OkHttpClient

public class Server {

    private Server() {
    }

    private static Gson sGson;

    /**
     * Check if the application is connected to internet
     *
     * @return true if connected (mobile or wifi), false otherwise
     */
    public static boolean hasConnectivity(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();

        return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
    }

    public static boolean hasWifiConnectivity(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();

        return activeNetwork != null && activeNetwork.getType() == ConnectivityManager.TYPE_WIFI;
    }

    public static OkHttpClient getHttpClient(boolean secured) {
        HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
        logging.setLevel(HttpLoggingInterceptor.Level.BODY);

        OkHttpClient.Builder okHttpClientBuilder = new OkHttpClient.Builder()
                .connectTimeout(30, TimeUnit.SECONDS)
                .readTimeout(30, TimeUnit.SECONDS));

        if (BuildConfig.DEBUG) {
            okHttpClientBuilder.addInterceptor(logging);
        }

        return okHttpClientBuilder.build();
    }

    public static APIError parseError(Throwable e) {
        if (e instanceof HttpException) {
            HttpException httpException = (HttpException) e;
            return sGson.fromJson(httpException.response().errorBody().charStream(), APIError.class);
        }
        return null;
    }
}

/* Translation de "Index" vers "". */
    @OnClick(R.id.indexActivity_boutonConnexion)
    public void indexActivity_boutonConnexion_clique()
    {

------- OkHttpClient ici ? -------

        /* Création du lien "lien_Index_" entre les classes "Index" et "". */
        Intent lien_Index_ = new Intent(Index.this, .class);
        /* Lancement de la translation. */
        startActivity(lien_Index_);
    }

------- OkHttpClient ici ? -------

/* Translation de "Index" vers "". */
    @OnClick(R.id.indexActivity_boutonConnexion)
    public void indexActivity_boutonConnexion_clique()
    {
        /* Création du lien "lien_Index_" entre les classes "Index" et "". */
        Intent lien_Index_ = new Intent(Index.this, .class);
        /* Lancement de la translation. */
        startActivity(lien_Index_);
    }

@OnClick(R.id.indexActivity_boutonConnexion)
    public void indexActivity_boutonConnexion_clique()
    {
        OkHttp okClient = Server.getHttpClient(false);
        // ...
    }

J'ai vu également qu'il était possible de créer un fichier de cache. Nécessaire ou pas ?

////////////\\\\\\\\\\\\
    //!\\ INTERACTIONS //!\\
    ////////////\\\\\\\\\\\\

    /* Implémentation des différentes ressources prédéclarées. */
    final EditText pseudo = (EditText) indexActivity_blocPseudo_champs;
    final EditText motDePasse = (EditText) indexActivity_blocMotDePasse_champs;
    final EditText pseudoVerification = (EditText) indexActivity_blocVerificationPseudo_champs;
    final EditText motDePasseVerification = (EditText) indexActivity_blocVerificationMotDePasse_champs;
    final EditText eMail = (EditText) indexActivity_blocEmail_champs;
    final EditText eMailVerification = (EditText) indexActivity_blocVerificationEmail_champs;

    /* Translation de "Index" vers "". */
    @OnClick(R.id.indexActivity_boutonInscription)
    public void indexActivity_boutonInscription_clique()
    {
        //...

---------- APPEL DU CLIENT ICI ? ----------

        //!\\ Instructions de la translation. //!\\
        /* Création du lien "lien_Index_" entre les classes "Index" et "". */
        Intent lien_Index_ = new Intent(Index.this, .class);
        /* Lancement de la translation. */
        startActivity(lien_Index_);
    }
}