Today Jake Wharton posted an announcement on his medium blog that OkHttp version 3.5 released today includes support for Web Sockets.
Web Sockets provide full-duplex communication channels over a single tcp connection and is being standardized by the W3C. The can be used to implement client server web based applications.
With the update to the library you create a new web socket by passing a request tot he newWebSocket() method along with a listener for messages sent by the server.
Web Sockets now shipping in OkHttp 3.5! – Square Corner Blog – Medium
OkHttpClient client = new OkHttpClient();
Request request = //... WebSocketListener listener = //...
WebSocket ws = client.newWebSocket(request, listener);
To use version 3.5 in your application add the library to your build.gradle file using the follinw line or via the Android Studio Dependencies tab in the Project Structure Dialog.