通过 HTML5 视频元素进行 Java 多媒体流传输

Question

我试图让我的 Java 后端将视频文件（MP4 等）“流式传输”到浏览器。我担心我必须编写非常复杂的、低级的 NIO 类型代码，例如：

public class VideoController extends HttpServlet {
    @Override
    public void doGet(HttpServletRequest req, HttpServletResponse resp) {
        File f = new File("/opt/videos/video19394.mp4");
        PrintStream ps = resp.getWriter();

        while(still reading f) {
            writeTheVideoBytesToStream(f, ps);
        }
    }
}

但看起来这一切都是由 HTML5 元素解决的<video/>（是吗？？）。这样，从客户端，我可以指定：

<video width="500" height="500" url="http://myapp.example.com/videos/19394" />

然后，在服务器端，即使是像 一样简单的内容，我也可以指定 URL 请求（例如）和位于 的服务器上的 MP4 文件web.xml之间的映射。还有http://myapp.example.com/videos/19394/opt/videos/video19394.mp4<video/>元素只是自动处理事情。

我在这里是否正确，或者即使我使用了<video/>，我仍然需要在服务器上实现低级字节/套接字流内容？

Answer 1

您可以使用 Spring Boot 框架并仅从 REST 端点提供 InputStream。这也将允许使用 HTML5 中的视频标签进行滚动。

代码看起来像这样：

@RequestMapping(value = "videos/file-name", method = GET)
@ResponseBody
public final ResponseEntity<InputStreamResource> 
retrieveResource(@PathVariable(value = "file-name")
final String fileName,
@RequestHeader(value = "Range", required = false)
String range) throws Exception {

long rangeStart = Longs.tryParse(range.replace("bytes=","").split("-")[0]);//parse range header, which is bytes=0-10000 or something like that
long rangeEnd = Longs.tryParse(range.replace("bytes=","").split("-")[0]);//parse range header, which is bytes=0-10000 or something like that
long contentLenght = ;//you must have it somewhere stored or read the full file size

InputStream inputStream = Resources.getResource(fileName).openStream();//or read from wherever your data is into stream
HttpHeaders headers = new HttpHeaders();
headers.setContentType("video/mp4");
headers.set("Accept-Ranges", "bytes");
headers.set("Expires", "0");
headers.set("Cache-Control", "no-cache, no-store");
headers.set("Connection", "keep-alive");
headers.set("Content-Transfer-Encoding", "binary");
headers.set("Content-Length", String.valueOf(rangeEnd - rangeStart));

//if start range assume that all content
if (rangeStart == 0) {
  return new ResponseEntity<>(new InputStreamResource(inputStream), headers, OK);
} else {
  headers.set("Content-Range", format("bytes %s-%s/%s", rangeStart, rangeEnd, contentLenght));
  return new ResponseEntity<>(new InputStreamResource(inputStream), headers, PARTIAL_CONTENT);
}
}