PubNub Java and Kotlin-based SDKs for Android

This is the official PubNub Kotlin SDK repository.

PubNub takes care of the infrastructure and APIs needed for the realtime communication layer of your application. Work on your app's logic and let PubNub handle sending and receiving data across the world in less than 100ms.

Get keys

You will need the publish and subscribe keys to authenticate your app. Get your keys from the Admin Portal.

Configure PubNub

1. Integrate the Kotlin SDK into your project:

   • for Maven, add the following dependency in your pom.xml:

     <dependency>
        <groupId>com.pubnub</groupId>
        <artifactId>pubnub-kotlin</artifactId>
        <version>10.4.7</version>
     </dependency>

   • for Gradle, add the following dependency in your gradle.build:

     implementation ("com.pubnub:pubnub-kotlin:10.0.0")

2. Configure your keys and create PubNub instance:

   val config = PNConfiguration.builder(UserId("myUserId"), "mySubKey") {
       publishKey = "myPubKey"
   }
   val pubnub = PubNub.create(config.build())

Add event listeners

// Create a subscription to a specific channel
val subscription = pubnub.channel("my_channel").subscription(SubscriptionOptions.receivePresenceEvents())

// Add a listener to the subscription for handling various event types
subscription.addListener(object : EventListener {
    override fun message(pubnub: PubNub, message: PNMessageResult) {
        // Log or process message
        println("Message: ${message.message}")
    }

    override fun signal(pubnub: PubNub, signal: PNSignalResult) {
        // Handle signals
        println("Signal: ${signal.message}")
    }

    override fun messageAction(pubnub: PubNub, messageAction: PNMessageActionResult) {
        // Handle message reactions
        println("Message Reaction: ${messageAction.data}")
    }

    override fun file(pubnub: PubNub, file: PNFileEventResult) {
        // Handle file events
        println("File: ${file.file.name}")
    }

    override fun objects(pubnub: PubNub, obj: PNObjectEventResult) {
        // Handle metadata updates
        println("App Context: ${obj.event}")
    }

    override fun presence(pubnub: PubNub, presence: PNPresenceEventResult) {
        // Handle presence updates
        // requires a subscription with presence
        println("Presence: ${presence.uuid} - ${presence.event}")
    }
})

// Adding the status listener to the PubNub client
pubnub.addListener(object : StatusListener() {
    override fun status(pubnub: PubNub, status: PNStatus) {
        // This block is executed asynchronously for each status update
        println("Connection Status: ${status.category}")
    }
})

// for subscription set
val subscriptionSet = pubnub.subscriptionSetOf(
    // Specify channels with default options
    channels = setOf("my_channel", "other_channel"),
)

subscriptionSet.addListener(object : EventListener {
    override fun message(pubnub: PubNub, message: PNMessageResult) {
        // Log or process message
        println("Message: ${message.message}")
    }
})

Add event listeners old way

pubnub.addListener(object : SubscribeCallback() {

    override fun status(pubnub: PubNub, status: PNStatus) {
        println("Status category: ${status.category}")
        // PNConnectedCategory, PNReconnectedCategory, PNDisconnectedCategory

        println("Status operation: ${status.operation}")
        // PNSubscribeOperation, PNHeartbeatOperation

        println("Status error: ${status.error}")
        // true or false
    }

    override fun presence(pubnub: PubNub, pnPresenceEventResult: PNPresenceEventResult) {
        println("Presence event: ${pnPresenceEventResult.event}")
        println("Presence channel: ${pnPresenceEventResult.channel}")
        println("Presence uuid: ${pnPresenceEventResult.uuid}")
        println("Presence timetoken: ${pnPresenceEventResult.timetoken}")
        println("Presence occupancy: ${pnPresenceEventResult.occupancy}")
    }

    override fun message(pubnub: PubNub, pnMessageResult: PNMessageResult) {
        println("Message payload: ${pnMessageResult.message}")
        println("Message channel: ${pnMessageResult.channel}")
        println("Message publisher: ${pnMessageResult.publisher}")
        println("Message timetoken: ${pnMessageResult.timetoken}")
    }

    override fun signal(pubnub: PubNub, pnSignalResult: PNSignalResult) {
        println("Signal payload: ${pnSignalResult.message}")
        println("Signal channel: ${pnSignalResult.channel}")
        println("Signal publisher: ${pnSignalResult.publisher}")
        println("Signal timetoken: ${pnSignalResult.timetoken}")
    }

    override fun messageAction(pubnub: PubNub, pnMessageActionResult: PNMessageActionResult) {
        with(pnMessageActionResult.messageAction) {
            println("Message action type: $type")
            println("Message action value: $value")
            println("Message action uuid: $uuid")
            println("Message action actionTimetoken: $actionTimetoken")
            println("Message action messageTimetoken: $messageTimetoken")
        }

        println("Message action subscriptions: ${pnMessageActionResult.subscription}")
        println("Message action channel: ${pnMessageActionResult.channel}")
        println("Message action timetoken: ${pnMessageActionResult.timetoken}")
    }
})

Subscribe

subscription.subscribe()

Subscribe old way

pubnub.subscribe(channels = listOf("my_channel"), withPresence = true)

Publish

    val channel = pubnub.channel("my_channel")
    channel.publish(message = "hello").async { result ->
        result.onSuccess { response ->
            println("Message timetoken: ${response.timetoken}")
        }.onFailure { exception ->
            println("ERROR: Failed to publish message")
            println("Error details: ${exception.message}")
        }
    }

Publish old way

pubnub.publish(channel = "my_channel", message = "hello")
    .async { result -> 
    // the result is always of a nullable type
    // it's null if there were errors (status.error)
    // otherwise it's usable

    // handle publish result
    result.onSuccess { res ->
        println("Message timetoken: ${res!!.timetoken}")
    }.onFailure { exception ->
        // handle error
        exception.printStackTrace()
    }
}

pubnub.subscribe(channels = listOf("my_channel"))

Documentation

• API reference for Kotlin
• API reference for Java

Support

If you need help or have a general question, contact support@pubnub.com.