Is there any way to get upload progress correctly with HttpUrlConncetion

Question

Android Developers Blog recommend to use HttpURLConnection other than apache's HttpClient (http://android-developers.blogspot.com/2011/09/androids-http-clients.html). I take the advice and get problem in reporting file upload progress.

my code to grab progress is like this：

try {
    out = conncetion.getOutputStream();
    in = new BufferedInputStream(fin);
    byte[] buffer = new byte[MAX_BUFFER_SIZE];
    int r;
    while ((r = in.read(buffer)) != -1) {
        out.write(buffer, 0, r);
        bytes += r;
        if (null != mListener) {
            long now = System.currentTimeMillis();
            if (now - lastTime >= mListener.getProgressInterval()) {
                lastTime = now;
                if (!mListener.onProgress(bytes, mSize)) {
                    break;
                }
            }
        }
    }
    out.flush();
} finally {
    closeSilently(in);
    closeSilently(out);
}

this code excutes very fast for whatever file size, but the file is actually still uploading to the server util i get response from the server. it seems that HttpURLConnection caches all data in internal buffer when i call out.write().

So, how can i get the actual file upload progress? Seems like httpclient can do that, but httpclient is not prefered...any idea?

Answer 1

I found the explanation on developer document http://developer.android.com/reference/java/net/HttpURLConnection.html

To upload data to a web server, configure the connection for output using setDoOutput(true).
For best performance, you should call either setFixedLengthStreamingMode(int) when the body length is known in advance, or setChunkedStreamingMode(int) when it is not. Otherwise HttpURLConnection will be forced to buffer the complete request body in memory before it is transmitted, wasting (and possibly exhausting) heap and increasing latency.

Calling setFixedLengthStreamingMode() first fix my problem. But as mentioned by this post, there is a bug in android that makes HttpURLConnection caches all content even if setFixedLengthStreamingMode() has been called, which is not fixed until post-froyo. So i use HttpClient instead for pre-gingerbread.