文件下载,excel导出

exportExcel(){
    //获取弹框,并且弹出保存框
    let iframe = document.getElementById('downloadIframe');
    if (!iframe) {
      iframe = document.createElement('iframe');
      iframe.id = 'downloadIframe';
      iframe.style.display = 'none';
      document.body.appendChild(iframe);
    }
    //拼接路径,并调用相关下载的接口,返回的数据类型是bytes[]数组
    iframe.src = "http://localhost:8001/cft/user/uploadExcel"
}

@GetMapping("/uploadExcel")
public ResponseEntity<byte []> testExportTest() throws IOException {

    String  [] excelheader  = {"项目","电话","联系人","金额","负责人","周期"};

    //创建文档对象
    HSSFWorkbook wb = new HSSFWorkbook();
    // 建立新的sheet对象（excel的表单）
    HSSFSheet sheet = wb.createSheet("项目信息统计");
    HSSFRow rowHead = sheet.createRow(0);

    // 创建第一行
    for (int i = 0; i < excelheader.length; i++) {
        rowHead.createCell(i).setCellValue(excelheader[i]);
    }
    HSSFRow row = sheet.createRow(1);
    row.createCell(0).setCellValue("社工协议");
    row.createCell(1).setCellValue("15071384121");
    row.createCell(2).setCellValue("王凯");
    row.createCell(3).setCellValue("500");
    row.createCell(4).setCellValue("周三");
    row.createCell(5).setCellValue("150");

    ByteArrayOutputStream os = new ByteArrayOutputStream();
    wb.write(os);
    os.flush();

    String fileName ="项目信息导出.xls";
    fileName = new String(fileName.getBytes("utf-8"),"ISO_8859_1");

    HttpHeaders httpHeaders = new HttpHeaders();
    httpHeaders.setContentType(MediaType.APPLICATION_OCTET_STREAM);
    httpHeaders.setContentDispositionFormData("attachment", fileName);

    //这里需要注意的事返回的数据类型是指定的
    return new  ResponseEntity<byte[]>(os.toByteArray(),httpHeaders,HttpStatus.OK);
}