///

Avec cela, vous pouvez connecter le WebSocket puis envoyer et recevoir des messages :

<img src="/img/tutorial/websockets/image05.png">

## Gérer les déconnexions et plusieurs clients { #handling-disconnections-and-multiple-clients }

Lorsqu'une connexion WebSocket est fermée, l'instruction `await websocket.receive_text()` lèvera une exception `WebSocketDisconnect`, que vous pouvez ensuite intercepter et gérer comme dans cet exemple.

    /**
     * Negotiate password hashes with MSIE clients using NTLM SSP
     * @param req The servlet request
     * @param resp The servlet response
     * @param skipAuthentication If true the negotiation is only done if it is
     * initiated by the client (MSIE post requests after successful NTLM SSP
     * authentication). If false and the user has not been authenticated yet
     * the client will be forced to send an authentication (server sends

 * called certificate authorities (CAs).
 *
 * Browsers and other HTTP clients need a set of trusted root certificates to authenticate their
 * peers. Sets of root certificates are managed by either the HTTP client (like Firefox), or the
 * host platform (like Android). In July 2018 Android had 134 trusted root certificates for its HTTP
 * clients to trust.
 *

//    //  org.bouncycastle.tls.TlsFatalAlertReceived: handshake_failure(40)
//    platform.assumeNotBouncyCastle()

    val client = makeClient()
    makeRequest(client)

    // As of OkHttp 5 we now apply the ordering from the OkHttpClient, which defaults to MODERN_TLS
    // Clients might need a changed order, but can at least define a preferred order to override that default.
    val socketOrderedByDefaults =

## Do not Separate Schemas { #do-not-separate-schemas }

Now, there are some cases where you might want to have the **same schema for input and output**.

	// If a mux id is specified that mux is pinged.
	// Clients send ping requests.
	OpPing

	// OpPong is a OpPing response returned by the server.
	OpPong

	// OpConnectMux will connect a new mux with optional payload.
	OpConnectMux

	// OpMuxConnectError is an  error while connecting a mux.
	OpMuxConnectError

	// OpDisconnectClientMux instructs a client to disconnect a mux
	OpDisconnectClientMux

     * @return the number of documents processed
     */
    public static long scroll(final String index, final Function<SearchHit, Boolean> callback) {
        final SearchEngineClient client = ComponentUtil.getSearchEngineClient();
        return client.<SearchHit> scrollSearch(index, searchRequestBuilder -> true, (searchResponse, hit) -> hit,
                hit -> callback.apply(hit));
    }

    /**

Nous créons maintenant un modèle `HeroCreate`, c'est celui qui **validera** les données provenant des clients.

Il a les mêmes champs que `HeroBase`, et il a aussi `secret_name`.

Maintenant, lorsque les clients **créent un nouveau héros**, ils enverront `secret_name`, il sera stocké dans la base, mais ces noms secrets ne seront pas renvoyés dans l'API aux clients.

/// tip | Astuce

  fun okHttpClient() {
    val client = OkHttpClient()
    val dispatcher: Dispatcher = client.dispatcher()
    val proxy: Proxy? = client.proxy()
    val protocols: List<Protocol> = client.protocols()
    val connectionSpecs: List<ConnectionSpec> = client.connectionSpecs()
    val interceptors: List<Interceptor> = client.interceptors()
    val networkInterceptors: List<Interceptor> = client.networkInterceptors()

Es gibt viele Situationen, in denen Sie einem Client, der Ihre API nutzt, einen Fehler mitteilen müssen.

Dieser Client könnte ein Browser mit einem Frontend sein, ein Code von jemand anderem, ein IoT-Gerät usw.

Sie könnten dem Client mitteilen müssen, dass:

* Der Client nicht genügend Berechtigungen für diese Operation hat.
* Der Client keinen Zugriff auf diese Ressource hat.
* Die Ressource, auf die der Client versucht hat, zuzugreifen, nicht existiert.