poi创建excel示例

PoiExcelExample.java

public void exportProj(HttpServletResponse response) {
        HSSFWorkbook workbook = new HSSFWorkbook();
        final List<String> headers = new ArrayList<>();
        headers.add("列1");
        headers.add("列2");
        headers.add("列3");
        headers.add("列4");

        Map<Integer, JSONArray> map;
        for (Integer cityId : map.keySet()) {
            JSONArray projs = map.get(cityId);
            HSSFSheet sheet = workbook.createSheet(cityInfoMap.get(cityId).getCityName());
            int rowNum = 0;

            //设置标题行
            HSSFRow row = sheet.createRow(rowNum++);
            for (int i = 0; i < headers.size(); ++i) {
                HSSFCell cell = row.createCell(i, CellType.STRING);
                cell.setCellValue(headers.get(i));
            }

            //填充数据行
            for (Object proj : projs) {
                ProjToExport export = (ProjToExport)proj;
                row = sheet.createRow(rowNum++);
                List<String> values = new ArrayList<>(headers.size());
                values.add(export.getGroupId().toString());
                values.add(export.getProjName());
                values.add(export.getProjName())
                values.add(export.getTargetPhone());

                for (int i = 0; i < values.size(); ++i) {
                    HSSFCell cell = row.createCell(i, CellType.STRING);
                    cell.setCellValue(values.get(i));
                }
            }

            for (int i = 0; i < headers.size(); ++i) {
                sheet.autoSizeColumn(i);
            }
        }

        //设置文件名
        response.setContentType("application/vnd.ms-excel");
        response.setHeader("Content-disposition", "attachment;filename=" + "export_" + DateFormatUtils.format(new Date(), "yyyy-MM-dd") + ".xls");
        try {
            OutputStream outputStream = response.getOutputStream();
            workbook.write(outputStream);
            outputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }