Android Question MQTT ZipException:incorrect header check error

[JOHN NG]

Hi

This is my code to receive message arrive of MQTT . But i getting java.util.zip.ZipException:incorrect header check error at line : ConvertBytesToObject . The reply message is "true" , "false"

Private Sub mqtt_MessageArrived (Topic As String, Payload() As Byte)
Dim obj As Object = serializator.ConvertBytesToObject(Payload)


If obj Is String Then
Dim s As String = obj
Select s
Case "false"
Msgbox("Fail to turn off ","Message")
Case "true"
Msgbox("Success turn off ","Message")
End Select
End If

End Sub

 

[Peter Simpson]

Have you looked at this https://www.b4x.com/android/forum/threads/jmqtt-official-android-mqtt-client.59497/#content

 

[Erel]

1. You should never use Msgbox to debug your app. Switch to Log.

2. Please use [code]code here...[/code] tags when posting code.

3. Where is the code that sends the messages?

 

[JOHN NG]

Hi @Erel

This is my code to send MQTT . MQTT broker and client able to receive the message . But B4a can't receive the reply .

Private serverURI As String = "tcp://111.111.111.111:1111"
  
   If mqtt.Connected == False Then
       Log("Client not connected")
       mqtt.Initialize("mqtt", serverURI, Rnd(0, 999999999) & DateTime.Now)
       Dim mo As MqttConnectOptions
       mo.Initialize("", "")
       mqtt.Connect2(mo)
       Log("Client connected")
   End If

   If mqtt.Connected == True Then
      mqtt.Subscribe("/Testing/Reply", 0)
       mqtt.Publish2("/Testing/123",Array As Byte(0),mqtt.QOS_2_EXACTLY_ONCE,False)
   'mqtt.Close
   End If

 

[OliverA]

MQTT broker and client able

What broker? What client?

mqtt.Publish2("/Testing/123",Array As Byte(0),mqtt.QOS_2_EXACTLY_ONCE,False)

You're publishing a 1 byte message, how is this

serializator.ConvertBytesToObject(Payload)

supposed to handle that correctly? Should you not serialize it before publishing?

 

[Erel]

I will add: you must use B4XSerializator in both the sending side and the receiving side.