B4A Library jMQTT - Official Android MQTT client

The B4J jMQTT library is fully compatible with B4A: https://www.b4x.com/android/forum/threads/59472/#content

A tutorial about MQTT: [IoT] MQTT Protocol

Implementation of the same example is attached (you need to set the user name and password if you like to test it).

 

[Erel]

Can you post the full error message from the logs?

 

[haungmaojung]

Dear Erel,

I've found the problem.
Since Payload of Topic 'Last Will' is an UTF-8 PlainText, I just replace:
obj = serializator.ConvertBytesToObject(Payload)
msg = obj
to:
msg = BytesToString(Payload,0,Payload.Length,"UTF-8")

I'm sorry for my carelessness.
However, Thank you for your kindly response.

Best Regards,
Victor

 

[fransvlaarhoven]

Hallo Erel,

Assuming the broker has properly configured PSK, can the client make a connection using PSK?

Thanks

 

[Erel]

No. PSK is currently not supported.

 

[fransvlaarhoven]

No. PSK is currently not supported.

Oke, thanks

 

[reddtechnologies]

Hi,

I am getting this error.

LogCat connected to: emulator-5554
--------- beginning of main
--------- beginning of system
Copying updated assets files (1)
** Service (starter) Create **
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
java.lang.ExceptionInInitializerError
at anywheresoftware.b4j.objects.MqttAsyncClientWrapper.Initialize(MqttAsyncClientWrapper.java:42)
at b4a.example.main._activity_create(main.java:399)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:710)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:342)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:134)
at b4a.example.main.afterFirstLayout(main.java:102)
at b4a.example.main.access$000(main.java:17)
at b4a.example.main$WaitForLayout.run(main.java:80)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.util.MissingResourceException: Can't find resource for bundle 'org.eclipse.paho.client.mqttv3.internal.nls.logcat_en_US', key ''
at java.util.ResourceBundle.missingResourceException(ResourceBundle.java:238)
at java.util.ResourceBundle.getBundle(ResourceBundle.java:230)
at java.util.ResourceBundle.getBundle(ResourceBundle.java:139)
at org.eclipse.paho.client.mqttv3.logging.LoggerFactory.getLogger(LoggerFactory.java:73)
at org.eclipse.paho.client.mqttv3.MqttAsyncClient.<clinit>(MqttAsyncClient.java:79)
... 18 more
** Activity (main) Resume **
** Activity (main) Pause, UserClosed = true **
** Service (starter) Destroy **

 

[Erel]

Try it on a real device. Do you get the same error?

 

[reddtechnologies]

Here is what I get with a real device.

Logger connected to: MBX K200
--------- beginning of /dev/log/main
Copying updated assets files (1)
** Service (starter) Create **
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
java.lang.ExceptionInInitializerError
at anywheresoftware.b4j.objects.MqttAsyncClientWrapper.Initialize(MqttAsyncClientWrapper.java:42)
at b4a.example.main._activity_create(main.java:385)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:710)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:342)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:134)
at b4a.example.main.afterFirstLayout(main.java:102)
at b4a.example.main.access$000(main.java:17)
at b4a.example.main$WaitForLayout.run(main.java:80)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:788)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:604)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.util.MissingResourceException: Can't find resource for bundle 'org.eclipse.paho.client.mqttv3.internal.nls.logcat_en_US', key ''
at java.util.ResourceBundle.missingResourceException(ResourceBundle.java:238)
at java.util.ResourceBundle.getBundle(ResourceBundle.java:230)
at java.util.ResourceBundle.getBundle(ResourceBundle.java:139)
at org.eclipse.paho.client.mqttv3.logging.LoggerFactory.getLogger(LoggerFactory.java:73)
at org.eclipse.paho.client.mqttv3.MqttAsyncClient.<clinit>(MqttAsyncClient.java:79)
... 22 more
** Activity (main) Resume **
** Activity (main) Pause, UserClosed = true **
** Service (starter) Destroy **
** Service (starter) Create **
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
** Activity (main) Resume **
** Activity (main) Pause, UserClosed = true **
** Service (starter) Destroy **
** Service (starter) Create **
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
java.lang.ExceptionInInitializerError
at anywheresoftware.b4j.objects.MqttAsyncClientWrapper.Initialize(MqttAsyncClientWrapper.java:42)
at b4a.example.main._activity_create(main.java:385)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:710)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:342)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:134)
at b4a.example.main.afterFirstLayout(main.java:102)
at b4a.example.main.access$000(main.java:17)
at b4a.example.main$WaitForLayout.run(main.java:80)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:788)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:604)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.util.MissingResourceException: Can't find resource for bundle 'org.eclipse.paho.client.mqttv3.internal.nls.logcat_en_US', key ''
at java.util.ResourceBundle.missingResourceException(ResourceBundle.java:238)
at java.util.ResourceBundle.getBundle(ResourceBundle.java:230)
at java.util.ResourceBundle.getBundle(ResourceBundle.java:139)
at org.eclipse.paho.client.mqttv3.logging.LoggerFactory.getLogger(LoggerFactory.java:73)
at org.eclipse.paho.client.mqttv3.MqttAsyncClient.<clinit>(MqttAsyncClient.java:79)
... 22 more
** Activity (main) Resume **
** Activity (main) Pause, UserClosed = true **
** Service (starter) Destroy **
** Service (starter) Create **
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
java.lang.ExceptionInInitializerError
at anywheresoftware.b4j.objects.MqttAsyncClientWrapper.Initialize(MqttAsyncClientWrapper.java:42)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.shell.Shell.runVoidMethod(Shell.java:755)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:345)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:134)
at b4a.example.main.afterFirstLayout(main.java:102)
at b4a.example.main.access$000(main.java:17)
at b4a.example.main$WaitForLayout.run(main.java:80)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:788)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:604)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.util.MissingResourceException: Can't find resource for bundle 'org.eclipse.paho.client.mqttv3.internal.nls.logcat_en_US', key ''
at java.util.ResourceBundle.missingResourceException(ResourceBundle.java:238)
at java.util.ResourceBundle.getBundle(ResourceBundle.java:230)
at java.util.ResourceBundle.getBundle(ResourceBundle.java:139)
at org.eclipse.paho.client.mqttv3.logging.LoggerFactory.getLogger(LoggerFactory.java:73)
at org.eclipse.paho.client.mqttv3.MqttAsyncClient.<clinit>(MqttAsyncClient.java:79)
... 21 more
** Activity (main) Resume **
Error occurred on line: 34 (Main)
java.lang.NullPointerException
at anywheresoftware.b4j.objects.MqttAsyncClientWrapper.Connect2(MqttAsyncClientWrapper.java:69)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.shell.Shell.runVoidMethod(Shell.java:755)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:345)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:134)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:163)
at b4a.example.main.afterFirstLayout(main.java:108)
at b4a.example.main.access$000(main.java:17)
at b4a.example.main$WaitForLayout.run(main.java:80)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:788)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:604)
at dalvik.system.NativeStart.main(Native Method)

 

[reddtechnologies]

It actually fails at MQTT initialization. Android version is 4.4.2

 

[Erel]

Works fine here. Which version of B4A are you using?

 

[reddtechnologies]

I started with 3.8 full version but now I have also got latest trial version installed. So currently both versions installed. OS is Windows 10.

 

[Erel]

It will not work with v3.8. It will also won't work with the trial version.

 

[cxdzbl]

With demo, I modified my link, user name and password, but there was a link error, where I was wrong or not support Chinese users.


Sub Process_Globals
Private mqtt As MqttClient
Private mytopic As String
Private serializator As B4XSerializator
Type CircleData (x As Double, y As Double, clr As Int)
Private serverURI As String = "tcp://m13.cloudmqtt.com:11043"
End Sub

Sub Globals
Private Canvas1 As Canvas
Private lblStatus As Label
End Sub

Sub Activity_Create(FirstTime As Boolean)
If FirstTime Then
mqtt.Initialize("mqtt", serverURI, Rnd(0, 999999999) & DateTime.Now)
Dim mo As MqttConnectOptions
mo.Initialize("*******", "*******") 'Here I am my username and password
mqtt.Connect2(mo)
mytopic = "drawers/" & mqtt.ClientId
End If
Activity.LoadLayout("1")
Canvas1.Initialize(Activity)
End Sub

 

[Erel]

1. Please start a new thread for this question.
2. Please use [code]code here...[/code] tags when posting code.
3. Make sure to write the error message.