basicSample losing connection about paho.mqtt.android

[hannesa2]

Indeed, this lines are probably crap

paho.mqtt.android/basicSample/src/main/java/paho/mqtt/java/example/PahoExampleActivity.java

Lines 151 to 157 in a66af73

	// THIS DOES NOT WORK!
	mqttAndroidClient.subscribe(subscriptionTopic, 0, new IMqttMessageListener() {
	@Override
	public void messageArrived(String topic, MqttMessage message) {
	Log.d("Message arrived", topic + " : " + new String(message.getPayload()));
	}
	});

Anyway, I assume this is the main reason https://developer.android.com/about/versions/oreo/background.html
Here is the discussion eclipse/paho.mqtt.android#281

I would love when someone would implement a solution with https://developer.android.com/reference/android/app/job/JobScheduler.html . I would approve immediate

[JiriBilek]

Thanks for the reply. I didn't have an idea of the changes from Android 8 on.
It seems to me now that we can forget about long time TCP connections and about a reliable and instant MQTT transfer as well :(

[hannesa2]

Yes, this is the biggest problem in this library. Maybe I will fix it in the next few days, but I promise nothing

There is no reason to give up that early. You can switch back to
targetSdkVersion 24 then I expect to work properly.

But with this you can't publish to Google play store anymore

[hannesa2]

The thing is how to test it in Espresso test this background service behavior ?

[hannesa2]

@JiriBilek Your have to help me.

I following your connection String serverUri = "tcp://broker.hivemq.com:1883";

Does this works for you, or is it my network connection ? (I'm on vacation, and maybe the port it locked in my hotel)

[JiriBilek]

In your example, I had to add to the manifest more privileges to be able to connect:

    <!-- Permissions the Application Requires -->
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.WAKE_LOCK" />

[hannesa2]

In your example,

It's the example, not mine 😉 I just try to keep this library alive.

Please see #84 This solves only the init crash.
And yes there are too less permission, and unfortunately it's doesn't show any error when it's missing 👎

[JiriBilek]

I tried the example on Android 5.1 and it lost the connection as well.

[hannesa2]

I try to reproduce it, but till now I failed.

This looks not that bad.

How does it looks like on your side ?

[JiriBilek]

It looks the same. Between "The Connection was list" and "Reconnected" is losing the data from the broker.

The last line is confusing - failed connection because already connected. Weird.

I use QoS 0 as I my intention is to know about the event asap. I am monitoring a beehive (bumblebees, actually).

[hannesa2]

my intention is to know about the event asap

It has the touch of eclipse/paho.mqtt.android#281 (comment) Solution 1 with forground services You battery will be empty sooner, but everything has a price

Anyway I tried to introduce a test to capture the error case with #98 and #96 and to be honest I need help here to first have 1 #reproduce able issue, then (only after this) I can look for a 2 #solution.

For a better understanding it comes with screenshots of test case

I'm stuck on 1 #reproduce able issue. You are warmly welcome to jump into this.

[JiriBilek]

Yes, I read the comment about foreground services. It may solve my problem. It'll take me time as I must study the android services first. Until now, I took the paho.mqtt library as such and have not studied the internals in it.

As to the tests, I want to help but I don't understand what should I do.

[hannesa2]

As to the tests, I want to help but I don't understand what should I do.

I need to know, how to reproduce it.

Btw, the BasicDemo can send a message, but never receive it. -wtf-

[hannesa2]

Between "The Connection was list" and "Reconnected" is losing the data from the broker.

Did you changed the qos (quality of service) ? Maybe it helps.
Btw, when you do your changes in a branch of your fork, I could at least follow what you did

[JiriBilek]

Ok, I must leave now but in the afternoon I'll fork the repo and play with the qos.

[JiriBilek]

I forked the repo, made necessary changes (JiriBilek@8eda6ae) and run it. It run without losing the connection for 30 minutes while the phone was connected to the usb for the whole time. Shortly after disconnecting the usb cable, it lost the connection.

Still Android 5.1.

Edit: I realized that with the USB power, my old app runs fine and holds the connection like a charm. Next, I'll try the same on Android 10.

Edit2: I checked out the AwakeTest and run it. As long as the phone was connected to the PC (and charging), it held the connection. After plugging out, the connection was lost.

[HubKing]

Can my app receive the MQTT message even if the screen is turned off or my app is not the foreground app, with this library? The "basic sample" seems to be working, but that was with my app in the foreground with the screen on. My app would not be very useful if I have to keep the screen on and my app as the foreground app to receive the MQTT message.

If it is possible, would you add another simple sample project to show the incoming message in the system notification when the app is not the foreground app or the screen is turned off?

[hannesa2]

Without foreground service, you could give https://github.com/hannesa2/paho.mqtt.android/releases/tag/3.4.0-beta5 a try.
I uses Workmanager to avoid to keep device always on.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Please comment here if it is still valid so that we can reprioritize. Thank you!

[stale]

Closing this. Please reopen if you believe it should be addressed. Thank you for your contribution.