I notice that OkHttp support h2 over ALPN in Android 5.0+.
From some article,I learned that we can use NPN Negotiation for http/2 request.
Can I send http/2 request with OkHttp over NPN Negotiation?
So that it's possible to support h2 on android 4.1+ with better network performance :-D
We dropped NPN support. ALPN is the future.