nanohttpd 服务视频，如何使其支持视频向前和向后（使服务器支持 http 字节范围）答案

【问题标题】：nanohttpd serve video, how to make it support video forward and backward(make server support http byte range)nanohttpd 服务视频，如何使其支持视频向前和向后（使服务器支持 http 字节范围）
【发布时间】：2020-06-24 08:56:04
【问题描述】：

这是我的代码：

public class VideoServer extends NanoHTTPD {
    public VideoServer() {
        super(8080);
    }

    @Override
    public Response serve(IHTTPSession session) {
        return responseVideoStream(session, "/home/roroco/Dropbox/video/t.mp4");
    }

    public Response responseVideoStream(IHTTPSession session, String videopath) {
        try {
            FileInputStream fis = new FileInputStream(videopath);
            return newChunkedResponse(Response.Status.OK, "video/mp4", fis);
        } catch (FileNotFoundException e) {
            throw new RuntimeException(e);
        }
    }
}

视频投放成功，但不能前进和后退

看我下面的 gif，当我点击时间进度时，视频不能倒退

【问题讨论】：

标签： java android

【解决方案1】：

我从https://stackoverflow.com/a/23620420/6011193 找到解决方案，请参阅它的#getPartialResponse

这是我的最终代码：

public class VideoServer extends NanoHTTPD {
    String filePath = "/home/roroco/Dropbox/video/t.mp4";

    public VideoServer() {
        super(8080);

    }

    @Override
    public Response serve(IHTTPSession session) {
        String range = null;
        Map<String, String> headers = session.getHeaders();
        for (String key : headers.keySet()) {
            if ("range".equals(key)) {
                range = headers.get(key);
                break;
            }
        }
        if (range != null) {
            try {
                return getPartialResponse("video/mp4", range);
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } else {
            return responseVideoStream(session, filePath);
        }
    }

    public Response responseVideoStream(IHTTPSession session, String videopath) {
        try {
            FileInputStream fis = new FileInputStream(videopath);
            return newChunkedResponse(Response.Status.OK, "video/mp4", fis);
        } catch (FileNotFoundException e) {
            throw new RuntimeException(e);
        }
    }

    private Response getPartialResponse(String mimeType, String rangeHeader) throws IOException {
        File file = new File(filePath);
        String rangeValue = rangeHeader.trim().substring("bytes=".length());
        long fileLength = file.length();
        long start, end;
        if (rangeValue.startsWith("-")) {
            end = fileLength - 1;
            start = fileLength - 1
                    - Long.parseLong(rangeValue.substring("-".length()));
        } else {
            String[] range = rangeValue.split("-");
            start = Long.parseLong(range[0]);
            end = range.length > 1 ? Long.parseLong(range[1])
                    : fileLength - 1;
        }
        if (end > fileLength - 1) {
            end = fileLength - 1;
        }
        if (start <= end) {
            long contentLength = end - start + 1;
            FileInputStream fileInputStream = new FileInputStream(file);
            //noinspection ResultOfMethodCallIgnored
            fileInputStream.skip(start);
            Response response = newFixedLengthResponse(Response.Status.PARTIAL_CONTENT, mimeType, fileInputStream, contentLength);
            response.addHeader("Content-Length", contentLength + "");
            response.addHeader("Content-Range", "bytes " + start + "-" + end + "/" + fileLength);
            response.addHeader("Content-Type", mimeType);
            return response;
        } else {
            return newChunkedResponse(Response.Status.INTERNAL_ERROR, "text/html", null);
        }
    }
}

【讨论】：