JAVA导出EXCEL

File file = new File(Utility.getWebInfPath()+File.separator + "Detail.xlsx");
// 获得EXCEL对象
XSSFWorkbook wb = new XSSFWorkbook(new FileInputStream(file));
//向EXCEL文件写数据
service.detailExport(wb,jsonObj);

// excel部署
this.getResponse().setHeader("Content-disposition", "attachment; filename= Detail.xlsx");
// excel
this.getResponse().setHeader("Pragma", "public");
// excel缓存控制，必须刷新
this.getResponse().setHeader("Cache-Control", "must-revalidate");
// 失效期
this.getResponse().setDateHeader("Expires", 0);
// 单元样式
this.getResponse().setContentType("text/csv; charset=UTF-8");
// 导出
wb.write(this.getResponse().getOutputStream());
this.getResponse().getOutputStream().flush();

for (int i = 0; i < jsonArray.size(); i++) {

  Row row = sheet.getRow(i+1);
  for (int j = 0; j < fields.length; j++) {
  String strs[] = fields[j].split("-");
  Cell c = row.getCell(j);
  String value = (String) jsonArray.getJSONObject(i).get(strs[0]);
  c.setCellValue(value);
}
  }