批量选择文件，通过后台打包形成流文件提供给前端下载，一般我们request.js都会做一些验证与报错提示，但是不支持文件下载。

而文件下载中，前端的解决方法可以通过响应头的Content-Type来判断。

直接上代码：

export async function apiBatchSave (params) {
  return fetch(`${API_DOC_JAVA}/batchSave`,{
    method: 'POST',
    headers: {
      'Accept': 'application/json, */*',
      'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8',
      'cache': 'default',
      'x-ajax': 'true'
    },
    'credentials': 'include', //表示请求是否携带cookie
    body: formartBody(params)
  }).then(function (response) {
    if (response.ok) {
      response.blob().then((blob) => {
        const a = window.document.createElement('a');
        const downUrl = window.URL.createObjectURL(blob);// 获取 blob 本地文件连接 (blob 为纯二进制对象，不能够直接保存到磁盘上)
        const filename = response.headers.get('Content-Disposition').split('filename=')[1].split('.');
        a.href = downUrl;
        a.download = `${decodeURI(filename[0])}.${filename[1]}`;
        a.click();
        window.URL.revokeObjectURL(downUrl);
      });
      return {state: 1}
    } else {
      throw new Error('')
    }
  })
}


java后端配置

 

 public void downloadBatchByFile(HttpServletResponse response, Map<String, byte[]> files, String zipName){
        try{
            response.setContentType("application/x-msdownload");
            response.setHeader("content-disposition", "attachment;filename="+ URLEncoder.encode(zipName, "utf-8"));

            ZipOutputStream zos = new ZipOutputStream(response.getOutputStream());
            BufferedOutputStream bos = new BufferedOutputStream(zos);

            for(Map.Entry<String, byte[]> entry : files.entrySet()){
                String fileName = entry.getKey();            //每个zip文件名
                byte[]    file = entry.getValue();            //这个zip文件的字节

                BufferedInputStream bis = new BufferedInputStream(new ByteArrayInputStream(file));
                zos.putNextEntry(new ZipEntry(fileName));

                int len = 0;
                byte[] buf = new byte[10 * 1024];
                while( (len=bis.read(buf, 0, buf.length)) != -1){
                    bos.write(buf, 0, len);
                }
                bis.close();
                bos.flush();
            }
            bos.close();
        }catch(Exception e){
            e.printStackTrace();
        }
    }