java - MqttClient 对象的同步和异步接口(interface)不起作用

标签 java mqtt messagebroker mosquitto paho

我创建了一个类型为 MqttClient客户端,如下面的代码所示,我创建了一个客户端并设置了它的异步回调。问题是,

1-当我运行程序时,System.out.println("Client is Connected"); 出现,但我没有收到来自 onSuccess 的响应或来自 oonFailure,为什么?我在代码中做错了什么。

2-i 实现了 static IMqttAsyncClient asynchClientCB = new IMqttAsyncClient() 接口(interface),但是因为我有一个 MqttClient 类型的客户端,所以我不能使用这个 IMqttAsyncClient 接口(interface)。我尝试使用 mqttAsynchClien 但因为我为 java 而不是为 Android 编程,所以我无法使用它。如何使用IMqttAsyncClient接口(interface)?

Update_1

在下面的代码“Updated_code_1”中,我稍微修改了代码,但我希望每次成功连接到 broker 时,onSuccess 同步回调中​​的消息是打印,并在连接终止的情况下打印 onFailure 同步回调中​​的消息,例如当我故意断开网络时。但是在我连接到 broker 时,onSuccessonFailur 都没有显示任何内容。那么,它们的设计用途是什么?

*Update_2_17_Dec_2014

我有一个问题可能会引导我们找到解决方案,也就是说,我是否通过有线/无线网络连接到代理有关系吗?这会改变同步和异步监听器的行为吗?

Updated_1_code:

MqttConnectOptions opts = getClientOptions();
        client = MQTTClientFactory.newClient(broker, port, clientID);

        if (client != null) {
            System.out.println("Client is not Null");
            client.setCallback(AsynchCallBack);
            if (opts != null) {
                iMQTTToken = client.connectWithResult(opts);
                publishMSG(client, TOPIC,"010101".getBytes(), QoS, pub_isRetained);
                iMQTTToken.setActionCallback(synchCallBack);
                if (client.isConnected()) {
                    System.out.println("Client CONNECTED.");
                    publishMSG(client, TOPIC,"010101".getBytes(), QoS, pub_isRetained);
                }
            }
        }
    ....
    ....
    ....
    ....
IMqttToken iMQTTToken = new IMqttToken() {

    @Override
    public void waitForCompletion(long arg0) throws MqttException {
        // TODO Auto-generated method stub
        System.out.println("@waitForCompletion(): waiting " + (arg0 * 1000) + " seconds for connection to be established.");
    }

    @Override
    public void waitForCompletion() throws MqttException {
        // TODO Auto-generated method stub
        System.out.println("@waitForCompletion(): waiting for connection to be established.");
    }

    @Override
    public void setUserContext(Object arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void setActionCallback(IMqttActionListener arg0) {
        // TODO Auto-generated method stub
        arg0.onSuccess(iMQTTToken);
        //System.out.println(" " + arg0.onSuccess());
        //System.out.println(" " + arg0.onSuccess(iMQTTToken));
        iMQTTToken.setActionCallback(synchCallBack);
    }

    @Override
    public boolean isComplete() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public Object getUserContext() {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public String[] getTopics() {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public boolean getSessionPresent() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public MqttWireMessage getResponse() {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public int getMessageId() {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public int[] getGrantedQos() {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public MqttException getException() {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public IMqttAsyncClient getClient() {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public IMqttActionListener getActionCallback() {
        // TODO Auto-generated method stub
        return null;
    }
};

IMqttActionListener synchCallBack = new IMqttActionListener() {

    @Override
    public void onSuccess(IMqttToken arg0) {
        // TODO Auto-generated method stub
        System.out.println("@onSuccess: Connection Successful.");
    }

    @Override
    public void onFailure(IMqttToken arg0, Throwable arg1) {
        // TODO Auto-generated method stub
        System.out.println("@onFailure: Connection Failed.");
        setViewEnableState(Bconnect, true);
    }
};

MqttCallback AsynchCallBack = new MqttCallback() {

    @Override
    public void messageArrived(String topic, MqttMessage msg) throws Exception {
        // TODO Auto-generated method stub
        System.out.println("@messageArrived: Message Delivered.");
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {
        // TODO Auto-generated method stub
        System.out.println("@deliveryComplete: Delivery Completed.");
    }

    @Override
    public void connectionLost(Throwable thrw) {
        // TODO Auto-generated method stub
        System.out.println("@Connection Lost: Connection Lost.");
        setViewEnableState(Bconnect, true);
    }
};

新客户:

    MqttConnectOptions opts = new MqttConnectOptions();
    opts.setCleanSession(CS);
    opts.setKeepAliveInterval(KATimer);
    HashMap<Integer, WILL> LWTData = WILLFactory.newWILL("LWT", "LWT MS".getBytes(), 1, false);
    opts.setWill(LWTData.get(0).getWILLTopic(), 
            LWTData.get(0).getWILLPayLoad(), 
            LWTData.get(0).getWILLQoS(), 
            LWTData.get(0).isWILLRetained());

    client = MQTTClientFactory.newClient(IP, PORT, clientID);

    if (client != null) {
        System.out.println("client is not null");

        client.setCallback(AsynchCB);
        IMqttToken token = client.connectWithResult(opts);

        if (client.isConnected()) {
            System.out.println("Client is Connected");

            token.setActionCallback(new IMqttActionListener() {

                public void onSuccess(IMqttToken arg0) {
                    // TODO Auto-generated method stub
                    System.out.println("synchCB->@onSuccess(): Connection Successful");

                    try {
                        client.subscribe(TOPIC, QoS);
                    } catch (MqttException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    try {
                        client.disconnect();
                    } catch (MqttException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }

                public void onFailure(IMqttToken arg0, Throwable arg1) {
                    // TODO Auto-generated method stub
                    System.out.println("synchCB->@onFailure(): Connection Failed");
                }
            });
        }else {
            System.out.println("client is not connected");
        }
    }else {
        System.out.println("client = null");
    }

异步回调:

/**
 * Asynchronous Callback to inform the user about events that might happens Asynchronously. If it is not used, any pending 
 * messages destined to the client would not be received.
 */
private static MqttCallback AsynchCB = new MqttCallback() {

    public void messageArrived(String topic, MqttMessage msg) throws Exception {
        // TODO Auto-generated method stub
        System.out.println("AsynchCB->@messageArrived(): ");

        System.out.println("Topic: " + topic);
        System.out.println("MSG: " + msg.toString());

    }

    public void deliveryComplete(IMqttDeliveryToken arg0) {
        // TODO Auto-generated method stub
        System.out.println("AsynchCB->@deliveryComplete(): ");
    }

    public void connectionLost(Throwable arg0) {
        // TODO Auto-generated method stub
        System.out.println("AsynchCB->@connectionLost(): ");
    }
};

最佳答案

您的计算机上驻留的客户端,它处理您的回调,传出端口可能被计算机的防火墙阻止。

关于java - MqttClient 对象的同步和异步接口(interface)不起作用,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/27185591/

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