我正在使用MQTT paho java库尝试使用qos2将消息发布到主题。但这个话题并没有收到它。我已经遵循了所有要求，例如clean session = false，同样的客户端ID ......，但它似乎没有用。它仅适用于qos 0＆amp;谁能告诉我我的代码有什么问题？
private int brokerPortNumber = 1883;
private MqttPersistence usePersistence = null;
private boolean cleanStart = false;
private int[] qualitiesOfService = { 2 } ;
subscribeToTopic(uid);
public void publishMessageToTopic(String message, String uid)
{
Boolean retained = false;
if (isAlreadyConnected() == false) {
Log.d(TAG, "mqtt, Unable to publish as we are not connected");
Toast.makeText(this, "No internet connection", Toast.LENGTH_LONG).show();
}
else
{
try
{
// Log.d(TAG, "MQTT Publish Message Rcvd: " + message);
// String[] tps = { topicName };
// MqttPayload msg = new MqttPayload(message.getBytes());
byte[] msg = message.getBytes();
String value3=uid;
mqttClient.publish(uid, msg, 2, false);
}
catch (MqttNotConnectedException e)
{
Log.e("mqtt", "subscribe failed - MQTT not connected", e);
Toast.makeText(this, "MQTT not connected", Toast.LENGTH_LONG).show();
}
catch (IllegalArgumentException e)
{
Log.e("mqtt", "subscribe failed - illegal argument", e);
}
catch (MqttException e)
{
Log.e("mqtt", "subscribe failed - MQTT exception", e);
}
}
}
/*
* Send a request to the message broker to be sent messages published with
* the specified topic name. Wildcards are allowed.
*/
private void subscribeToTopic(String topicName)
{
boolean subscribed = false;
if (isAlreadyConnected() == false)
{
// quick sanity check - don't try and subscribe if we
// don't have a connection
Log.e("mqtt", "Unable to subscribe as we are not connected");
}
else
{
try
{
String[] topics = { topicName };
mqttClient.subscribe(topics, qualitiesOfService);
subscribed = true;
}
catch (MqttNotConnectedException e)
{
Log.e("mqtt", "subscribe failed - MQTT not connected", e);
}
catch (IllegalArgumentException e)
{
Log.e("mqtt", "subscribe failed - illegal argument", e);
}
catch (MqttException e)
{
Log.e("mqtt", "subscribe failed - MQTT exception", e);
}
}
if (subscribed == false)
{
broadcastServiceStatus("Unable to subscribe");
//notifyUser("Unable to subscribe", "MQTT", "Unable to subscribe");
}
}
public void publishArrived(String topic, byte[] payloadbytes, int qos, boolean retained)
{
// we protect against the phone switching off while we're doing this
// by requesting a wake lock - we request the minimum possible wake
// lock - just enough to keep the CPU running until we've finished
PowerManager pm = (PowerManager) getSystemService(POWER_SERVICE);
WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "MQTT");
wl.acquire();
//
// I'm assuming that all messages I receive are being sent as strings
// this is not an MQTT thing - just me making as assumption about what
// data I will be receiving - your app doesn't have to send/receive
// strings - anything that can be sent as bytes is valid
String messageBody = new String(payloadbytes);
}
} catch (JSONException e) {
e.printStackTrace();
}
//
// inform the user (for times when the Activity UI isn't running)
// that there is new data available
// notifyUser("New message received", messageBody);
// receiving this message will have kept the connection alive for us, so
// we take advantage of this to postpone the next scheduled ping
scheduleNextPing();
// we're finished - if the phone is switched off, it's okay for the CPU
// to sleep now
wl.release();
}
//Connection to broker
private int brokerPortNumber = 1883;
private MqttPersistence usePersistence = null;
private boolean cleanStart = false;
private int[] qualitiesOfService = { 2 } ;
subscribeToTopic(uid);
public void publishMessageToTopic(String message, String uid)
{
Boolean retained = false;
if (isAlreadyConnected() == false) {
Log.d(TAG, "mqtt, Unable to publish as we are not connected");
Toast.makeText(this, "No internet connection", Toast.LENGTH_LONG).show();
}
else
{
try
{
// Log.d(TAG, "MQTT Publish Message Rcvd: " + message);
// String[] tps = { topicName };
// MqttPayload msg = new MqttPayload(message.getBytes());
byte[] msg = message.getBytes();
String value3=uid;
mqttClient.publish(uid, msg, 2, false);
}
catch (MqttNotConnectedException e)
{
Log.e("mqtt", "subscribe failed - MQTT not connected", e);
Toast.makeText(this, "MQTT not connected", Toast.LENGTH_LONG).show();
}
catch (IllegalArgumentException e)
{
Log.e("mqtt", "subscribe failed - illegal argument", e);
}
catch (MqttException e)
{
Log.e("mqtt", "subscribe failed - MQTT exception", e);
}
}
}
/*
* Send a request to the message broker to be sent messages published with
* the specified topic name. Wildcards are allowed.
*/
private void subscribeToTopic(String topicName)
{
boolean subscribed = false;
if (isAlreadyConnected() == false)
{
// quick sanity check - don't try and subscribe if we
// don't have a connection
Log.e("mqtt", "Unable to subscribe as we are not connected");
}
else
{
try
{
String[] topics = { topicName };
mqttClient.subscribe(topics, qualitiesOfService);
subscribed = true;
}
catch (MqttNotConnectedException e)
{
Log.e("mqtt", "subscribe failed - MQTT not connected", e);
}
catch (IllegalArgumentException e)
{
Log.e("mqtt", "subscribe failed - illegal argument", e);
}
catch (MqttException e)
{
Log.e("mqtt", "subscribe failed - MQTT exception", e);
}
}
if (subscribed == false)
{
broadcastServiceStatus("Unable to subscribe");
//notifyUser("Unable to subscribe", "MQTT", "Unable to subscribe");
}
}
public void publishArrived(String topic, byte[] payloadbytes, int qos, boolean retained)
{
// we protect against the phone switching off while we're doing this
// by requesting a wake lock - we request the minimum possible wake
// lock - just enough to keep the CPU running until we've finished
PowerManager pm = (PowerManager) getSystemService(POWER_SERVICE);
WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "MQTT");
wl.acquire();
//
// I'm assuming that all messages I receive are being sent as strings
// this is not an MQTT thing - just me making as assumption about what
// data I will be receiving - your app doesn't have to send/receive
// strings - anything that can be sent as bytes is valid
String messageBody = new String(payloadbytes);
}
} catch (JSONException e) {
e.printStackTrace();
}
//
// inform the user (for times when the Activity UI isn't running)
// that there is new data available
// notifyUser("New message received", messageBody);
// receiving this message will have kept the connection alive for us, so
// we take advantage of this to postpone the next scheduled ping
scheduleNextPing();
// we're finished - if the phone is switched off, it's okay for the CPU
// to sleep now
wl.release();
}
与经纪人的联系
private void defineConnectionToBroker(String brokerHostName)
{
String mqttConnSpec = "tcp://" + brokerHostName + "@" + brokerPortNumber;
try
{
// define the connection to the broker
mqttClient = MqttClient.createMqttClient(mqttConnSpec, usePersistence);
// register this client app has being able to receive messages
mqttClient.registerSimpleHandler(this);
}
catch (MqttException e)
{
// something went wrong!
mqttClient = null;
connectionStatus = MQTTConnectionStatus.NOTCONNECTED_UNKNOWNREASON;
//
// inform the app that we failed to connect so that it can update
// the UI accordingly
broadcastServiceStatus("Invalid connection parameters");
//
// inform the user (for times when the Activity UI isn't running)
// that we failed to connect
// notifyUser("Unable to connect", "MQTT", "Unable to connect");
}
}