Kotlin DSL

Kotlin DSL

Builder API and coroutine extensions for Atmosphere.

Maven Coordinates

<dependency>
    <groupId>org.atmosphere</groupId>
    <artifactId>atmosphere-kotlin</artifactId>
    <version>LATEST</version> <!-- check Maven Central for latest -->
</dependency>

DSL Builder

Create AtmosphereHandler instances with a type-safe DSL:

import org.atmosphere.kotlin.atmosphere

val handler = atmosphere {
    onConnect { resource ->
        println("${resource.uuid()} connected via ${resource.transport()}")
    }
    onMessage { resource, message ->
        resource.broadcaster.broadcast(message)
    }
    onDisconnect { resource ->
        println("${resource.uuid()} left")
    }
    onTimeout { resource ->
        println("${resource.uuid()} timed out")
    }
    onResume { resource ->
        println("${resource.uuid()} resumed")
    }
}

framework.addAtmosphereHandler("/chat", handler)

Available callbacks

Callback	Description
onConnect	Called when a client connects
onMessage	Called when a message is received
onDisconnect	Called when a client disconnects
onTimeout	Called when a connection times out
onResume	Called when a suspended connection resumes

Coroutine Extensions

Suspending versions of blocking Atmosphere methods:

// Suspend instead of blocking on broadcast
broadcaster.broadcastSuspend("Hello!")

// Broadcast to a specific resource
broadcaster.broadcastSuspend("Private message", resource)

// Suspend instead of blocking on write
resource.writeSuspend("Direct message")
resource.writeSuspend(byteArrayOf(0x01, 0x02))

These extensions use kotlinx.coroutines to bridge Atmosphere’s Future-based API into structured concurrency.

Samples

• Spring Boot Chat — can be used with Kotlin DSL

See Also

• Core Runtime — AtmosphereHandler, Broadcaster, AtmosphereResource