How to track the progress of any OkHttp request body. Licence: MIT

1. Usage.md

How to track the progress of any OkHttp request body

Requires OkHttp >= 2.1.0 if you need to work with multipart request bodies. Lower versions don’t report the content length for the body, but the sum of the sizes of the parts is a pretty good approximation.

// TODO: Build a request body
RequestBody body = null;

// Decorate the request body to keep track of the upload progress
CountingRequestBody countingBody = new CountingRequestBody(body,
        new CountingRequestBody.Listener() {

    @Override
    public void onRequestProgress(long bytesWritten, long contentLength) {
        float percentage = 100f * bytesWritten / contentLength;
        // TODO: Do something useful with the values
    }
});

// TODO: Build a request using the decorated body

CountingRequestBody.java

import com.squareup.okhttp.MediaType;
import com.squareup.okhttp.RequestBody;

import java.io.IOException;

import okio.Buffer;
import okio.BufferedSink;
import okio.ForwardingSink;
import okio.Okio;
import okio.Sink;

/**
 * Decorates an OkHttp request body to count the number of bytes written when writing it. Can
 * decorate any request body, but is most useful for tracking the upload progress of large
 * multipart requests.
 *
 * @author Leo Nikkilä
 */
public class CountingRequestBody extends RequestBody {

    protected RequestBody delegate;
    protected Listener listener;

    protected CountingSink countingSink;

    public CountingRequestBody(RequestBody delegate, Listener listener) {
        this.delegate = delegate;
        this.listener = listener;
    }

    @Override
    public MediaType contentType() {
        return delegate.contentType();
    }

    @Override
    public long contentLength() {
        return delegate.contentLength();
    }

    @Override
    public void writeTo(BufferedSink sink) throws IOException {
        BufferedSink bufferedSink;

        countingSink = new CountingSink(sink);
        bufferedSink = Okio.buffer(countingSink);

        delegate.writeTo(bufferedSink);

        bufferedSink.flush();
    }

    protected final class CountingSink extends ForwardingSink {

        private long bytesWritten = 0;

        public CountingSink(Sink delegate) {
            super(delegate);
        }

        @Override
        public void write(Buffer source, long byteCount) throws IOException {
            super.write(source, byteCount);

            bytesWritten += byteCount;
            listener.onRequestProgress(bytesWritten, contentLength());
        }

    }

    public static interface Listener {

        public void onRequestProgress(long bytesWritten, long contentLength);

    }

}