Question

我正在尝试从Kaltura下载文件（.mp4），文件超过100mb，以下代码需要花费大量时间才能下载。

还有其他方法可以改善吗？

try {
        URL url = new URL("https://www.kaltura.com/p/....");
        InputStream in = new BufferedInputStream(url.openStream());
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        byte[] buf = new byte[8192];
        int n = 0;
        while (-1 != (n = in.read(buf)))
        {
            out.write(buf);
        }
        out.close();
        in.close();     
        res.setContentType("application/octet-stream");
        res.setHeader("Cache-Control", "no-cache");
        res.setHeader("Content-Disposition","attachment;filename=Smac_03_48.mp4 (iPad).mp4");
        res.setStatus(200);
        res.getOutputStream().write(out.toByteArray());
    } catch (Exception e) {
        e.printStackTrace();
    }

Answer 1

问题是ByteArrayOutputStream会大量增长，不时重新分配它的大小。而是立即输出：

TypeCheckingExtension

当然浏览器重定向会更快。

Answer 2

我尝试使用下面的代码，它按预期工作正常！

URL url = null;
try {
    url = new URL(kalturaUrl);
    HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
    if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
        InputStream inputStream = httpConn.getInputStream();
        response.setContentType(httpConn.getContentType());
        response.setContentLength(httpConn.getContentLength());
        response.setHeader("Content-Disposition", httpConn.getHeaderField("Content-Disposition"));
        OutputStream outputStream = response.getOutputStream();

        int bytesRead = -1;
        byte[] buffer = new byte[8192];
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, bytesRead);
        }

        outputStream.close();
        inputStream.close();
    } else {
        return "No file to download. Server replied HTTP code: " + httpConn.getResponseCode();
    }
    httpConn.disconnect();
} catch (MalformedURLException e) {
    logger.error("Exception : ",e);
} catch (IOException e) {
    logger.error("Exception : ",e);
}

从服务器下载大文件需要很长时间

2 个答案: