根据模板EXCEL文件导出

@GetMapping("/export")
public void exportExcel(HttpServletResponse response) throws Exception {

    String filePathName ="E:/gitpro/*****/upload/temp";
    String fileName ="/cccc.xls";
    String exportExcelName="bbbbb.xls";

    List<CompanyExcelBO> list = companyService.exortExcel();

        ByteArrayOutputStream os = new ByteArrayOutputStream();
        exportExcel(list, os,filePathName,fileName);
    try {
        byte[] content = os.toByteArray();
        InputStream is = new ByteArrayInputStream(content);
        // 设置response参数，可以打开下载页面
        response.reset();
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=utf-8");
        response.setHeader("Content-Disposition", "attachment;filename=" + new String(exportExcelName.getBytes("gb2312"), "ISO8859-1"));
        response.setContentLength(content.length);
        ServletOutputStream outputStream = response.getOutputStream();
        BufferedInputStream bis = new BufferedInputStream(is);
        BufferedOutputStream bos = new BufferedOutputStream(outputStream);
        byte[] buff = new byte[8192];
        int bytesRead;
        while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
            bos.write(buff, 0, bytesRead);
        }
        bis.close();
        bos.close();
        outputStream.flush();
        outputStream.close();
    } catch (Exception e) {
        e.printStackTrace();
    }

}

private String exportExcel(List<CompanyExcelBO> list, OutputStream out,String filePathName,String fileName ) {

    int widthCellNumber=10;
    
    try{
        // 读进一个excel模版
        FileInputStream fos = new FileInputStream(filePathName +fileName );
        POIFSFileSystem fs = new POIFSFileSystem(fos);
        // 第一步，创建一个webbook，对应一个Excel文件
        Boolean is03Excel = ExcelVaildateUtils.isExcel(filePathName+fileName);
        //1.创建工作簿
        HSSFWorkbook workbook = new HSSFWorkbook(fs);
        //1.1创建合并单元格对象
        CellRangeAddress callRangeAddress = new CellRangeAddress(0,0,0,widthCellNumber-1);//起始行,结束行,起始列,结束列
        //1.2头标题样式
        //2.创建工作表
        HSSFSheet sheet = workbook.getSheetAt(0);

    //4.操作单元格;将用户列表写入excel
    if (list != null) {
        for (int j = 0; j < list.size(); j++) {
            //创建数据行,前面有两行,头标题行和列标题行
            HSSFRow row3 = sheet.createRow(j + 3);
            row3.createCell(0).setCellValue(list.get(j).getxxx());
            row3.createCell(1).setCellValue(list.get(j).getxxx());
            row3.createCell(2).setCellValue(list.get(j).getxxx());

        }
    }

        workbook.write(out);
        workbook.close();
    } catch (Exception e) {
        logger.info("exportExcel==>{}",e.getMessage());
        e.printStackTrace();
    }

    return EXPORT_STATE_OK;
}