如果我使用单个pubnub实例多次订阅某个频道,会发生什么？

Question

如果我已经使用单个pubnub实例多次订阅了一个频道,它是否会订阅,如果它订阅了哪个回调将被执行？

Answer 1

PubNub订阅connectCallback行为

当您成功订阅频道时,connectCallback将会被呼叫.

每次你打电话subscribe到不同的频道后,connectCallback都会被调用.

但是,如果您订阅了您已订阅的频道,则connectCallback不会被调用(基本上是无操作).

示例Java/Android subscribe代码:

pubnub.subscribe("my_channel", new Callback() {

          @Override
          public void connectCallback(String channel, Object message) {
              System.out.println("SUBSCRIBE : CONNECT on channel:" + channel
                         + " : " + message.getClass() + " : "
                         + message.toString());
          }

          @Override
          public void disconnectCallback(String channel, Object message) {
              System.out.println("SUBSCRIBE : DISCONNECT on channel:" + channel
                         + " : " + message.getClass() + " : "
                         + message.toString());
          }

          public void reconnectCallback(String channel, Object message) {
              System.out.println("SUBSCRIBE : RECONNECT on channel:" + channel
                         + " : " + message.getClass() + " : "
                         + message.toString());
          }

          @Override
          public void successCallback(String channel, Object message) {
              System.out.println("SUBSCRIBE : " + channel + " : "
                         + message.getClass() + " : " + message.toString());
          }

          @Override
          public void errorCallback(String channel, PubnubError error) {
              System.out.println("SUBSCRIBE : ERROR on channel " + channel
                         + " : " + error.toString());
          }
      }
);