Okhttp authenticator

auth.java

 final OkHttpClient client = new OkHttpClient.Builder()
       . authenticator(new Authenticator() {
            @Override public Request authenticate(Route route, Response response) throws IOException {
                if (response.request().header("Authorization") != null) {
                    return null; // Give up, we've already attempted to authenticate.
                }
                String credential = Credentials.basic("jesse", "password1");
                return response.request().newBuilder()
                        .header("Authorization", credential)
                        .build();
            }
        })