Java中Excel文件导出

利用公司所学作为简单示例：
（简单实现逻辑为将文件生成在项目中，当用户下载后将文件重新删除）
以下程序为Java中Excel的属性配置，参数配置，数据配置等

    public IResData exportGzrwqkaxmtjData(final IReqData req) throws SwordBaseCheckedException, IOException {
        final IResData res = new SwordRes();
        //获取窗体的值，引入实体类
        final Map<String, String> gzrwqkaxmtjForm = req.getFormData("gzrwqkaxmtjForm");
        //获取所需要导入Excel表中的数据
        final List<Map<String, Object>> information = (List<Map<String, Object>>) SwordServiceUtils.callService("DSJYPT.XMGL.GZRW.QKAXMTJ", gzrwqkaxmtjForm);
        //定义Excel中表格的数据格式
        final List<Map<String, Object>> excelList = new ArrayList<Map<String, Object>>();
        //定义Excel的相关信息
        final Map<String, Object> excel = new HashMap<String, Object>();
        excel.put("title", "标题名称");
        excel.put("sheet", "表名");
        //定义列名和列值
        final String[] columns = {"字段名"};
        final String[] fields = {"字段值"};
        excel.put("columns", columns);
        excel.put("fields", fields);
        excel.put("data", information);
        excelList.add(excel);
        final HSSFWorkbook workbook = new HSSFWorkbook();
        //处理数据，完成整体Excel的生成和设置
        this.exportExcel(workbook, excelList);
        //下面的代码功能为将文件生成放在项目中
        final String path = this.getHttpReq().getSession().getServletContext().getRealPath("路径");
        final String uuid = UUID.randomUUID().toString().replace("-", "");
        final FileOutputStream fos = new FileOutputStream(path + "/" + uuid + ".xls");
        workbook.write(fos);
        fos.flush();
        fos.close();
        res.addAttr("fileName", uuid);
        return res;
    }

以下代码为配置Excel的表格样式，数据填入等处理操作

        public HSSFWorkbook exportExcel(HSSFWorkbook workbook, List<Map<String, Object>> excelList) {
        for (Map<String, Object> excel : excelList) {
            int k = 0;
            final String sheetName = (String) excel.get("sheet");
            HSSFSheet sheet = null;
            if (GyUtils.isNull(sheetName)) {
                sheet = workbook.createSheet();
            } else {
                try {
                    sheet = workbook.createSheet(sheetName);
                } catch (Exception e) {
                    sheet = workbook.createSheet();
                }
            }
            final String title = (String) excel.get("title");
            final String[] columns = (String[]) excel.get("columns");
            //开始填入数据
            final String[] fields = (String[]) excel.get("fields");
            //设置标题
            if (!GyUtils.isNull(title)) {
                final HSSFCellStyle titleStyle = workbook.createCellStyle();
                final HSSFFont titleFont = workbook.createFont();
                titleFont.setFontName("黑体");
                titleFont.setFontHeightInPoints((short) 14);
                titleFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
                titleStyle.setFont(titleFont);
                // 设置单元格格式居中
                titleStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
                titleStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
                final int length = fields.length;
                sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, length - 1 >= 0 ? length - 1 : 0));
                final HSSFRow rowTitle = sheet.createRow(k);
                rowTitle.setHeight((short) (14 * 40));
                final HSSFCell cell = rowTitle.createCell(0);
                cell.setCellValue(title);
                cell.setCellStyle(titleStyle);
                k++;
            }
            final HSSFCellStyle cellStyle = workbook.createCellStyle();
            // 设置单元格格式居中
            cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
            //设置标题
            if (!GyUtils.isNull(columns)) {
                final HSSFRow hssfRow = sheet.createRow(k);
                k++;
                for (int i = 0; i < columns.length; i++) {
                    final HSSFCell headCell = hssfRow.createCell(i);
                    headCell.setCellValue(columns[i]);
                    headCell.setCellStyle(cellStyle);
                    sheet.setColumnWidth(i, 80 * 80);
                }
            }
            //添加数据
            final List<?> listData = (List<?>) excel.get("data");
            for (Object vo : listData) {
                final HSSFRow row = sheet.createRow(k);
                k++;
                for (int j = 0; j < fields.length; j++) {
                    final HSSFCell headCell = row.createCell(j);
                    String value = "";
                    try {
                        value = GyUtils.getValueByKey(vo, fields[j]);
                    } catch (SwordBaseCheckedException e) {
                        value = "";
                    }
                    headCell.setCellValue(value);
                    headCell.setCellStyle(cellStyle);
                }
            }
        }
        return workbook;
    }

以下为文件的下载事件

    public IResData downLoadFile(final IReqData req) throws SwordBaseCheckedException, IOException {
        final IResData res = new SwordRes();
        //获取到文件名
        final String fileName = (String) req.getAttr("fileName");
        //到指定路径下获取文件
        final File file = new File(this.getHttpReq().getSession().getServletContext().getRealPath("路径") + "/" + fileName + ".xls");
        //下载文件
        this.downLoad(file, "文件名.xls");
        //删除生成的文件
        file.delete();
        return res;
    }

文章中所需Jar包可在网络上自行下载，本文不提供jar包的相关数据。整体流程为上面所叙述的，若代码看不懂，可根据注解提供参考思路。