What is the best way to stream files from server to browser using Quarkus with least overhead?

[hellraiserinchief]

It looks like OutputStreams is not supported. I wrote the following code to test the streaming support but it does not work as expected.

    @GET
    @Path("thumbnail")
    @Produces(MediaType.APPLICATION_OCTET_STREAM)
    public Response hello() {
        StreamingOutput stream = new StreamingOutput() {
            @Override
            public void write(OutputStream os) throws IOException, WebApplicationException {
                String filename = "path-to-jpeg";
                char[] buffer = new char[1024*1024];
                Writer writer = new BufferedWriter(new OutputStreamWriter(os));
                Reader in = new BufferedReader(new FileReader(filename));
                int len;
                while((len = in.read(buffer)) > 0) {
                    writer.write(buffer, 0, len);
                    //write(buffer, 0, len);
                }
                writer.flush();
            }
        };
        return Response.ok(stream).header("Content-Type", "IMAGE/JPEG").build();

[hellraiserinchief]

Below works but not sure if it is using streams in the backend.

public Uni<Response> downloadImages(@NotNull String dataURL) {
    File nf = new File(dataURL);
    if (!Files.exists(nf.toPath())) {
      LOG.error("File does not exist");
        return Uni.createFrom().item(Response.status(Status.NOT_FOUND).build());
    }
    ResponseBuilder response = Response.ok((Object) nf);
    response.header("Content-Disposition", "attachment;filename=" + nf.getName());
    Uni<Response> re = Uni.createFrom().item(response.build());
    return re;
  }