B4J Library MqttBroker

jMqttBroker library is based on the moquette open source project: https://github.com/andsel/moquette

It implements a MQTT broker. If you are not familiar with MQTT then start with this tutorial: https://www.b4x.com/android/forum/threads/59471/#content

The broker is like a "black box". It is responsible for managing the clients and routing the messages.

With this library you can embed the broker inside your app instead of using an external broker.

Note that this library can also be used with B4A. You can turn any Android or Linux board to a MQTT broker.
With B4A you need to add the INTERNET permission with the manifest editor:

AddPermission(android.permission.INTERNET)

Using this library is simple:

Sub Process_Globals
   Dim broker As MqttBroker
End Sub

Sub AppStart (Args() As String)
   broker.Initialize("", 51041) 'first parameter is the event name. It is currently not used.
   broker.DebugLog = True
   broker.Start
   StartMessageLoop 'Non-UI app
End Sub

jMQTTBroker V1: www.b4x.com/b4j/files/moqueutte.zip

jMQTTBroker v2 based on moquette v0.12 (December 2018) is available here: www.b4x.com/b4j/files/jMqttBroker2.zip
Unlike v1, the new version is not compatible with B4A.

Updates:

V2.02 - Fixes a compatibility issue with B4JPackager 11.
V2.01 - Changes an internal auto-flush timeout that caused delays.

 

[b4auser1]

How to setup Passwords file, ACL files, SSL as it is described in the
http://andsel.github.io/moquette/ ?

 

[Erel]

You can set a single user name and password with broker.SetUserAndPassword.

The other authorization methods are not exposed.

 

[Erel]

V1.01 was released (same link as before). It fixes an issue related to the LastWill message.

 

[b4auser1]

Is it possible to setup SSL ?

 

[Erel]

Currently no.

 

[woniol]

Hi,
I tried it with jMQTT client, and every time i publish a message from the client i get this in the server logs:

Serious error processing the message org.eclipse.moquette.proto.messages.PubAckMessage@58121280 for session [clientID: fsdfsdf]org.eclipse.moquette.server.netty.NettyChannel@3ad9b9ea

Is it normal, or am I doing something wrong?

 

[Erel]

I've just posted a full B4A + B4J + B4i example that you can try: https://www.b4x.com/android/forum/threads/b4x-mqtt-chat-room.61568/

Set the QOS to 0 and see whether it solves this issue.

 

[freedom2000]

thank you for this --> very good features for home automation

 

[woniol]

I've just posted a full B4A + B4J + B4i example that you can try: https://www.b4x.com/android/forum/threads/b4x-mqtt-chat-room.61568/

Set the QOS to 0 and see whether it solves this issue.

Setting QOS to 0 on the publish side helped.
Thanks.

 

[woniol]

What's the problem with QOS 1 and QOS 2, can't we use it with b4j broker?

 

[Erel]

Not sure why it doesn't work for you with QOS 1 or 2. It works here when I test it (slower but works).

 

[Erel]

I do see this error message in the logs though everything seems to work fine. It looks like a problem inside the moquette project.

 

[woniol]

One more thing,
although i set credentials on for the broker with

broker.SetUserAndPassword("user","pass")

I can connect to it with

client.Connect

When I use

client.Connect2(MqttConnectOptions)

, credentials are veryfied.

 

[Erel]

This is indeed a bug. It is fixed in v1.03 (same link as before).

 

[woniol]

Credentials work fine now, thanks for the fix.

Here is a short example of the problems with setting QOS.
It looks like it has something to do with Subscribe QOS, try to change it to 1 or 2

In all Subscribe QOS settings, when i publish a message with QOS2 it is published with payload lenght = 0 (see the example)

 

[Erel]

The problem is inside the open source project. For now you should use QOS 0 or 1.

 

[woniol]

Ok, undertood, thanks for the explanation.

 

[fishwolf]

jMqttBroker library is based on the moquette open source project: https://github.com/andsel/moquette

It implements a MQTT broker. If you are not familiar with MQTT then start with this tutorial: https://www.b4x.com/android/forum/threads/59471/#content

The broker is like a "black box". It is responsible for managing the clients and routing the messages.

With this library you can embed the broker inside your app instead of using an external broker.

Note that this library can also be used with B4A. You can turn any Android or Linux board to a MQTT broker.

Using this library is simple:

Sub Process_Globals
   Dim broker As MqttBroker
End Sub

Sub AppStart (Args() As String)
   broker.Initialize("", 51041) 'first parameter is the event name. It is currently not used.
   broker.Start
   StartMessageLoop 'Non-UI app
End Sub

Download link: www.b4x.com/b4j/files/moqueutte.zip

I have done a No-UI application B4J with broken library and 3 lines of code.

I'm try to use the B4A chat example and the connection failed.

any suggestion?

 

[Erel]

The broker library should work in UI app. If you aren't able to solve it then please start a new thread and provide more information.