<dependency>
     <groupId>org.apache.poi</groupId>
     <artifactId>poi-ooxml</artifactId>
     <version>3.17</version>
 </dependency>

public String exportExcel(String startTime,String endTime,HttpServletResponse response) throws IOException {
        List<store_order> list = emptySpecialStoreService.selectOrderbyTime(startTime, endTime);
    String fileName = "orderInfo"; //设置导出excel文件名称
    HSSFWorkbook workbook = new HSSFWorkbook(); //创建Excel工作薄对象
    HSSFSheet sheet = workbook.createSheet();  //创建工作表对象
    sheet.setColumnWidth(12,5000);   //设置表的最后一列第12列的宽度//设置表头字体样式
    HSSFFont font = workbook.createFont();
    font.setFontName("宋体");
    font.setFontHeightInPoints((short)10); //设置字号
    font.setBold(true);  //设置加粗
    
    //HSSFCellStyle cellStyle = workbook.createCellStyle(); //设置列字体，这里暂不设置
    
    HSSFRow row0 = sheet.createRow(0); //创建第一行，第一行为每一列的标题
    
    String[] cellTitle={"订单号","用户账号","商品名称","优惠前价格","优惠后价格","商品类型","KT币数量","收件人姓名","收件人地址","收件人手机号","商品来源","订单状态","创建时间"};
    for(int i=0;i<cellTitle.length;i++) {
       HSSFCell cell = row0.createCell(i);  //依次设置列标题
       cell.setCellValue(cellTitle[i]);
    }
    //表格中数据总共12列，循环新建一行，然后把对象中的值依次写入到这一行中的每一列
    for(int i=0;i<list.size();i++) {
      HSSFRow row = sheet.createRow(i+1);  //创建新的一行
      store_order order = list.get(i);
      
      HSSFCell cell0 = row.createCell(0); //依次为当前行的每一列添加数据
      cell0.setCellValue(order.getStore_order_id());
      
      HSSFCell cell1 = row.createCell(1); 
      cell1.setCellValue(order.getUsercode());
      
      HSSFCell cell2 = row.createCell(2); 
      cell2.setCellValue(order.getProduct_name());
      
      HSSFCell cell3 = row.createCell(3); 
      cell3.setCellValue(order.getPrice_before());
      
      HSSFCell cell4 = row.createCell(4); 
      cell4.setCellValue(order.getPrice_after());
      
      HSSFCell cell5 = row.createCell(5); 
      cell5.setCellValue(order.getProduct_type());
      
      HSSFCell cell6 = row.createCell(6); 
      cell6.setCellValue(order.getAmountKT());
      
      HSSFCell cell7 = row.createCell(7); 
      cell7.setCellValue(order.getPeople_name());
      
      HSSFCell cell8 = row.createCell(8); 
      cell8.setCellValue(order.getPeople_address());
      
      HSSFCell cell9 = row.createCell(9); 
      cell9.setCellValue(order.getPeople_mobile());
      
      HSSFCell cell10 = row.createCell(10); 
      cell10.setCellValue(order.getProduct_source());
      
      HSSFCell cell11 = row.createCell(11);
      cell11.setCellValue(order.getProduct_status());

      HSSFCell cell12 = row.createCell(12); 
      cell12.setCellValue(order.getCreate_time());
    }
     
    OutputStream os = response.getOutputStream();
    response.reset(); //重置输出流
    //设置输出头文件
    response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes("GB2312"), "8859_1") + ".xls"); //.xls是excel文件的后缀
    //定义输出头类型
    response.setContentType("application/msexcel");
    workbook.write(os);
    os.close();
    
    System.out.println("导出完成=============");
    return "导出成功！";
  }