B4A Library MQTT - MQ Telemetry Transport for B4A

This library was made based on MQTT Protocol


Installation instructions:
- Copy the .xml and .jar(s) files to your custom libraries folder
- Select in your REFERENCED LIBRARIES

Version history:
V1.0.0 (First public release - Donationware):
- Initial version

V1.0.2 (Release - Donationware):
- Implement method to get independence of threads

V1.0.4 (Release - Donationware):
- Implement method to subscribe a topic with QoS

V1.0.5 (Release - Donationware):
- Now can be used isConnected method "BEFORE" the first connection

V1.0.6 (Release - Donationware):
- not published

V1.0.7 (Release - Donationware):
- New methods: Publish2, Subscribe3, Subscribe4
This new methods return the token, then after when arrived or publish the messages, you can compare

MQTT
Author: Alberto Iglesias - alberto@visualnet.inf.br
Version: 1.07

• MQTT
  Events:
  • connectionlost ( )
  • deliverycomplete (Token As String)
  • messageArrived (Topic As String, Message As String)
  • onConnect (Status as boolean As )
  • onDisconnect (Status as boolean As )
  • onInitialized ( )
  Fields:
  • CleanSession As Boolean
  • JavaDebug As Boolean
  • KeepAliveInterval As Int
  • QoS_AtLeastOnce As Int
  • QoS_AtMostOnce As Int
  • QoS_ExactlyOnce As Int
  • generatedClientId As String
  Methods:
  • About As String
  • Connect (broker As String, ClientID As String, Username As String, Password As String) As Boolean
  • Disconnect As Boolean
  • Initialize (eventname As String)
  • Publish (Topic As String, Message As String, Qos As Int, Retained As Boolean)
  • Publish2 (Topic AsString, Message AsString, Qos AsInt, Retained AsBoolean)
    
  • Subscribe (Topic As String)
  • Subscribe2 (Topic As String, QoS as int)
    
  • Subscribe3 (Topic As String)
    
  • Subscribe4 (Topic As String, QoS as int))
    
  • Unsubscribe (Topic As String)
  • Version As String
  • isConnected As Boolean
  Permissions:
  • android.permission.ACCESS_WIFI_STATE
  • android.permission.INTERNET

How works the MQTT protocol

Communication Infrastructure

References:
http://mqtt.org/
http://public.dhe.ibm.com/software/dw/webservices/ws-mqtt/mqtt-v3r1.html
Mosquitto Broker: http://mosquitto.org/



* This version is fully functional, the only one difference is when publishing a message the text "Donationware" is delivery with your message.
Please consider a simple €10 donation and I send to you the Library without "Donationware" text in a publish method.

Already available in B4J too:
https://www.b4x.com/android/forum/threads/mqtt-mq-telemetry-transport-for-b4j.48184/

Already available in B4i too:
https://www.b4x.com/android/forum/threads/mqtt-mq-telemetry-transport-for-b4i.50036/

 

[Alberto Iglesias]

No. I say in our app, WE do a routine to do this...

 

[coslad]

So, have you written a mtqq broker? Wonderful ! If you in the future will share the code with us should be more useful

 

[jndaniels1]

HI Alberto.
I was referred to your post here by another user - I am (was, is) looking at rabbitMQ. And was actively trying to integrate it. But alas you have created a B4A lib to save my day.

I have a particular sensitive project that message queueing is going to be an absolute necessary --- what i am curious about is a few things.
speed ? 10s, 100s, millions per sec?
clusterable?
what if my broker crashes or reboots, will it kill the cluster or requeue messages (if set so) ?
and what about the client (app, b4a or other) keeps disconnecting - does it handle reconnects and picks up where it left off?

Thank you for your time in advance!
Kind Regards
JEFFD

 

[JakeBullet70]

HI Alberto.

I just donated. Do I need to donate 2 times as I need the lib for b4a and b4j.

Thanks

 

[woniol]

Does the B4J version follow B4A version?
Is there B4J 1.05 available?

 

[jndaniels1]

Hi Alberto or Erel
Ran into a bit of an error I dont know how to get around.

I am using both your libraries MQTT and XMPP --- Using the example from the MQTT zip and just adding the XMPP library produces the error below.

I simply added in the process_globals
Dim oXmpp as XMPP

Without the line the MQTT example works perfectly, installs and runs.
Any help would be super great!
Thanks!

Convert byte code - optimized dex.      Error
UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already added: Lcom/visualnet/mqtt;
    at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:122)
    at com.android.dx.dex.file.DexFile.add(DexFile.java:161)
    at com.android.dx.command.dexer.Main.processClass(Main.java:732)
    at com.android.dx.command.dexer.Main.processFileBytes(Main.java:673)
    at com.android.dx.command.dexer.Main.access$300(Main.java:83)
    at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:602)
    at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:284)
    at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:166)
    at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:144)
    at com.android.dx.command.dexer.Main.processOne(Main.java:632)
    at com.android.dx.command.dexer.Main.processAllFiles(Main.java:510)
    at com.android.dx.command.dexer.Main.runMonoDex(Main.java:280)
    at com.android.dx.command.dexer.Main.run(Main.java:246)
    at com.android.dx.command.dexer.Main.main(Main.java:215)
    at com.android.dx.command.Main.main(Main.java:106)
warning: Ignoring InnerClasses attribute for an anonymous inner class
(org.eclipse.paho.client.mqttv3.persist.MqttDefaultFilePersistence$1) that doesn't come with an
associated EnclosingMethod attribute. This class was probably produced by a
compiler that did not target the modern .class file format. The recommended
solution is to recompile the class from source, using an up-to-date compiler
and without specifying any "-target" type options. The consequence of ignoring
this warning is that reflective operations on this class will incorrectly
indicate that it is *not* an inner class.
warning: Ignoring InnerClasses attribute for an anonymous inner class
(org.eclipse.paho.client.mqttv3.persist.MqttDefaultFilePersistence$2) that doesn't come with an
associated EnclosingMethod attribute. This class was probably produced by a
compiler that did not target the modern .class file format. The recommended
solution is to recompile the class from source, using an up-to-date compiler
and without specifying any "-target" type options. The consequence of ignoring
this warning is that reflective operations on this class will incorrectly
indicate that it is *not* an inner class.
1 error; aborting
    Optimized dexer failed. Switching to Standard dexer.

Update:

I found in the xmpp.jar is a mqtt.class - removing the mqtt.class resolves the error. Just remember to backup your original xmpp.jar.

Cheers!

 

[Alberto Iglesias]

I will check right now, wait please!

 

[Alberto Iglesias]

Hey Jeff,

I fix this bug and post in the forum with version 1.0.3 and send to your email the full version...

Thanks

Alberto

 

[coslad]

Hi Alberto, do you know if is there a way to connect a vb6 application over mqtt ?

 

[Alberto Iglesias]

I thing in VB6 the correct name to your found MQTT is MQ Series, the old way to connect to the brokers.

look this examples: http://www.capitalware.com/pc_win_code_vb.html

 

[lemonisdead]

@Alberto Iglesias : referring from your message from Friday. How will you manage the updating to your registered users please ?

 

[Alberto Iglesias]

you refer about my libraries updates?

I have a control by paypal emails, and when I create a new version, I know who buy what, and then I send new versions

 

[coslad]

Thanks Alberto

 

[klarsys]

@Alberto Iglesias,

How do I set Last Will Testament?

 

[Alberto Iglesias]

Hey klarsys,

This library MQTT for B4A is based in Paho Library, and this library not have the properties Last Testament, look:

http://www.eclipse.org/paho/files/android-javadoc/index.html

 

[klarsys]

Setting will has to be done while connecting, through MqttConnectOptions:

http://www.eclipse.org/paho/files/javadoc/org/eclipse/paho/client/mqttv3/MqttConnectOptions.html

Refer setWill methods.

 

[Alberto Iglesias]

huuummm, it´s an important information... thanks!

i will include this method and soon I publish new version

 

[Alberto Iglesias]

Hey klarsys,

Can you try the version with setWill?

Follow is the version 1.0.6 beta with this feature.

Thanks for your help

Obs: Put your setWill options before connect to broker.

 

[klarsys]

It seems to be working!

Is this a usable version or will you upload another library?

 

[Alberto Iglesias]

yes, its usable.

It´s a donationware, but full operational