Android segmented downloading

Question

I'm still new to Android, so, I'm still not so familiar with its libraries and APIs.

My first major project is a download manager which supports segmented downloading. I could already download files, but, I still have no idea on how or where to start for segmented downloading.

I have already browsed a lot of threads, but I really couldn't find any article or thread about segmented downloading in Android.

Can anyone please help me?

Search for some open source android torrent clients. – Sep 09 '12 at 08:54 — , Sep 09 '12 at 08:54

score 2 · Answer 1 · edited May 23 '17 at 10:09

This thread should help you : link

The idea is to use the Content-Range keyword in the header of your request (the server you are contacting has to be able to manage it)

sample code you can draw inspiration from :

public String readFirstChunk(String urlString, int byteCount) {
    String text = null;
    if (urlString != null) {
        org.restlet.Client restletClient = new org.restlet.Client(Protocol.HTTP);
        Request request = new Request(Method.GET, urlString);
        List<Range> ranges = Collections.singletonList(new Range(0, byteCount));
        request.setRanges(ranges);
        Response response = restletClient.handle(request);
        if (Status.SUCCESS_OK.equals(response.getStatus())) {
            text = processSuccessfulChunkRequest(response);
        } else if (Status.SUCCESS_PARTIAL_CONTENT .equals(response.getStatus())) {
            text = processSuccessfulChunkRequest(response);
        } else {
            System.err.println("FAILED "+response.getStatus());
        }
    }
    return text;
}

private String processSuccessfulChunkRequest(Response response) {
    String text = null;
    try {
        text = response.getEntity().getText();
    } catch (IOException e) {
        throw new RuntimeException("Cannot download chunk", e);
    }
    return text;
}

Does this implementation of segmented download use the android's download manager class? — xRev, Sep 21 '12 at 06:16

score 0 · Answer 2 · answered Sep 09 '12 at 08:55

You should study the Accept-Ranges header and also, the HttpClient class in Android.

Segmented downloading will just involve sending different values in the Accept-Ranges header via a request using HttpClient, receive partial content, and then merging all of the received content into one file.

Android segmented downloading

2 Answers2