I am trying to implement a cometD client in a Kotlin Multiplatform App for android at the moment.
val androidMain by getting {
dependencies {
implementation("org.cometd.java:cometd-java-client-websocket-okhttp:7.0.5")
implementation("org.cometd.java:cometd-java-client-websocket-javax:7.0.5")
}
}
package com.roxorgaming.kotlinheadlessspike
import jakarta.websocket.ContainerProvider
import org.cometd.client.BayeuxClient
import org.cometd.client.websocket.javax.WebSocketTransport
import org.cometd.client.transport.ClientTransport
actual class CometdConnection actual constructor() {
private lateinit var bayeuxClient: BayeuxClient
actual fun initialise() {
// Prepare the JSR 356 WebSocket transport.
// Create a JSR 356 WebSocketContainer using the standard APIs.
val webSocketContainer = ContainerProvider.getWebSocketContainer() //<--- this is where it fails
// Create the CometD JSR 356 websocket transport.
val wsTransport: ClientTransport = WebSocketTransport(null, null, webSocketContainer)
// Configure BayeuxClient, with the websocket transport listed before the long-polling transport.
bayeuxClient = BayeuxClient("http://localhost:8080/cometd", wsTransport)
}
actual fun handshake() {
// Handshake with the server.
bayeuxClient.handshake()
}
}
The app gets compiled but crashes when the initialization fails with an error
2021-12-06 11:18:09.234 19121-19121/com.roxorgaming.kotlinheadlessspike.android E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.roxorgaming.kotlinheadlessspike.android, PID: 19121
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.roxorgaming.kotlinheadlessspike.android/com.roxorgaming.kotlinheadlessspike.android.MainActivity}: java.lang.RuntimeException: Could not find an implementation class.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3449)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
Caused by: java.lang.RuntimeException: Could not find an implementation class.
at jakarta.websocket.ContainerProvider.getWebSocketContainer(ContainerProvider.java:54)
at com.roxorgaming.kotlinheadlessspike.CometdConnection.initialise(CometdConnection.kt:16)
at com.roxorgaming.kotlinheadlessspike.android.MainActivity.onCreate(MainActivity.kt:20)
at android.app.Activity.performCreate(Activity.java:7994)
at android.app.Activity.performCreate(Activity.java:7978)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
You don't need dependency org.cometd.java:cometd-java-client-websocket-javax:7.0.5
because you already have org.cometd.java:cometd-java-client-websocket-okhttp:7.0.5
.
Remove it and the error should go away.