在使用的代码：

    public void  generateExcel(ResultSet rs, String excelFilename, String newDesc){

    try {
        Workbook wb = new XSSFWorkbook();
        Cell c = null;
        //Cell style for header row
        CellStyle cs = wb.createCellStyle();
        cs.setFillForegroundColor(IndexedColors.LIME.getIndex());
        cs.setFillPattern(XSSFCellStyle.SOLID_FOREGROUND);
        Font f = wb.createFont();
        f.setBoldweight(Font.BOLDWEIGHT_BOLD);
        f.setFontHeightInPoints((short) 12);
        cs.setFont(f);

        //New Sheet
        Sheet sheet1 = null;
        sheet1 = wb.createSheet(newDesc);


        ResultSetMetaData metaData = rs.getMetaData();
        int colCount = metaData.getColumnCount();

        //Create Hash Map of Field Definitions
        LinkedHashMap<Integer, MyTableInfo> hashMap = new LinkedHashMap<Integer, MyTableInfo>(colCount);

        for (int i = 0; i < colCount; i++) {
            MyTableInfo db2TableInfo = new MyTableInfo(); 
            db2TableInfo.setFieldName(metaData.getColumnName(i + 1).trim());
            db2TableInfo.setFieldText(metaData.getColumnLabel(i + 1));
            db2TableInfo.setFieldSize(metaData.getPrecision(i + 1));
            db2TableInfo.setFieldDecimal(metaData.getScale(i + 1));
            db2TableInfo.setFieldType(metaData.getColumnType(i + 1));
            db2TableInfo.setCellStyle(getCellAttributes(wb, c, db2TableInfo));
            hashMap.put(i, db2TableInfo);
        }

        // Row and column indexes
        int idx = 0;
        int idy = 0;

        // Generate column headings
        Row row = sheet1.createRow(idx);
        MyTableInfo db2TableInfo = new MyTableInfo();

        Iterator<Integer> iterator = hashMap.keySet().iterator();
        while (iterator.hasNext()) {
            Integer key = (Integer) iterator.next();
            db2TableInfo = hashMap.get(key); 
            c = row.createCell(idy);
            c.setCellValue(db2TableInfo.getFieldText());
            c.setCellStyle(cs);
            if(db2TableInfo.getFieldSize() > db2TableInfo.getFieldText().trim().length()){
                sheet1.setColumnWidth(idy, (db2TableInfo.getFieldSize()* 500));
            }
            else {
                sheet1.setColumnWidth(idy, (db2TableInfo.getFieldText().trim().length() * 500));
            }
            idy++;
        }

        while (rs.next()) {

            idx++;
            row = sheet1.createRow(idx);
            System.out.println(idx);
            for (int i = 0; i < colCount; i++) {

                c = row.createCell(i);
                db2TableInfo = hashMap.get(i);

                switch (db2TableInfo.getFieldType()) {
                case 1:
                    c.setCellValue(rs.getString(i+1));
                    break;
                case 2:
                    c.setCellValue(rs.getDouble(i+1));
                    break;
                case 3:
                    c.setCellValue(rs.getDouble(i+1));
                    break;
                default:
                    c.setCellValue(rs.getString(i+1));
                    break;
                }
                c.setCellStyle(db2TableInfo.getCellStyle());
            }

        }

        rs.close();


        FileOutputStream fileOut = new FileOutputStream(excelFilename);

        wb.write(fileOut);
        fileOut.close();

    }
    catch (Exception e) {
        System.out.println(e);
    }

}


private static CellStyle getCellAttributes (Workbook wb, Cell c, MyTableInfo db2TableInfo){

    CellStyle cs= wb.createCellStyle();
    DataFormat df = wb.createDataFormat();
    Font f = wb.createFont();

    switch (db2TableInfo.getFieldDecimal()) {
    case 1:
        cs.setDataFormat(df.getFormat("#,##0.0"));
        break;
    case 2:
        cs.setDataFormat(df.getFormat("#,##0.00"));
        break;
    case 3:
        cs.setDataFormat(df.getFormat("#,##0.000"));
        break;
    case 4:
        cs.setDataFormat(df.getFormat("#,##0.0000"));
        break;
    case 5:
        cs.setDataFormat(df.getFormat("#,##0.00000"));
        break;
    default:
        break;
    }

    cs.setFont(f);

    return cs;

}

我收到以下消息：

"Excel cannot open the file "filename" because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file."

我以前曾经使用JXL生成excel文件，但最近它也开始为我提供同样的东西，因此我选择切换到Apache POI。

谢谢。

Answer 1

您的HttpServletResponse是否已正确设置？您正在使用什么文件扩展名？

尝试一下：

ServletOutputStream os = response.getOutputStream();
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-Disposition", "attachment; filename=\"example.xls\"");

workbook = getWorkbook(....)

workbook.write(os);
workbook.close();
os.flush();

response.flushBuffer();

其中“响应”是来自控制器方法的HttpServletResponse

Answer 2

当生成的Excel工作表没有要显示的数据时，出现此错误。请检查resultSet是否具有必需的数据。或者，您可以使用以下代码段在生成的excel中显示错误消息

if(rs.size()==0) {
                if (null != format && !format.equalsIgnoreCase("")
                        && format.equalsIgnoreCase("xlsx")) {
                    Row row = sheet.createRow(0);
                    Cell cell = row.createCell(0);
                    cell.setCellValue("There is no data to display");
                    excelWriterClose(new_workbook,out);

Apache POI生成损坏的Excel文件

2 个答案: