MqttConnection：客户端未连接，因此不在Java中发送消息

分类：编程问答

如何解决MqttConnection：客户端未连接，因此不在Java中发送消息

我尝试使用mqtt paho发布主题或发布消息mqtt.fx，但是它显示消息I / MqttConnection：客户端未连接，所以未发送消息。我的英语不好，但我希望您理解我的问题。我工作了几个小时，但找不到任何解决方案。 这是主要活动：

  @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    pahoMqttClient = new PahoMqttClient();

    textMessage = (EditText) findViewById(R.id.textMessage);
    publishMessage = (Button) findViewById(R.id.publishMessage);

    subscribe = (Button) findViewById(R.id.subscribe);
    unSubscribe = (Button) findViewById(R.id.unSubscribe);

    subscribeTopic = (EditText) findViewById(R.id.subscribeTopic);
    unSubscribeTopic = (EditText) findViewById(R.id.unSubscribeTopic);
    client = pahoMqttClient.getMqttClient(getApplicationContext(),Constants.MQTT_BROKER_URL,Constants.CLIENT_ID);

    publishMessage.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String msg = textMessage.getText().toString().trim();
            if (!msg.isEmpty()) {
                try {
                    pahoMqttClient.publishMessage(client,msg,1,Constants.PUBLISH_TOPIC);
                } catch (MqttException e) {
                    e.printStackTrace();
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }
            }
        }
    });

    subscribe.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String topic = subscribeTopic.getText().toString().trim();
            if (!topic.isEmpty()) {
                try {
                    pahoMqttClient.subscribe(client,topic,1);
                } catch (MqttException e) {
                    e.printStackTrace();
                }
            }
        }
    });
    unSubscribe.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String topic = unSubscribeTopic.getText().toString().trim();
            if (!topic.isEmpty()) {
                try {
                    pahoMqttClient.unSubscribe(client,topic);
                } catch (MqttException e) {
                    e.printStackTrace();
                }
            }
        }
    });

    Intent intent = new Intent(MainActivity.this,MqttMessageService.class);
    startService(intent);
}

}

这是我的客户代码：

public class PahoMqttClient {

private static final String TAG = "PahoMqttClient";
private MqttAndroidClient mqttAndroidClient;

public MqttAndroidClient getMqttClient(Context context,String brokerUrl,String clientId) {

    mqttAndroidClient = new MqttAndroidClient(context,brokerUrl,clientId);
    try {
        IMqttToken token = mqttAndroidClient.connect(getMqttConnectionOption());
        token.setActionCallback(new IMqttActionListener() {
            @Override
            public void onSuccess(IMqttToken asyncActionToken) {
                mqttAndroidClient.setBufferOpts(getDisconnectedBufferOptions());
                Log.d(TAG,"Success");
            }

            @Override
            public void onFailure(IMqttToken asyncActionToken,Throwable exception) {
                Log.d(TAG,"Failure " + exception.toString());
            }
        });
    } catch (MqttException e) {
        e.printStackTrace();
    }

    return mqttAndroidClient;
}

public void disconnect(@NonNull MqttAndroidClient client) throws MqttException {
    IMqttToken mqttToken = client.disconnect();
    mqttToken.setActionCallback(new IMqttActionListener() {
        @Override
        public void onSuccess(IMqttToken iMqttToken) {
            Log.d(TAG,"Successfully disconnected");
        }

        @Override
        public void onFailure(IMqttToken iMqttToken,Throwable throwable) {
            Log.d(TAG,"Failed to disconnected " + throwable.toString());
        }
    });
}

@NonNull
private DisconnectedBufferOptions getDisconnectedBufferOptions() {
    DisconnectedBufferOptions disconnectedBufferOptions = new DisconnectedBufferOptions();
    disconnectedBufferOptions.setBufferEnabled(true);
    disconnectedBufferOptions.setBufferSize(100);
    disconnectedBufferOptions.setPersistBuffer(false);
    disconnectedBufferOptions.setDeleteOldestMessages(false);
    return disconnectedBufferOptions;
}

@NonNull
private MqttConnectOptions getMqttConnectionOption() {
    MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
    mqttConnectOptions.setCleanSession(false);
    mqttConnectOptions.setAutomaticReconnect(true);
    //mqttConnectOptions.setWill(Constants.PUBLISH_TOPIC,"I am going offline".getBytes(),true);
    //mqttConnectOptions.setUserName("ngbllzzy");
    //mqttConnectOptions.setPassword("WtjhZKl3OPoK".toCharArray());
    return mqttConnectOptions;
}


public void publishMessage(@NonNull MqttAndroidClient client,@NonNull String msg,int qos,@NonNull String topic)
        throws MqttException,UnsupportedEncodingException {
    byte[] encodedPayload = new byte[0];
    encodedPayload = msg.getBytes("UTF-8");
    MqttMessage message = new MqttMessage(encodedPayload);
    message.setId(320);
    message.setRetained(true);
    message.setQos(qos);
    client.publish(topic,message);
}

public void subscribe(@NonNull MqttAndroidClient client,@NonNull final String topic,int qos) throws MqttException {
    IMqttToken token = client.subscribe(topic,qos);
    token.setActionCallback(new IMqttActionListener() {
        @Override
        public void onSuccess(IMqttToken iMqttToken) {
            Log.d(TAG,"Subscribe Successfully " + topic);
        }

        @Override
        public void onFailure(IMqttToken iMqttToken,Throwable throwable) {
            Log.e(TAG,"Subscribe Failed " + topic);

        }
    });
}

public void unSubscribe(@NonNull MqttAndroidClient client,@NonNull final String topic) throws MqttException {

    IMqttToken token = client.unsubscribe(topic);

    token.setActionCallback(new IMqttActionListener() {
        @Override
        public void onSuccess(IMqttToken iMqttToken) {
            Log.d(TAG,"UnSubscribe Successfully " + topic);
        }

        @Override
        public void onFailure(IMqttToken iMqttToken,"UnSubscribe Failed " + topic);
        }
    });
}

} 在这里，我为经纪人URL，客户ID和发布主题创建了单独的类。

 public class Constants {

public static final String MQTT_BROKER_URL = "tcp://127.0.0.1:1883";

public static final String PUBLISH_TOPIC = "test";

public static final String CLIENT_ID = "ef9c9a7c92d04effaead3f22227703ae";

} 

And finally here it is message service class:
   


public class MqttMessageService extends Service {

private static final String TAG = "MqttMessageService";
private PahoMqttClient pahoMqttClient;
private MqttAndroidClient mqttAndroidClient;

public MqttMessageService() {
}

@Override
public void onCreate() {
    super.onCreate();
    Log.d(TAG,"onCreate");
    pahoMqttClient = new PahoMqttClient();
    mqttAndroidClient = pahoMqttClient.getMqttClient(getApplicationContext(),Constants.CLIENT_ID);

    mqttAndroidClient.setCallback(new MqttCallbackExtended() {
        @Override
        public void connectComplete(boolean b,String s) {

        }

        @Override
        public void connectionLost(Throwable throwable) {

        }

        @Override
        public void messageArrived(String s,MqttMessage mqttMessage) throws Exception {
            setMessageNotification(s,new String(mqttMessage.getPayload()));
        }

        @Override
        public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {

        }
    });
}

@Override
public int onStartCommand(Intent intent,int flags,int startId) {
    Log.d(TAG,"onStartCommand");
    return START_STICKY;
}

@Override
public IBinder onBind(Intent intent) {
    // TODO: Return the communication channel to the service.
    throw new UnsupportedOperationException("Not yet implemented");
}

@Override
public void onDestroy() {
    super.onDestroy();
    Log.d(TAG,"onDestroy");
}

private void setMessageNotification(@NonNull String topic,@NonNull String msg) {
    NotificationCompat.Builder mBuilder =
            new NotificationCompat.Builder(this)
                    .setSmallIcon(R.drawable.ic_message_black_24dp)
                    .setContentTitle(topic)
                    .setContentText(msg);
    Intent resultIntent = new Intent(this,MainActivity.class);

    TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
    stackBuilder.addParentStack(MainActivity.class);
    stackBuilder.addNextIntent(resultIntent);
    PendingIntent resultPendingIntent =
            stackBuilder.getPendingIntent(0,PendingIntent.FLAG_UPDATE_CURRENT);
    mBuilder.setContentIntent(resultPendingIntent);
    NotificationManager mNotificationManager =
            (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    mNotificationManager.notify(100,mBuilder.build());
}

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