JAVA 使用POI导出数据格式为Execl

@Override
    public void getContractListExecl(Contract contract, BindingResult result, HttpServletRequest req,
            HttpServletResponse response) throws IOException {
     
        List<Map<String, Object>> sttList = contractService.getContracts(contract);// 得到需要导出的数据
        int i = 0;
        // 第一步，创建一个webbook，对应一个Excel文件
        @SuppressWarnings("resource")
        HSSFWorkbook wb = new HSSFWorkbook();
        // 第二步，在webbook中添加一个sheet,对应Excel文件中的sheet
        HSSFSheet sheet = wb.createSheet("title");
         // 设置表格默认列宽度为15个字节  
        sheet.setDefaultColumnWidth((short) 20);
        // 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short
        HSSFRow row = sheet.createRow(i);
        // 第四步，创建单元格，并设置值表头 设置表头居中
        HSSFCellStyle style = wb.createCellStyle();
        style.setAlignment(HSSFCellStyle.ALIGN_LEFT); // 创建一个居中格式

        HSSFCell cell = row.createCell(0);
        cell.setCellValue("用户姓名");
        cell.setCellStyle(style);
        cell = row.createCell(1);

        cell.setCellValue("电话");
        cell.setCellStyle(style);
        cell = row.createCell(2);

        cell.setCellValue("家庭医生团队名称");
        cell.setCellStyle(style);
        cell = row.createCell(3);

        cell.setCellValue("服务办理人姓名");
        cell.setCellStyle(style);
        cell = row.createCell(4);

        cell.setCellValue("服务办理人电话");
        cell.setCellStyle(style);
        cell = row.createCell(5);

        cell.setCellValue("服务办理人代码");
        cell.setCellStyle(style);
        cell = row.createCell(6);

        cell.setCellValue("完成签约时间");
        cell.setCellStyle(style);
        cell = row.createCell(7);

        cell.setCellValue("服务完成ITV编码");
        cell.setCellStyle(style);
        cell = row.createCell(8);

        cell.setCellValue("服务完成时间");
        cell.setCellStyle(style);
        cell = row.createCell(9);

        

        for (Map<String, Object> row_ : sttList) {
            row = sheet.createRow(++i);
            // 第四步，创建单元格，并设置值
            row.createCell(0)
                    .setCellValue(row_.get("userName") == null ? "###" : row_.get("userName").toString());
            row.createCell(1)
                    .setCellValue(row_.get("userPhone") == null ? "###" : row_.get("userPhone").toString());
            row.createCell(2).setCellValue(row_.get("dgName") == null ? "###" : row_.get("dgName").toString());
            row.createCell(3)
                    .setCellValue(row_.get("proxyName") == null ? "###" : row_.get("proxyName").toString());
            row.createCell(4).setCellValue(row_.get("proxyPhone") == null ? "###" : row_.get("proxyPhone").toString());
            row.createCell(5).setCellValue(row_.get("proxyCode") == null ? "###" : row_.get("proxyCode").toString());
            row.createCell(6).setCellValue(row_.get("updateTime") == null ? "###" : row_.get("updateTime").toString());
            row.createCell(7).setCellValue(row_.get("itvToken") == null ? "###" : row_.get("itvToken").toString());
            row.createCell(8).setCellValue(row_.get("itvUpdateTime") == null ? "###" : row_.get("itvUpdateTime").toString());
            
            
        }
        String fileName = new SimpleDateFormat("yyyy-MM-dd").format(new Date());
        response.setHeader("content-disposition",
                "attachment;filename=" + new String(fileName.getBytes("UTF-8"), "ISO8859-1") + ".xls");
        OutputStream fout = response.getOutputStream();
        wb.write(fout);
        fout.close();
    }

}