Iniciar a conexão do WebSocket para o Azure Web PubSub
Artigo
Os clientes conectam-se ao serviço Azure Web PubSub usando o protocolo padrão WebSocket. Você pode usar idiomas que têm suporte ao cliente WebSocket para gravar um cliente para o serviço. Neste artigo, você verá várias amostras de cliente WebSocket em diferentes linguagens.
Autorização
Web PubSub usa um JSON Web Token (JWT) para validar e autorizar clientes. Os clientes podem colocar o token no access_tokenparâmetro de consulta ou colocá-lo no cabeçalhoAuthorization ao se conectarem ao serviço.
Em um fluxo de trabalho típico, o cliente se comunica com o servidor de aplicativos primeiro para obter a URL do serviço e o token. Em seguida, o cliente abre a conexão WebSocket com o serviço usando a URL e o token recebidos.
O portal também fornece uma ferramenta para gerar a URL do cliente com o token dinamicamente. Essa ferramenta pode ser útil para fazer um teste rápido.
Observação
Certifique-se de incluir apenas as funções necessárias ao gerar o token.
Para simplificar o fluxo de trabalho de exemplo, nas seções abaixo, usamos essa URL gerada temporariamente do portal para que o cliente se conecte. Usamos <Client_URL_From_Portal> para representar o valor. Por padrão, o token gerado expira em 60 minutos. Portanto, não se esqueça de gerar um novo quando este expirar.
O serviço oferece suporte a dois tipos de clientes WebSocket: um é o cliente WebSocket simples, e o outro é o cliente WebSocket do PubSub. Aqui mostramos como esses dois tipos de clientes se conectam ao serviço. Para obter mais informações sobre esses clientes, consulte protocolos de cliente WebSocket para Azure Web PubSub.
<script>
// Don't forget to replace this <Client_URL_From_Portal> with the value fetched from the portal
let ws = new WebSocket("<Client_URL_From_Portal>");
ws.onopen = () => {
// Do things when the WebSocket connection is established
};
ws.onmessage = event => {
// Do things when messages are received.
};
</script>
const WebSocket = require('ws');
// Don't forget to replace this <Client_URL_From_Portal> with the value fetched from the portal
const client = new WebSocket("<Client_URL_From_Portal>");
client.on('open', () => {
// Do things when the WebSocket connection is established
});
client.on('message', msg => {
// Do things when messages are received.
});
import asyncio
import websockets
async def hello():
# Don't forget to replace this <Client_URL_From_Portal> with the value fetched from the portal
uri = '<Client_URL_From_Portal>'
async with websockets.connect(uri) as ws:
while True:
await ws.send('hello')
greeting = await ws.recv()
print(greeting)
asyncio.get_event_loop().run_until_complete(hello())
using System;
using System.IO;
using System.Text;
using System.Threading.Tasks;
using Websocket.Client;
namespace subscriber
{
class Program
{
static async Task Main(string[] args)
{
// Don't forget to replace this <Client_URL_From_Portal> with the value fetched from the portal
using (var client = new WebsocketClient(new Uri("<Client_URL_From_Portal>")))
{
// Disable the auto disconnect and reconnect because the sample would like the client to stay online even if no data comes in
client.ReconnectTimeout = null;
client.MessageReceived.Subscribe(msg => Console.WriteLine($"Message received: {msg}"));
await client.Start();
Console.WriteLine("Connected.");
Console.Read();
}
}
}
}
package client;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.WebSocket;
import java.util.concurrent.CompletionStage;
/**
* A simple WebSocket Client.
*
*/
public final class SimpleClient {
private SimpleClient() {
}
/**
* Starts a simple WebSocket connection.
* @param args The arguments of the program.
*/
public static void main(String[] args) throws Exception {
// Don't forget to replace this <Client_URL_From_Portal> with the value fetched from the portal
WebSocket ws = HttpClient.newHttpClient().newWebSocketBuilder()
.buildAsync(URI.create("<Client_URL_From_Portal>"), new WebSocketClient()).join();
System.in.read();
}
private static final class WebSocketClient implements WebSocket.Listener {
private WebSocketClient() {
}
@Override
public void onOpen(WebSocket webSocket) {
System.out.println("onOpen using subprotocol " + webSocket.getSubprotocol());
WebSocket.Listener.super.onOpen(webSocket);
}
@Override
public CompletionStage<?> onText(WebSocket webSocket, CharSequence data, boolean last) {
System.out.println("onText received " + data);
return WebSocket.Listener.super.onText(webSocket, data, last);
}
@Override
public void onError(WebSocket webSocket, Throwable error) {
System.out.println("Bad day! " + webSocket.toString());
WebSocket.Listener.super.onError(webSocket, error);
}
}
}
<script>
// Don't forget to replace this <Client_URL_From_Portal> with the value fetched from the portal
let ws = new WebSocket("<Client_URL_From_Portal>", 'json.webpubsub.azure.v1');
ws.onopen = () => {
// Do things when the WebSocket connection is established
};
ws.onmessage = event => {
// Do things when messages are received.
};
</script>
const WebSocket = require('ws');
// Don't forget to replace this <Client_URL_From_Portal> with the value fetched from the portal
const client = new WebSocket("<Client_URL_From_Portal>", "json.webpubsub.azure.v1");
client.on('open', () => {
// Do things when the WebSocket connection is established
});
client.on('message', msg => {
// Do things when messages are received.
});
import asyncio
import websockets
async def join_group():
# Don't forget to replace this <Client_URL_From_Portal> with the value fetched from the portal
uri = '<Client_URL_From_Portal>'
async with websockets.connect(uri, subprotocols=['json.webpubsub.azure.v1']) as ws:
await ws.send('{"type":"joinGroup","ackId":1,"group":"group1"}')
return await ws.recv()
print(asyncio.get_event_loop().run_until_complete(join_group()))
using System;
using System.IO;
using System.Net.WebSockets;
using System.Text;
using System.Threading.Tasks;
namespace subscriber
{
class Program
{
static async Task Main(string[] args)
{
// Don't forget to replace this <Client_URL_From_Portal> with the value fetched from the portal
using (var client = new WebsocketClient(new Uri("<Client_URL_From_Portal>"), () =>
{
var inner = new ClientWebSocket();
inner.Options.AddSubProtocol("json.webpubsub.azure.v1");
return inner;
}))
{
// Disable the auto disconnect and reconnect because the sample would like the client to stay online even if no data comes in
client.ReconnectTimeout = null;
client.MessageReceived.Subscribe(msg => Console.WriteLine($"Message received: {msg}"));
await client.Start();
Console.WriteLine("Connected.");
Console.Read();
}
}
}
}
package client;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.WebSocket;
import java.util.concurrent.CompletionStage;
/**
* A PubSub WebSocket Client.
*
*/
public final class SubprotocolClient {
private SubprotocolClient() {
}
/**
* Starts a PubSub WebSocket connection.
* @param args The arguments of the program.
*/
public static void main(String[] args) throws Exception {
// Don't forget to replace this <Client_URL_From_Portal> with the value fetched from the portal
WebSocket ws = HttpClient.newHttpClient().newWebSocketBuilder().subprotocols("json.webpubsub.azure.v1")
.buildAsync(URI.create("<Client_URL_From_Portal>"), new WebSocketClient()).join();
ws.sendText("{\"type\":\"joinGroup\",\"ackId\":1,\"group\":\"group1\"}", true);
System.in.read();
}
private static final class WebSocketClient implements WebSocket.Listener {
private WebSocketClient() {
}
@Override
public void onOpen(WebSocket webSocket) {
System.out.println("onOpen using subprotocol " + webSocket.getSubprotocol());
WebSocket.Listener.super.onOpen(webSocket);
}
@Override
public CompletionStage<?> onText(WebSocket webSocket, CharSequence data, boolean last) {
System.out.println("onText received " + data);
return WebSocket.Listener.super.onText(webSocket, data, last);
}
@Override
public void onError(WebSocket webSocket, Throwable error) {
System.out.println("Bad day! " + webSocket.toString());
WebSocket.Listener.super.onError(webSocket, error);
}
}
}
Próximas etapas
Neste artigo, mostramos como se conectar ao serviço usando a URL gerada no portal. Confira os tutoriais abaixo para ver como os clientes se comunicam com o servidor de aplicativos para obter a URL em aplicativos do mundo real.
