Cannot use HTTP/2

[amrishodiq]

Hi,
I tried to use OkHttp 3.0.1 to open https://http2.akamai.com/ which is known to be HTTP/2 enabled.
I found that response.protocol() to always returns "http/1.1" instead of "http/2".
I tried both in my desktop and Android.
Here the code I wrote:

        String url = "https://http2.akamai.com/";

        List<Protocol> protocols = new ArrayList<>();
            protocols.add(Protocol.SPDY_3);
            protocols.add(Protocol.HTTP_2);
            protocols.add(Protocol.HTTP_1_1);

        OkHttpClient client = new OkHttpClient.Builder()
                .protocols(protocols)
                .build();
        Request request = new Request.Builder()
            .url(url)
            .build();

        try {
            Response response = client.newCall(request).execute();
            System.out.println("Protocol: "+response.protocol().toString());
        } catch (IOException ex) {
            Logger.getLogger("Test").log(Level.SEVERE, null, ex);
        }

Is it normal?

[dotgc]

Are you running Android 5.0+? http2 support is enabled via ALPN on android 5.0+ only.
See:
https://github.com/square/okhttp/blob/master/okhttp/src/main/java/okhttp3/internal/io/RealConnection.java#L212

https://github.com/square/okhttp/blob/master/okhttp/src/main/java/okhttp3/internal/Platform.java#L154

https://github.com/square/okhttp/blob/master/okhttp/src/main/java/okhttp3/internal/Platform.java#L267

[swankjesse]

Try adding ALPN:
https://github.com/square/okhttp/wiki/Building#desktop-testing-without-maven

[Aman-Aalam]

FYI, as of v3.9.0+, OkHttp is using ALPN provided by Google Play Services, so HTTP2 is supported out of the box