Jersey REST 支持简历/媒体流 [英] Jersey REST support resume/media streaming

问题描述

我需要支持 Jersey REST 上的简历，我正在尝试这样做:

I need to support resume on Jersey REST, I'm trying to do it this way:

@Path("/helloworld")
public class RestServer {

@GET

@Path("say")
@Produces("audio/mp3")
public Response getMessage(@HeaderParam("Range") String r ) throws IOException{
    String str="/Users/dima/Music/crazy_town_-_butterfly.mp3";

    System.out.println(r);
    RandomAccessFile f=new RandomAccessFile(str, "r");

    int off=0;
    int to=(int)f.length();
    byte[] data ;
    if(r!=null){
        String from=r.split("=")[1].split("-")[0];
        String t=r.split("=")[1].split("-")[1];
        off=Integer.parseInt(from);
        to=Integer.parseInt(t);

    }
    data= new byte[to-off];
    f.readFully(data, off, to-off);

    ResponseBuilder res=Response.ok(data)
            .header("Accept-Ranges","bytes")
            .header("Content-Range:", "bytes "+off+"-"+to+"/"+data.length)
            .header("Pragma", "no-cache");;

            if(r==null){
                res=res.header("Content-Length", data.length);
            }
            f.close();

            Response ans=res.build();

            return ans;


}
}

我希望能够流式传输 mp3，以便浏览器可以搜索音乐，但在 safari 中它仍然无法正常工作.有什么想法吗?

I want to be able stream mp3 so the browser can seek the music, but in safari it still not working. any ideas?

推荐答案

这是我基于提供的解决方案的看法 这里.它可以在不同的浏览器上正常工作.我也可以在 Safari 和其他浏览器中很好地寻找音乐.您可以在我的 Github repository 上找到示例项目，其中包含更多详细信息.Chrome 和 Safari 很好地利用了范围标头来流式传输媒体，您可以在请求/响应跟踪中看到它.

Here is my take based on the solution provided here. It works correctly on different browsers. I am able to seek the music just fine in Safari and other browsers as well. You can find the sample project on my Github repository which has more details. Chrome and Safari nicely leverages the range headers to stream media and you can see it in the request/response trace.

    @GET
    @Produces("audio/mp3")
    public Response streamAudio(@HeaderParam("Range") String range) throws Exception {
        return buildStream(audio, range);
    }

    private Response buildStream(final File asset, final String range) throws Exception {
        // range not requested : Firefox, Opera, IE do not send range headers
        if (range == null) {
            StreamingOutput streamer = new StreamingOutput() {
                @Override
                public void write(final OutputStream output) throws IOException, WebApplicationException {

                    final FileChannel inputChannel = new FileInputStream(asset).getChannel();
                    final WritableByteChannel outputChannel = Channels.newChannel(output);
                    try {
                        inputChannel.transferTo(0, inputChannel.size(), outputChannel);
                    } finally {
                        // closing the channels
                        inputChannel.close();
                        outputChannel.close();
                    }
                }
            };
            return Response.ok(streamer).header(HttpHeaders.CONTENT_LENGTH, asset.length()).build();
        }

        String[] ranges = range.split("=")[1].split("-");
        final int from = Integer.parseInt(ranges[0]);
        /**
         * Chunk media if the range upper bound is unspecified. Chrome sends "bytes=0-"
         */
        int to = chunk_size + from;
        if (to >= asset.length()) {
            to = (int) (asset.length() - 1);
        }
        if (ranges.length == 2) {
            to = Integer.parseInt(ranges[1]);
        }

        final String responseRange = String.format("bytes %d-%d/%d", from, to, asset.length());
        final RandomAccessFile raf = new RandomAccessFile(asset, "r");
        raf.seek(from);

        final int len = to - from + 1;
        final MediaStreamer streamer = new MediaStreamer(len, raf);
        Response.ResponseBuilder res = Response.status(Status.PARTIAL_CONTENT).entity(streamer)
                .header("Accept-Ranges", "bytes")
                .header("Content-Range", responseRange)
                .header(HttpHeaders.CONTENT_LENGTH, streamer.getLenth())
                .header(HttpHeaders.LAST_MODIFIED, new Date(asset.lastModified()));
        return res.build();
    }

这是 MediaStreamer 的实现，用于在资源方法中流式传输输出.

Here is the MediaStreamer implementation, which is used to stream the output in your resource method.

public class MediaStreamer implements StreamingOutput {

    private int length;
    private RandomAccessFile raf;
    final byte[] buf = new byte[4096];

    public MediaStreamer(int length, RandomAccessFile raf) {
        this.length = length;
        this.raf = raf;
    }

    @Override
    public void write(OutputStream outputStream) throws IOException, WebApplicationException {
        try {
            while( length != 0) {
                int read = raf.read(buf, 0, buf.length > length ? length : buf.length);
                outputStream.write(buf, 0, read);
                length -= read;
            }
        } finally {
            raf.close();
        }
    }

    public int getLenth() {
        return length;
    }
}

这篇关于Jersey REST 支持简历/媒体流的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！