mqtt broker on android

Introduction

On android device, we often use paho mqtt client to setup mqtt client.

If you want android device to become a mqtt broker. you can use Moquette MQTT broker.

This article is about how to setup mqtt broker on android device with moqutte.

Android app settings

Following settings is not mandatory, it’s just the pre-settings of the sample app.

language: Kotlin

minSdkVersion 26
minSdkVersion 29

multiDexEnabled true

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

<uses-permission android:name="android.permission.INTERNET" />

Steps

Add dependency

Add dependency to app build.gradle.

dependencies {
    implementation 'io.moquette:moquette-broker:0.12.1'
}

Configure packagingOptions

Sync gradle, then you might got errors such as:

More than one file was found with OS independent path 'META-INF/io.netty.versions.properties'

More than one file was found with OS independent path 'META-INF/INDEX.LIST'

Exclude them in build.gradle of app:

android {
    ...
    packagingOptions {
        exclude 'META-INF/io.netty.versions.properties'
        exclude 'META-INF/INDEX.LIST'
    }
}

Start & stop server

private fun startMqttBroker() {
    val properties = Properties()
    properties.setProperty("host", "0.0.0.0")
    properties.setProperty("port", "1883")
    mqttBroker.startServer(properties)
}

private fun stopMqttBroker() {
    mqttBroker.stopServer()
}

It’s already ok for mqttBroker. If you want to make more detailed configurations, follow the next step.

Configure

Check the properties in mosquitto.conf, and set it to mqttBroker.

##############################################
#  Moquette configuration file.
#
#  The synthax is equals to mosquitto.conf
#
##############################################

port 1883

websocket_port 8080

host 0.0.0.0

#false to accept only client connetions with credentials
#true to accept client connection without credentails, validating only the one that provides
allow_anonymous true

#false to prohibit clients from connecting without a clientid.
#true to allow clients to connect without a clientid. One will be generated for them.
allow_zero_byte_client_id false

References

mqtt-broker-for-android