java - Android Paho 客户端 - 如何启用离线缓冲并在网络启用后发送消息？

Question

我使用 Android Paho 客户端库 v1.1.0，QoS 2。 我通过 MQTT 发布/订阅的代码:

mClient = new MqttAndroidClient(this, uri, clientId, new   MqttDefaultFilePersistence());
MqttConnectOptions conOpt = new MqttConnectOptions();

conOpt.setMqttVersion(MqttConnectOptions.MQTT_VERSION_3_1);
conOpt.setCleanSession(true);
conOpt.setAutomaticReconnect(true);

mClient.setTraceEnabled(true);

mClient.setCallback(this);
mClient.setTraceCallback(this);

IMqttToken connectToken = mClient.connect(conOpt, null, this);

和离线缓冲选项:

@Override
public void onSuccess(IMqttToken iMqttToken) {
    this.disconnectedBufferOptions = new DisconnectedBufferOptions();
    this.disconnectedBufferOptions.setBufferEnabled(true);

    mClient.setBufferOpts(disconnectedBufferOptions);

    subscribe(topic);
}

如果网络可用，则消息发布到主题，但如果禁用并再次启用离线消息，则不会发送。 如何正确启用离线缓冲选项并发送离线消息？ 附加信息:网络禁用并发布消息后 mClient.getBufferedMessageCount() = 0

Answer 1

使用 conOpt.setAutomaticReconnect(true) 以及连接 token onSuccess 中的以下代码 fragment 为我解决了这个问题。

DisconnectedBufferOptions disconnectedBufferOptions = new DisconnectedBufferOptions();

disconnectedBufferOptions.setBufferEnabled(true);
disconnectedBufferOptions.setBufferSize(100);
disconnectedBufferOptions.setPersistBuffer(false);
disconnectedBufferOptions.setDeleteOldestMessages(false);

mClient.setBufferOpts(disconnectedBufferOptions);